Map lighting by the time of day, lit tiles and events; A2 autotiles

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

locale/es.properties

@@ -0,0 +1,2 @@
+mod_rpg_name = Mundo RPG
+mod_rpg_desc = Mundo de casillas visto desde arriba al estilo de RPG Maker: tres capas de casillas y una de colisiones, movimiento por cuadrícula con WASD, eventos con la tecla de acción E/F, encuentros aleatorios y combates que vuelven al mapa.

locale/ja.properties

@@ -0,0 +1,2 @@
+mod_rpg_name = RPG ワールド
+mod_rpg_desc = RPG Maker 風の見下ろし型タイルワールド：3 つのタイルレイヤーと衝突レイヤー、WASD でのマス目移動、アクションキー E/F のイベント、ランダムエンカウント、マップに戻ってくるバトル。

locale/ko.properties

@@ -0,0 +1,2 @@
+mod_rpg_name = RPG 월드
+mod_rpg_desc = RPG Maker 스타일의 탑다운 타일 월드: 타일 레이어 3개와 충돌 레이어, WASD 격자 이동, 액션 키 E/F 이벤트, 랜덤 인카운터, 맵으로 돌아오는 전투.

locale/schema_en.properties

@@ -0,0 +1,10 @@
+rpg/schema/builtin/rpg_battle = Battle from the map
+rpg/schema/builtin/rpg_battle_desc = Enemies, comma separated; the win flag is set on victory
+rpg/schema/field/enemies = Enemies
+rpg/schema/field/win_flag = Win flag
+rpg/schema/builtin/rpg_teleport = Teleport on the map
+rpg/schema/builtin/rpg_teleport_desc = A cell and a facing; the map is optional
+rpg/schema/field/map = Map
+rpg/schema/field/x = X
+rpg/schema/field/y = Y
+rpg/schema/field/dir = Facing

locale/schema_es.properties

@@ -0,0 +1,10 @@
+rpg/schema/builtin/rpg_battle = Combate desde el mapa
+rpg/schema/builtin/rpg_battle_desc = Enemigos separados por comas; la marca de victoria se pone al ganar
+rpg/schema/field/enemies = Enemigos
+rpg/schema/field/win_flag = Marca de victoria
+rpg/schema/builtin/rpg_teleport = Teletransportar en el mapa
+rpg/schema/builtin/rpg_teleport_desc = Una casilla y una dirección; el mapa es opcional
+rpg/schema/field/map = Mapa
+rpg/schema/field/x = X
+rpg/schema/field/y = Y
+rpg/schema/field/dir = Dirección

locale/schema_ja.properties

@@ -0,0 +1,10 @@
+rpg/schema/builtin/rpg_battle = マップからの戦闘
+rpg/schema/builtin/rpg_battle_desc = 敵はカンマ区切り。勝つと勝利フラグが立つ
+rpg/schema/field/enemies = 敵
+rpg/schema/field/win_flag = 勝利フラグ
+rpg/schema/builtin/rpg_teleport = マップ上で移動
+rpg/schema/builtin/rpg_teleport_desc = マスと向き。マップは任意
+rpg/schema/field/map = マップ
+rpg/schema/field/x = X
+rpg/schema/field/y = Y
+rpg/schema/field/dir = 向き

locale/schema_ko.properties

@@ -0,0 +1,10 @@
+rpg/schema/builtin/rpg_battle = 맵에서 전투
+rpg/schema/builtin/rpg_battle_desc = 적은 쉼표로 구분. 이기면 승리 플래그 설정
+rpg/schema/field/enemies = 적
+rpg/schema/field/win_flag = 승리 플래그
+rpg/schema/builtin/rpg_teleport = 맵에서 이동
+rpg/schema/builtin/rpg_teleport_desc = 칸과 방향. 맵은 선택
+rpg/schema/field/map = 맵
+rpg/schema/field/x = X
+rpg/schema/field/y = Y
+rpg/schema/field/dir = 방향

locale/schema_ru.properties

@@ -0,0 +1,10 @@
+rpg/schema/builtin/rpg_battle = Бой с карты
+rpg/schema/builtin/rpg_battle_desc = Враги через запятую; флаг победы ставится при выигрыше
+rpg/schema/field/enemies = Враги
+rpg/schema/field/win_flag = Флаг победы
+rpg/schema/builtin/rpg_teleport = Переместить на карте
+rpg/schema/builtin/rpg_teleport_desc = Клетка и направление; карта — по желанию
+rpg/schema/field/map = Карта
+rpg/schema/field/x = X
+rpg/schema/field/y = Y
+rpg/schema/field/dir = Направление

locale/schema_vi.properties

@@ -0,0 +1,10 @@
+rpg/schema/builtin/rpg_battle = Trận đấu từ bản đồ
+rpg/schema/builtin/rpg_battle_desc = Kẻ địch cách nhau bằng dấu phẩy; thắng thì đặt cờ chiến thắng
+rpg/schema/field/enemies = Kẻ địch
+rpg/schema/field/win_flag = Cờ chiến thắng
+rpg/schema/builtin/rpg_teleport = Dịch chuyển trên bản đồ
+rpg/schema/builtin/rpg_teleport_desc = Ô và hướng; bản đồ tùy chọn
+rpg/schema/field/map = Bản đồ
+rpg/schema/field/x = X
+rpg/schema/field/y = Y
+rpg/schema/field/dir = Hướng

locale/schema_zh.properties

@@ -0,0 +1,10 @@
+rpg/schema/builtin/rpg_battle = 地图上的战斗
+rpg/schema/builtin/rpg_battle_desc = 敌人以逗号分隔；获胜时设置胜利标记
+rpg/schema/field/enemies = 敌人
+rpg/schema/field/win_flag = 胜利标记
+rpg/schema/builtin/rpg_teleport = 地图传送
+rpg/schema/builtin/rpg_teleport_desc = 格子和朝向；地图可选
+rpg/schema/field/map = 地图
+rpg/schema/field/x = X
+rpg/schema/field/y = Y
+rpg/schema/field/dir = 朝向

locale/vi.properties

@@ -0,0 +1,2 @@
+mod_rpg_name = Thế giới RPG
+mod_rpg_desc = Thế giới ô nhìn từ trên xuống theo phong cách RPG Maker: ba lớp ô và một lớp va chạm, di chuyển theo lưới bằng WASD, sự kiện bằng phím hành động E/F, chạm trán ngẫu nhiên và các trận chiến quay về bản đồ.

locale/zh.properties

@@ -0,0 +1,2 @@
+mod_rpg_name = RPG 世界
+mod_rpg_desc = RPG Maker 风格的俯视瓦片世界：三层瓦片和一层碰撞层，用 WASD 按网格行走，用动作键 E/F 触发事件，随机遇敌，战斗结束后回到地图。

manifest.json

@@ -11,7 +11,7 @@
   "test_sources": [
     "tests/*.cs"
   ],
-  "depends": ["shell2d_base>=1", "ui_base>=1", "dialog_base>=1", "turn_battle_base>=2"],
+  "depends": ["shell2d_base>=1", "ui_base>=1", "time_base>=1", "dialog_base>=1", "turn_battle_base>=2"],
   "test_suites": [
     {"id": "walk", "activate": ["--itest=rpg_walk"]}
   ]

schemas/rpg.json

@@ -0,0 +1,61 @@
+{
+  "Actions": [
+    {
+      "Id": "rpg.battle",
+      "Name": "rpg/schema/builtin/rpg_battle",
+      "Description": "rpg/schema/builtin/rpg_battle_desc",
+      "Category": "battle",
+      "Params": [
+        {
+          "Key": "enemies",
+          "Type": "ref_list",
+          "Kind": "character",
+          "Required": true,
+          "Name": "rpg/schema/field/enemies"
+        },
+        {
+          "Key": "win_flag",
+          "Type": "flag",
+          "Name": "rpg/schema/field/win_flag"
+        }
+      ]
+    },
+    {
+      "Id": "rpg.teleport",
+      "Name": "rpg/schema/builtin/rpg_teleport",
+      "Description": "rpg/schema/builtin/rpg_teleport_desc",
+      "Category": "world",
+      "Params": [
+        {
+          "Key": "map",
+          "Type": "ref",
+          "Kind": "rpg_map",
+          "Name": "rpg/schema/field/map"
+        },
+        {
+          "Key": "x",
+          "Type": "int",
+          "Required": true,
+          "Name": "rpg/schema/field/x"
+        },
+        {
+          "Key": "y",
+          "Type": "int",
+          "Required": true,
+          "Name": "rpg/schema/field/y"
+        },
+        {
+          "Key": "dir",
+          "Type": "choice",
+          "Options": [
+            "Up",
+            "Down",
+            "Left",
+            "Right"
+          ],
+          "Name": "rpg/schema/field/dir"
+        }
+      ]
+    }
+  ]
+}

shaders/rpg_lit.gdshader

@@ -0,0 +1,47 @@
+shader_type canvas_item;
+
+// Light of an RPG map (RpgLighting): the tiles and actors are multiplied by the ambient
+// colour of the time of day (time_weights blends the four phases like timed_sprite), and
+// point lights (the player, lit events) add to it. Lights only add up to white, so by day
+// they are invisible and at night they open circles in the dark. Positions and radii are
+// in canvas pixels, the space of world_pos below.
+
+uniform vec4 day_color : source_color = vec4(1.0, 1.0, 1.0, 1.0);
+uniform vec4 morning_color : source_color = vec4(0.86, 0.72, 0.84, 1.0);
+uniform vec4 evening_color : source_color = vec4(0.84, 0.72, 0.92, 1.0);
+uniform vec4 night_color : source_color = vec4(0.2, 0.26, 0.42, 1.0);
+uniform vec4 time_weights = vec4(0.0, 1.0, 0.0, 0.0);
+
+// A map that sets its own ambient (indoors) uses it instead of the time of day.
+uniform bool use_ambient = false;
+uniform vec4 ambient_color : source_color = vec4(1.0, 1.0, 1.0, 1.0);
+
+uniform vec2 light_positions[16];
+uniform vec4 light_colors[16];
+uniform float light_radii[16];
+uniform int light_count = 0;
+
+varying vec2 world_pos;
+
+void vertex() {
+	world_pos = (MODEL_MATRIX * vec4(VERTEX, 0.0, 1.0)).xy;
+}
+
+void fragment() {
+	vec4 color = texture(TEXTURE, UV) * COLOR;
+
+	vec3 ambient = use_ambient
+		? ambient_color.rgb
+		: (morning_color * time_weights.x + day_color * time_weights.y
+			+ evening_color * time_weights.z + night_color * time_weights.w).rgb;
+
+	vec3 light = vec3(0.0);
+	for (int i = 0; i < 16; i++) {
+		if (i >= light_count)
+			break;
+		float k = clamp(1.0 - distance(world_pos, light_positions[i]) / max(light_radii[i], 1.0), 0.0, 1.0);
+		light += light_colors[i].rgb * light_colors[i].a * k * k;
+	}
+
+	COLOR = vec4(color.rgb * min(ambient + light, vec3(1.0)), color.a);
+}

src/Data/RpgAutotiles.cs

@@ -0,0 +1,84 @@
+using Godot;
+
+namespace Cthangover.Mods.Rpg
+{
+    /// <summary>
+    /// Autotiles in the RPG Maker A2 layout: one picture of 2×3 tiles describes a terrain
+    /// (water, a path, a cliff top), and each map cell is assembled from four quarter tiles
+    /// chosen by its eight neighbours — so an author paints "water" and the shores draw
+    /// themselves. A tileset entry becomes an autotile by naming that picture
+    /// (<see cref="RpgTileInfo.Autotile"/>); its index is any number outside the atlas.
+    /// <para/>
+    /// The block in quarter units (4 columns × 6 rows): the top-left tile is the palette
+    /// preview; the top-right tile holds the four inner corners; the 2×2 tiles below are a
+    /// framed patch whose outer ring gives outer corners and edges and whose middle gives the
+    /// fill. For a quarter, the two neighbours along its sides and the one across its corner
+    /// decide: both sides alike and the corner too — fill; both sides alike but not the
+    /// corner — inner corner; only one side alike — the edge along the other; none — the
+    /// outer corner. Cells past the map edge count as alike, so a terrain runs off the map
+    /// without a border. The world (<see cref="RpgAutotileLayer"/>) and the map editor draw
+    /// through <see cref="Quarters"/> and <see cref="Draw"/>, so both show the same cells.
+    /// </summary>
+    public static class RpgAutotiles
+    {
+        /// <summary>
+        /// Source quarters (in quarter units of the block) for the top-left, top-right,
+        /// bottom-left and bottom-right quarter of a cell, from which neighbours are alike.
+        /// </summary>
+        public static Vector2I[] Quarters(bool up, bool down, bool left, bool right,
+            bool upLeft, bool upRight, bool downLeft, bool downRight)
+        {
+            return new[]
+            {
+                Quarter(up, left, upLeft, new Vector2I(2, 0), left ? 2 : 0, up ? 4 : 2),
+                Quarter(up, right, upRight, new Vector2I(3, 0), right ? 1 : 3, up ? 4 : 2),
+                Quarter(down, left, downLeft, new Vector2I(2, 1), left ? 2 : 0, down ? 3 : 5),
+                Quarter(down, right, downRight, new Vector2I(3, 1), right ? 1 : 3, down ? 3 : 5),
+            };
+        }
+
+        /// <summary>
+        /// The quarters of the cell (<paramref name="x"/>, <paramref name="y"/>) of
+        /// <paramref name="layer"/>, whose tile is the autotile <paramref name="index"/>.
+        /// </summary>
+        public static Vector2I[] QuartersAt(RpgMapGrid grid, RpgLayer layer, int x, int y, int index)
+        {
+            return Quarters(
+                Alike(grid, layer, x, y - 1, index), Alike(grid, layer, x, y + 1, index),
+                Alike(grid, layer, x - 1, y, index), Alike(grid, layer, x + 1, y, index),
+                Alike(grid, layer, x - 1, y - 1, index), Alike(grid, layer, x + 1, y - 1, index),
+                Alike(grid, layer, x - 1, y + 1, index), Alike(grid, layer, x + 1, y + 1, index));
+        }
+
+        /// <summary>Pixel rectangle of a quarter in the block picture of a tileset with <paramref name="tileSize"/>.</summary>
+        public static Rect2 SourceRect(Vector2I quarter, int tileSize)
+        {
+            var half = tileSize / 2f;
+            return new Rect2(quarter.X * half, quarter.Y * half, half, half);
+        }
+
+        /// <summary>Draws a cell of an autotile into <paramref name="cell"/> on <paramref name="target"/>.</summary>
+        public static void Draw(CanvasItem target, Texture2D block, Rect2 cell, Vector2I[] quarters, int tileSize, Color modulate)
+        {
+            var half = cell.Size / 2f;
+            for (var i = 0; i < 4; i++)
+            {
+                var offset = new Vector2(i % 2 * half.X, i / 2 * half.Y);
+                target.DrawTextureRectRegion(block, new Rect2(cell.Position + offset, half), SourceRect(quarters[i], tileSize), modulate);
+            }
+        }
+
+        /// <summary>Source rectangle of the block's preview tile (its top-left tile), for palettes.</summary>
+        public static Rect2 PreviewRect(int tileSize) => new(0, 0, tileSize, tileSize);
+
+        private static Vector2I Quarter(bool sideA, bool sideB, bool corner, Vector2I inner, int column, int row)
+        {
+            if (sideA && sideB && !corner)
+                return inner;
+            return new Vector2I(column, row);
+        }
+
+        private static bool Alike(RpgMapGrid grid, RpgLayer layer, int x, int y, int index)
+            => !grid.InBounds(x, y) || grid.GetTile(layer, x, y) == index;
+    }
+}

src/Data/RpgEventPage.cs

@@ -0,0 +1,50 @@
+using System.Collections.Generic;
+
+namespace Cthangover.Mods.Rpg
+{
+    /// <summary>
+    /// One page of a map event, as in RPG Maker: the event's look and effect while the
+    /// page's <see cref="Condition"/> holds. Every field left out (null) is the event's
+    /// own; an empty <see cref="Sprite"/>/<see cref="Icon"/> clears it. The last page whose
+    /// condition holds is the active one; the event's own fields are page 0 and count only
+    /// while the event's own condition holds (<see cref="RpgEventPages"/>).
+    /// </summary>
+    public class RpgEventPage
+    {
+        /// <summary>Scenario condition of the page; empty = always.</summary>
+        public string Condition { get; set; }
+
+        /// <summary>Charset of the page ("" = none).</summary>
+        public string Sprite { get; set; }
+
+        /// <summary>Atlas tile of the page (-1 = none).</summary>
+        public int? Tile { get; set; }
+
+        /// <summary>Item icon of the page ("" = none).</summary>
+        public string Icon { get; set; }
+
+        /// <summary>Facing the event turns to when the page becomes active.</summary>
+        public RpgDirection? Dir { get; set; }
+
+        /// <summary>How the page starts.</summary>
+        public RpgEventTrigger? Trigger { get; set; }
+
+        /// <summary>Whether the page blocks walking.</summary>
+        public bool? Solid { get; set; }
+
+        /// <summary>Scenario file of the page.</summary>
+        public string Scenario { get; set; }
+
+        /// <summary>Inline scenario lines of the page.</summary>
+        public List<string> Commands { get; set; }
+
+        /// <summary>Teleport of the page.</summary>
+        public RpgTeleport Teleport { get; set; }
+
+        /// <summary>Autonomous movement of the page.</summary>
+        public RpgMoveRoute Route { get; set; }
+
+        /// <summary>Light of the page (a lamp lit by a page).</summary>
+        public RpgLight Light { get; set; }
+    }
+}

src/Data/RpgEventPages.cs

@@ -0,0 +1,73 @@
+using System;
+using System.Collections.Generic;
+
+namespace Cthangover.Mods.Rpg
+{
+    /// <summary>
+    /// Picks the active page of an event and builds the event as that page shows it. Page
+    /// index 0 is the event's own fields (active while the event's own condition holds),
+    /// 1… are <see cref="RpgMapEvent.Pages"/>; the last page whose condition holds wins, -1
+    /// means none holds and the event is hidden. Pure: the caller passes the condition check.
+    /// </summary>
+    public static class RpgEventPages
+    {
+        /// <summary>The index of the active page, or -1.</summary>
+        public static int ActiveIndex(RpgMapEvent mapEvent, Func<string, bool> holds)
+        {
+            if (mapEvent == null)
+                return -1;
+            var pages = mapEvent.Pages;
+            if (pages != null)
+            {
+                for (var i = pages.Count - 1; i >= 0; i--)
+                {
+                    if (pages[i] != null && Holds(pages[i].Condition, holds))
+                        return i + 1;
+                }
+            }
+            return Holds(mapEvent.Condition, holds) ? 0 : -1;
+        }
+
+        /// <summary>
+        /// The event as page <paramref name="index"/> shows it: the event itself for 0, else a
+        /// copy with the page's fields over the event's. Null for an index out of range.
+        /// </summary>
+        public static RpgMapEvent Effective(RpgMapEvent mapEvent, int index)
+        {
+            if (mapEvent == null || index < 0)
+                return null;
+            if (index == 0)
+                return mapEvent;
+            if (mapEvent.Pages == null || index > mapEvent.Pages.Count || mapEvent.Pages[index - 1] == null)
+                return null;
+
+            var page = mapEvent.Pages[index - 1];
+            var hasLook = page.Sprite != null || page.Tile.HasValue || page.Icon != null;
+            return new RpgMapEvent
+            {
+                Id = mapEvent.Id,
+                X = mapEvent.X,
+                Y = mapEvent.Y,
+                // A page that names any look replaces the whole look, so a chest page with an
+                // Icon does not keep the closed chest's Tile underneath it.
+                Sprite = hasLook ? page.Sprite : mapEvent.Sprite,
+                Tile = hasLook ? page.Tile ?? -1 : mapEvent.Tile,
+                Icon = hasLook ? page.Icon : mapEvent.Icon,
+                Dir = page.Dir ?? mapEvent.Dir,
+                Trigger = page.Trigger ?? mapEvent.Trigger,
+                Solid = page.Solid ?? (hasLook ? null : mapEvent.Solid),
+                Scenario = page.Scenario ?? mapEvent.Scenario,
+                Commands = page.Commands ?? mapEvent.Commands,
+                Teleport = page.Teleport ?? mapEvent.Teleport,
+                Route = page.Route ?? mapEvent.Route,
+                Light = page.Light ?? mapEvent.Light,
+                Condition = page.Condition,
+                ModId = mapEvent.ModId,
+                File = mapEvent.File,
+            };
+        }
+
+        private static bool Holds(string condition, Func<string, bool> holds)
+            => string.IsNullOrWhiteSpace(condition) || (holds != null && holds(condition));
+    }
+}

src/Data/RpgLight.cs

@@ -0,0 +1,16 @@
+namespace Cthangover.Mods.Rpg
+{
+    /// <summary>
+    /// A light an event gives off (a lamp, a fire, a lit window), drawn by
+    /// <see cref="RpgLighting"/>. It brightens the cells around the event towards their
+    /// own colours, so it shows at dusk and at night and is lost in daylight.
+    /// </summary>
+    public class RpgLight
+    {
+        /// <summary>Reach in cells from the event's centre; the light fades to nothing there.</summary>
+        public float Radius { get; set; } = 3f;
+
+        /// <summary>Colour (<c>#rrggbb</c>, optionally <c>#rrggbbaa</c>: alpha is the strength).</summary>
+        public string Color { get; set; } = "#ffd8a0";
+    }
+}

src/Data/RpgMap.cs

@@ -16,7 +16,10 @@ namespace Cthangover.Mods.Rpg
     /// <para/>
     /// Files declare <c>"Kind": "rpg_map"</c>. Layers are parsed by
     /// <see cref="RpgMapGrid"/>; a dependent mod replaces a whole map by id, the
-    /// usual entity override.
+    /// usual entity override. The map file holds only the ground: what stands on it
+    /// (NPCs, doors, chests, pickups) are events in <c>map_events/&lt;id&gt;/</c> of any
+    /// mod, merged by <see cref="RpgMapEventResolver"/>, so a mod adds to another
+    /// mod's map without replacing it.
     /// </summary>
     [EntityKind("rpg_map")]
     public class RpgMap : IIdentifiable
@@ -49,10 +52,14 @@ namespace Cthangover.Mods.Rpg
         /// <summary>Where the player appears when entering the map without a teleport target.</summary>
         public RpgTeleport Spawn { get; set; } = new();
 
-        /// <summary>Events placed on the map.</summary>
-        public List<RpgMapEvent> Events { get; set; } = new();
 
         /// <summary>Random battles; null for a safe map.</summary>
         public RpgEncounterTable Encounters { get; set; }
+
+        /// <summary>
+        /// Fixed light colour of the map (<c>#rrggbb</c>), e.g. a lit room; null = the time of day
+        /// lights the map (<see cref="RpgLighting"/>).
+        /// </summary>
+        public string Ambient { get; set; }
     }
 }

src/Data/RpgMapEvent.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Text.Json.Serialization;
 
 namespace Cthangover.Mods.Rpg
 {
@@ -7,7 +8,7 @@ namespace Cthangover.Mods.Rpg
     /// RPG Maker events: an NPC, a sign, a chest, a door. What it looks like and
     /// what it does are independent:
     /// <list type="bullet">
-    /// <item>look — a charset <see cref="Sprite"/>, or one atlas <see cref="Tile"/>, or nothing (an invisible trigger);</item>
+    /// <item>look — a charset <see cref="Sprite"/>, or one atlas <see cref="Tile"/>, or an item <see cref="Icon"/>, or nothing (an invisible trigger);</item>
     /// <item>effect — a <see cref="Teleport"/>, handled natively, or a dialog built
     /// from a <see cref="Scenario"/> file followed by inline <see cref="Commands"/>
     /// (the full scenario DSL, so <c>action rpg.battle …</c>, <c>flag …</c>, quests).</item>
@@ -15,6 +16,9 @@ namespace Cthangover.Mods.Rpg
     /// A <see cref="Condition"/> in the scenario condition language hides the
     /// event while false; it is re-checked whenever game state changes, so a
     /// defeated boss (<c>flag boss_dead 1</c>) disappears at once.
+    /// <para/>
+    /// Events are stored apart from their map, in <c>map_events/&lt;map&gt;/*.json</c>
+    /// of any mod (<see cref="RpgMapEventResolver"/>).
     /// </summary>
     public class RpgMapEvent
     {
@@ -33,13 +37,19 @@ namespace Cthangover.Mods.Rpg
         /// <summary>Atlas index of the map's tileset drawn as the event when it has no sprite; -1 for none.</summary>
         public int Tile { get; set; } = -1;
 
+        /// <summary>
+        /// Picture in the <c>items</c> group (what an item's <c>Sprite</c> names), drawn fitted into the
+        /// cell when the event has neither a sprite nor a tile: an item lying on the ground.
+        /// </summary>
+        public string Icon { get; set; }
+
         /// <summary>Initial facing of a sprite.</summary>
         public RpgDirection Dir { get; set; } = RpgDirection.Down;
 
         /// <summary>When the event fires.</summary>
         public RpgEventTrigger Trigger { get; set; } = RpgEventTrigger.Action;
 
-        /// <summary>The event occupies its cell. Null means "solid when it is visible" (a sprite or a tile).</summary>
+        /// <summary>The event occupies its cell. Null means "solid when it is visible" (a sprite, a tile or an icon).</summary>
         public bool? Solid { get; set; }
 
         /// <summary>Scenario path inside the <c>scenarios</c> group (extension optional), played as a dialog.</summary>
@@ -54,7 +64,29 @@ namespace Cthangover.Mods.Rpg
         /// <summary>Scenario condition; the event exists only while it is true.</summary>
         public string Condition { get; set; }
 
+        /// <summary>
+        /// Further pages (RPG Maker's event pages): the last one whose condition holds replaces
+        /// the event's look and effect; with pages, a false own <see cref="Condition"/> only
+        /// turns off page 0 (<see cref="RpgEventPages"/>).
+        /// </summary>
+        public List<RpgEventPage> Pages { get; set; }
+
+        /// <summary>Autonomous movement (<see cref="RpgMoveRoute"/>); null = the event stands still.</summary>
+        public RpgMoveRoute Route { get; set; }
+
+        /// <summary>Light the event gives off (<see cref="RpgLight"/>); null = none.</summary>
+        public RpgLight Light { get; set; }
+
+        /// <summary>Mod the event was read from (set by the event resolver, not stored).</summary>
+        [JsonIgnore]
+        public string ModId { get; set; }
+
+        /// <summary>Mod-relative path of the file the event was read from (set by the event resolver, not stored).</summary>
+        [JsonIgnore]
+        public string File { get; set; }
+
         /// <summary>Effective solidity: explicit value, else whether the event is drawn.</summary>
-        public bool IsSolid => Solid ?? (!string.IsNullOrEmpty(Sprite) || Tile >= 0);
+        [JsonIgnore]
+        public bool IsSolid => Solid ?? (!string.IsNullOrEmpty(Sprite) || Tile >= 0 || !string.IsNullOrEmpty(Icon));
     }
 }

src/Data/RpgMapEventFile.cs

@@ -0,0 +1,15 @@
+using System.Collections.Generic;
+
+namespace Cthangover.Mods.Rpg
+{
+    /// <summary>
+    /// One file of map events, <c>map_events/&lt;map id&gt;/&lt;any name&gt;.json</c>:
+    /// <c>{"Events": [ … ]}</c>. The folder names the map, so a file holds the events
+    /// of one map, and a mod may split them over as many files as it likes.
+    /// </summary>
+    public class RpgMapEventFile
+    {
+        /// <summary>The events of the file, in drawing order.</summary>
+        public List<RpgMapEvent> Events { get; set; } = new();
+    }
+}

src/Data/RpgMapEventMerge.cs

@@ -0,0 +1,53 @@
+using System;
+using System.Collections.Generic;
+
+namespace Cthangover.Mods.Rpg
+{
+    /// <summary>
+    /// Builds the event list of every map from event files read in mod load order.
+    /// A new id is appended; an id already present (ignoring case) is replaced in
+    /// place, so the later file wins and keeps the original's drawing order. Mods
+    /// load after their dependencies, so the engine's replacement rule holds:
+    /// ship the same event id and declare <c>depends</c> on the owner to replace
+    /// it, ship a new id to add to any mod's map.
+    /// <para/>
+    /// Pure data, so the merge rules are tested without a mod set.
+    /// </summary>
+    public class RpgMapEventMerge
+    {
+        /// <summary>Events per map id (case-insensitive).</summary>
+        public Dictionary<string, List<RpgMapEvent>> Maps { get; } = new(StringComparer.OrdinalIgnoreCase);
+
+        /// <summary>
+        /// Adds the events of one file of <paramref name="modId"/> for map <paramref name="map"/>;
+        /// each event gets <see cref="RpgMapEvent.ModId"/> and <see cref="RpgMapEvent.File"/>.
+        /// Returns the ids that replaced an earlier event.
+        /// </summary>
+        public List<string> Add(string map, string modId, string file, IEnumerable<RpgMapEvent> events)
+        {
+            var replaced = new List<string>();
+            if (!Maps.TryGetValue(map, out var list))
+            {
+                list = new List<RpgMapEvent>();
+                Maps[map] = list;
+            }
+
+            foreach (var mapEvent in events ?? Array.Empty<RpgMapEvent>())
+            {
+                if (mapEvent == null || string.IsNullOrWhiteSpace(mapEvent.Id))
+                    continue;
+                mapEvent.ModId = modId;
+                mapEvent.File = file;
+                var index = list.FindIndex(e => string.Equals(e.Id, mapEvent.Id, StringComparison.OrdinalIgnoreCase));
+                if (index < 0)
+                {
+                    list.Add(mapEvent);
+                    continue;
+                }
+                list[index] = mapEvent;
+                replaced.Add(mapEvent.Id);
+            }
+            return replaced;
+        }
+    }
+}

src/Data/RpgMapEventResolver.cs

@@ -0,0 +1,93 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.Json;
+using Cthangover.Core.Mods;
+using Cthangover.Core.Mods.Resolvers;
+using Cthangover.Core.Utils;
+
+namespace Cthangover.Mods.Rpg
+{
+    /// <summary>
+    /// Collects map events from <c>map_events/&lt;map id&gt;/**/*.json</c> of every
+    /// loaded mod in load order (files of one mod sorted by path), then from the
+    /// studio overlays, and merges them per map with <see cref="RpgMapEventMerge"/>.
+    /// <para/>
+    /// Events live apart from the map file (<c>maps/&lt;id&gt;.json</c> holds only
+    /// tiles, collision, spawn and encounters) so that any mod can put its own NPC,
+    /// chest or quest trigger on another mod's map without replacing the map, and
+    /// so that drawing and placing do not fight over one big file. Events of a map
+    /// no mod defines are kept and simply never shown.
+    /// </summary>
+    public class RpgMapEventResolver : ModAssetResolver
+    {
+        /// <summary>Group folder of event files.</summary>
+        public const string Directory = "map_events";
+
+        private Dictionary<string, List<RpgMapEvent>> cache;
+
+        /// <inheritdoc />
+        public override string Id => "rpg_map_events";
+
+        /// <summary>Events per map id, merged; cached until the next mod reload or <see cref="ClearCache"/>.</summary>
+        public Dictionary<string, List<RpgMapEvent>> Collect()
+        {
+            Context.Initialize();
+            if (cache != null)
+                return cache;
+
+            var merge = new RpgMapEventMerge();
+            foreach (var modId in Context.GetOrderedModIds())
+                CollectMod(Context.Mods[modId].FileProvider, modId, merge);
+            foreach (var overlay in ModOverlays.All)
+                CollectMod(overlay.Value, overlay.Key, merge);
+
+            cache = merge.Maps;
+            GameLogger.Log("RPG", $"map events: {cache.Values.Sum(l => l.Count)} event(s) on {cache.Count} map(s)");
+            return cache;
+        }
+
+        /// <inheritdoc />
+        public override void ClearCache() => cache = null;
+
+        private void CollectMod(IModFileProvider provider, string modId, RpgMapEventMerge merge)
+        {
+            foreach (var mapDir in provider.ListFiles(Directory).Where(e => e.EndsWith("/")).OrderBy(e => e, System.StringComparer.Ordinal))
+            {
+                var map = mapDir.TrimEnd('/');
+                map = map.Substring(map.LastIndexOf('/') + 1);
+                var files = new List<string>();
+                ListJson(provider, mapDir.TrimEnd('/'), files);
+                foreach (var file in files.OrderBy(f => f, System.StringComparer.Ordinal))
+                    ReadFile(provider, modId, map, file, merge);
+            }
+        }
+
+        private static void ListJson(IModFileProvider provider, string dir, List<string> files)
+        {
+            foreach (var entry in provider.ListFiles(dir))
+            {
+                if (entry.EndsWith("/"))
+                    ListJson(provider, entry.TrimEnd('/'), files);
+                else if (entry.EndsWith(".json", System.StringComparison.OrdinalIgnoreCase))
+                    files.Add(entry);
+            }
+        }
+
+        private void ReadFile(IModFileProvider provider, string modId, string map, string file, RpgMapEventMerge merge)
+        {
+            var text = Context.ReadResolvedText(modId, file, provider);
+            if (string.IsNullOrWhiteSpace(text))
+                return;
+            try
+            {
+                var data = JsonSerializer.Deserialize<RpgMapEventFile>(text, JsonOptionsProvider.ReadOptions);
+                foreach (var id in merge.Add(map, modId, file, data?.Events))
+                    GameLogger.Log("RPG", $"map '{map}': event '{id}' replaced by mod '{modId}' ({file})");
+            }
+            catch (JsonException ex)
+            {
+                GameLogger.Log("RPG", $"map events '{modId}/{file}': broken JSON: {ex.Message}", LogLevel.Error);
+            }
+        }
+    }
+}

src/Data/RpgMapEvents.cs

@@ -0,0 +1,19 @@
+using System.Collections.Generic;
+using Cthangover.Core.Mods;
+
+namespace Cthangover.Mods.Rpg
+{
+    /// <summary>Access to the merged map events of <see cref="RpgMapEventResolver"/>.</summary>
+    public static class RpgMapEvents
+    {
+        /// <summary>The events of a map (an empty list when it has none); the list is shared, do not change it.</summary>
+        public static IReadOnlyList<RpgMapEvent> Of(string map)
+        {
+            var maps = ModManager.Instance.GetResolver<RpgMapEventResolver>()?.Collect();
+            return map != null && maps != null && maps.TryGetValue(map, out var list) ? list : new List<RpgMapEvent>();
+        }
+
+        /// <summary>Forgets the collected events, so the next <see cref="Of"/> reads the files again (after an editor save).</summary>
+        public static void Invalidate() => ModManager.Instance.GetResolver<RpgMapEventResolver>()?.ClearCache();
+    }
+}

src/Data/RpgMoveRoute.cs

@@ -0,0 +1,25 @@
+using System.Collections.Generic;
+
+namespace Cthangover.Mods.Rpg
+{
+    /// <summary>
+    /// Autonomous movement of an event (RPG Maker's "move route" / "autonomous movement"):
+    /// <c>"Route": { "Steps": ["left", "left", "wait", "right", "right"], "Every": 0.8 }</c>.
+    /// Steps: <c>up</c>, <c>down</c>, <c>left</c>, <c>right</c>, <c>random</c> (a random
+    /// direction), <c>toward</c> / <c>away</c> (relative to the player), <c>wait</c>, and
+    /// <c>face_up</c> … <c>face_right</c> (turn without moving). A step into a blocked cell is
+    /// skipped (the event turns that way). The route pauses while a dialog runs or the player
+    /// cannot walk; positions are not saved, so an event starts from its cell on every visit.
+    /// </summary>
+    public class RpgMoveRoute
+    {
+        /// <summary>The steps, repeated from the start when <see cref="Repeat"/> is set.</summary>
+        public List<string> Steps { get; set; } = new();
+
+        /// <summary>Seconds between steps.</summary>
+        public double Every { get; set; } = 1.0;
+
+        /// <summary>Whether the route starts over after the last step.</summary>
+        public bool Repeat { get; set; } = true;
+    }
+}

src/Data/RpgRouteStep.cs

@@ -0,0 +1,58 @@
+using System;
+using Godot;
+
+namespace Cthangover.Mods.Rpg
+{
+    /// <summary>
+    /// One step of an <see cref="RpgMoveRoute"/> resolved for the current positions: a
+    /// direction (null for <c>wait</c> or an unknown word) and whether the event walks or only
+    /// turns. Pure, so routes are tested without a map.
+    /// </summary>
+    public readonly struct RpgRouteStep
+    {
+        /// <summary>Creates a step.</summary>
+        public RpgRouteStep(RpgDirection? direction, bool moves)
+        {
+            Direction = direction;
+            Moves = moves;
+        }
+
+        /// <summary>Where to walk or turn; null = stand.</summary>
+        public RpgDirection? Direction { get; }
+
+        /// <summary>True for a walk, false for a turn or a wait.</summary>
+        public bool Moves { get; }
+
+        /// <summary>Resolves <paramref name="word"/> (any case) for an event at <paramref name="self"/>.</summary>
+        public static RpgRouteStep Resolve(string word, Vector2I self, Vector2I player, Random random)
+        {
+            var step = (word ?? string.Empty).Trim().ToLowerInvariant();
+            switch (step)
+            {
+                case "up": return new RpgRouteStep(RpgDirection.Up, true);
+                case "down": return new RpgRouteStep(RpgDirection.Down, true);
+                case "left": return new RpgRouteStep(RpgDirection.Left, true);
+                case "right": return new RpgRouteStep(RpgDirection.Right, true);
+                case "face_up": return new RpgRouteStep(RpgDirection.Up, false);
+                case "face_down": return new RpgRouteStep(RpgDirection.Down, false);
+                case "face_left": return new RpgRouteStep(RpgDirection.Left, false);
+                case "face_right": return new RpgRouteStep(RpgDirection.Right, false);
+                case "random": return new RpgRouteStep((RpgDirection)(random ?? Random.Shared).Next(4), true);
+                case "toward": return new RpgRouteStep(Toward(self, player), true);
+                case "away": return new RpgRouteStep(Toward(self, player) is { } d ? RpgDirections.Opposite(d) : null, true);
+                default: return new RpgRouteStep(null, false);
+            }
+        }
+
+        /// <summary>The direction that shortens the longer axis of the distance to <paramref name="target"/>; null when already there.</summary>
+        public static RpgDirection? Toward(Vector2I self, Vector2I target)
+        {
+            var delta = target - self;
+            if (delta == Vector2I.Zero)
+                return null;
+            if (Math.Abs(delta.X) >= Math.Abs(delta.Y))
+                return delta.X > 0 ? RpgDirection.Right : RpgDirection.Left;
+            return delta.Y > 0 ? RpgDirection.Down : RpgDirection.Up;
+        }
+    }
+}

src/Data/RpgTileInfo.cs

@@ -21,5 +21,14 @@ namespace Cthangover.Mods.Rpg
         /// "tree_crown"). Not a locale key: players never see it.
         /// </summary>
         public string Tag { get; set; }
+
+        /// <summary>Light the tile gives off wherever it lies on a map (a lamp, a lit window); null = none.</summary>
+        public RpgLight Light { get; set; }
+
+        /// <summary>
+        /// Picture of an autotile block (RPG Maker A2 layout, see <see cref="RpgAutotiles"/>) in the
+        /// tilesets group; set, the entry is an autotile and <see cref="Index"/> should lie outside the atlas.
+        /// </summary>
+        public string Autotile { get; set; }
     }
 }

src/Data/RpgTileset.cs

@@ -34,6 +34,30 @@ namespace Cthangover.Mods.Rpg
         /// <summary>Per-cell properties; cells without an entry are walkable.</summary>
         public List<RpgTileInfo> Tiles { get; set; } = new();
 
+        /// <summary>The autotile entry with this index (<see cref="RpgTileInfo.Autotile"/> set), or null.</summary>
+        public RpgTileInfo AutotileOf(int index)
+        {
+            if (index < 0)
+                return null;
+            foreach (var tile in Tiles ?? new List<RpgTileInfo>())
+            {
+                if (tile.Index == index && !string.IsNullOrEmpty(tile.Autotile))
+                    return tile;
+            }
+            return null;
+        }
+
+        /// <summary>Light of the atlas cell (<see cref="RpgTileInfo.Light"/>), or null.</summary>
+        public RpgLight LightOf(int index)
+        {
+            foreach (var tile in Tiles ?? new List<RpgTileInfo>())
+            {
+                if (tile.Index == index && tile.Light != null)
+                    return tile.Light;
+            }
+            return null;
+        }
+
         /// <summary>True when the atlas cell blocks walking. Built once from <see cref="Tiles"/>.</summary>
         public bool IsSolid(int index)
         {

src/World/RpgActor.cs

@@ -15,6 +15,7 @@ namespace Cthangover.Mods.Rpg
     /// <see cref="StepFinished"/>. The actor's <see cref="Cell"/> changes at the
     /// start of a step, so two actors never walk into the same cell. The actor
     /// layer sorts children by Y, which keeps whoever is lower in front.
+    /// The sprite uses the actor's material (the map's light, set by the view).
     /// </summary>
     public partial class RpgActor : Node2D
     {
@@ -42,9 +43,21 @@ namespace Cthangover.Mods.Rpg
         /// <summary>True while a step is in progress.</summary>
         public bool IsMoving => progress < 1f;
 
-        /// <summary>The map event this actor shows; null for the player.</summary>
+        /// <summary>The map event this actor shows (its definition, all pages); null for the player.</summary>
         public RpgMapEvent Event { get; }
 
+        /// <summary>The event as its active page shows it (<see cref="RpgEventPages.Effective"/>); null while no page is active.</summary>
+        public RpgMapEvent Current { get; set; }
+
+        /// <summary>Index of the active page (<see cref="RpgEventPages.ActiveIndex"/>); -2 before the first refresh.</summary>
+        public int PageIndex { get; set; } = -2;
+
+        /// <summary>Next step of the active page's route.</summary>
+        public int RouteIndex { get; set; }
+
+        /// <summary>Seconds until the next route step.</summary>
+        public double RouteTimer { get; set; }
+
         /// <summary>Creates an actor for a cell grid of <paramref name="tileSize"/> pixels.</summary>
         public RpgActor(int tileSize, RpgMapEvent mapEvent = null)
         {
@@ -52,12 +65,21 @@ namespace Cthangover.Mods.Rpg
             Event = mapEvent;
         }
 
+        /// <summary>Removes the shown charset, tile or icon (a page change shows another one).</summary>
+        public void ClearLook()
+        {
+            if (sprite == null)
+                return;
+            sprite.QueueFree();
+            sprite = null;
+        }
+
         /// <summary>Shows a charset; a null texture leaves the actor invisible (an invisible trigger).</summary>
         public void UseCharset(Texture2D texture)
         {
             if (texture == null)
                 return;
-            sprite = new Sprite2D { Texture = texture, Hframes = 3, Vframes = 4, Centered = false };
+            sprite = new Sprite2D { Texture = texture, Hframes = 3, Vframes = 4, Centered = false, UseParentMaterial = true };
             var frame = new Vector2(texture.GetWidth() / 3f, texture.GetHeight() / 4f);
             sprite.Position = new Vector2((tileSize - frame.X) / 2f, tileSize - frame.Y);
             AddChild(sprite);
@@ -73,12 +95,33 @@ namespace Cthangover.Mods.Rpg
             {
                 Texture = atlas,
                 Centered = false,
+                UseParentMaterial = true,
                 RegionEnabled = true,
                 RegionRect = new Rect2(atlasCoords * tileSize, new Vector2(tileSize, tileSize)),
             };
             AddChild(sprite);
         }
 
+        /// <summary>
+        /// Shows an item picture fitted into three quarters of the cell and centred on it,
+        /// so an icon of any size lies on the ground like a tile-sized object.
+        /// </summary>
+        public void UseIcon(Texture2D texture)
+        {
+            if (texture == null)
+                return;
+            var fit = tileSize * 0.75f / Mathf.Max(1, Mathf.Max(texture.GetWidth(), texture.GetHeight()));
+            sprite = new Sprite2D
+            {
+                Texture = texture,
+                Position = new Vector2(tileSize, tileSize) / 2f,
+                Scale = new Vector2(fit, fit),
+                TextureFilter = TextureFilterEnum.Linear,
+                UseParentMaterial = true,
+            };
+            AddChild(sprite);
+        }
+
         /// <summary>Puts the actor on a cell at once, stopping any step.</summary>
         public void Place(Vector2I cell, RpgDirection facing)
         {

src/World/RpgAutotileLayer.cs

@@ -0,0 +1,50 @@
+using System.Collections.Generic;
+using Godot;
+
+namespace Cthangover.Mods.Rpg
+{
+    /// <summary>
+    /// The autotile cells of one map layer, drawn as a child of that layer's
+    /// <see cref="TileMapLayer"/> — right above its plain tiles, below the next layer — with
+    /// the layer's material (the map's light). A tile map cannot hold them: each cell is four
+    /// quarters picked from its neighbours (<see cref="RpgAutotiles"/>), so the cells and their
+    /// quarters are worked out once when the map is built and drawn by <c>_Draw</c>, which
+    /// Godot caches until the next redraw.
+    /// </summary>
+    public partial class RpgAutotileLayer : Node2D
+    {
+        private readonly List<(Rect2 Cell, Texture2D Block, Vector2I[] Quarters)> cells = new();
+        private readonly int tileSize;
+
+        /// <summary>Collects the autotile cells of <paramref name="layer"/>; cells whose picture is missing stay empty.</summary>
+        public RpgAutotileLayer(RpgMapGrid grid, RpgLayer layer, RpgTileset tileset, RpgTextures textures)
+        {
+            Name = layer + "Autotiles";
+            UseParentMaterial = true;
+            tileSize = tileset.TileSize;
+            for (var y = 0; y < grid.Height; y++)
+            {
+                for (var x = 0; x < grid.Width; x++)
+                {
+                    var index = grid.GetTile(layer, x, y);
+                    var info = tileset.AutotileOf(index);
+                    var block = info == null ? null : textures.Tileset(info.Autotile);
+                    if (block == null)
+                        continue;
+                    var rect = new Rect2(x * tileSize, y * tileSize, tileSize, tileSize);
+                    cells.Add((rect, block, RpgAutotiles.QuartersAt(grid, layer, x, y, index)));
+                }
+            }
+        }
+
+        /// <summary>Number of drawn autotile cells.</summary>
+        public int Count => cells.Count;
+
+        /// <summary>Draws every collected cell.</summary>
+        public override void _Draw()
+        {
+            foreach (var (cell, block, quarters) in cells)
+                RpgAutotiles.Draw(this, block, cell, quarters, tileSize, Colors.White);
+        }
+    }
+}

src/World/RpgLighting.cs

@@ -0,0 +1,137 @@
+using System.Collections.Generic;
+using System.Linq;
+using Cthangover.Core.Mods.Resolvers;
+using Cthangover.Core.Settings;
+using Cthangover.Mods.Time;
+using Godot;
+
+namespace Cthangover.Mods.Rpg
+{
+    /// <summary>
+    /// Light of a mounted map. One <c>rpg_lit</c> material is shared by the tile layers and
+    /// every actor (their sprites use the parent's material), so the whole map is lit by the
+    /// same ambient and the same lights.
+    /// <para/>
+    /// The ambient follows the game clock with the phases and cross-fades of the novel
+    /// backgrounds (<see cref="UiLightController.CalculateTimeWeights"/>; dark mode forces night,
+    /// the light switch off keeps day), unless the map fixes its own (<see cref="RpgMap.Ambient"/>,
+    /// a lit room). The lights are the player's own glow, the tiles whose tileset entry has a
+    /// <see cref="RpgLight"/> (lamps and windows light every map they are drawn on, collected
+    /// once per map) and the shown events with a light on their active page. The nearest to the
+    /// player win, at most <see cref="MaxLights"/>. They are pushed every frame in canvas
+    /// pixels, because the view moves with the player and actors walk.
+    /// </summary>
+    public sealed class RpgLighting
+    {
+        /// <summary>Lights the shader takes (its arrays' size).</summary>
+        public const int MaxLights = 16;
+
+        /// <summary>Reach of the player's glow in cells.</summary>
+        public const float PlayerRadius = 3.5f;
+
+        private static readonly Color PlayerColor = new(1f, 0.9f, 0.75f, 0.75f);
+        private static readonly Vector4 Day = new(0, 1, 0, 0);
+        private static readonly Vector4 Night = new(0, 0, 0, 1);
+
+        private readonly Vector2[] positions = new Vector2[MaxLights];
+        private readonly Color[] colors = new Color[MaxLights];
+        private readonly float[] radii = new float[MaxLights];
+        private readonly List<(Vector2I Cell, RpgLight Light)> tileLights = new();
+        private readonly List<(Vector2 Centre, RpgLight Light)> candidates = new();
+
+        /// <summary>The shared material; null when the shader is missing (the map is drawn unlit).</summary>
+        public ShaderMaterial Material { get; }
+
+        /// <summary>Creates the material for <paramref name="map"/>, applies its fixed ambient and collects the lit tiles.</summary>
+        public RpgLighting(RpgMap map, RpgMapGrid grid, RpgTileset tileset)
+        {
+            if (tileset != null)
+                tileLights.AddRange(TileLights(grid, tileset));
+
+            var shader = Shaders.Resolve("rpg_lit");
+            if (shader == null)
+                return;
+            Material = new ShaderMaterial { Shader = shader };
+            var ambient = !string.IsNullOrEmpty(map.Ambient) && Color.HtmlIsValid(map.Ambient);
+            Material.SetShaderParameter("use_ambient", ambient);
+            if (ambient)
+                Material.SetShaderParameter("ambient_color", Color.FromHtml(map.Ambient));
+        }
+
+        /// <summary>
+        /// The ambient weights for an hour 0–24: night in dark mode, day while lighting is
+        /// switched off, otherwise the phase blend of the time shaders.
+        /// </summary>
+        public static Vector4 Weights(float hour, bool darkMode, bool useLight)
+        {
+            if (darkMode)
+                return Night;
+            if (!useLight)
+                return Day;
+            return UiLightController.CalculateTimeWeights(hour);
+        }
+
+        /// <summary>Cells of <paramref name="grid"/> whose tile (on any layer) gives off light, with that light.</summary>
+        public static List<(Vector2I Cell, RpgLight Light)> TileLights(RpgMapGrid grid, RpgTileset tileset)
+        {
+            var result = new List<(Vector2I, RpgLight)>();
+            for (var y = 0; y < grid.Height; y++)
+            {
+                for (var x = 0; x < grid.Width; x++)
+                {
+                    foreach (var layer in new[] { RpgLayer.Back, RpgLayer.Main, RpgLayer.Front })
+                    {
+                        var light = tileset.LightOf(grid.GetTile(layer, x, y));
+                        if (light == null)
+                            continue;
+                        result.Add((new Vector2I(x, y), light));
+                        break;
+                    }
+                }
+            }
+            return result;
+        }
+
+        /// <summary>Pushes the ambient of the current hour and the lights of <paramref name="view"/>.</summary>
+        public void Update(RpgWorldView view, IEnumerable<RpgActor> events)
+        {
+            if (Material == null || view.Player == null)
+                return;
+
+            var controller = UiLightController.Instance;
+            var hour = GameData.Instance?.Runtime?.Time?.Normalized ?? 12f;
+            Material.SetShaderParameter("time_weights", Weights(hour, controller?.IsDarkMode == true, controller?.IsUseLight != false));
+
+            var half = new Vector2(view.TileSize, view.TileSize) / 2f;
+            candidates.Clear();
+            foreach (var (cell, light) in tileLights)
+                candidates.Add((new Vector2(cell.X, cell.Y) * view.TileSize + half, light));
+            foreach (var actor in events)
+            {
+                if (actor.Visible && actor.Current?.Light != null)
+                    candidates.Add((actor.Position + half, actor.Current.Light));
+            }
+
+            var cellPixels = view.TileSize * view.GlobalScale.X;
+            var player = view.Player.Position + half;
+            positions[0] = view.ToGlobal(player);
+            colors[0] = PlayerColor;
+            radii[0] = PlayerRadius * cellPixels;
+            var count = 1;
+            foreach (var (centre, light) in candidates.OrderBy(c => c.Centre.DistanceSquaredTo(player)))
+            {
+                if (count >= MaxLights)
+                    break;
+                positions[count] = view.ToGlobal(centre);
+                colors[count] = Color.HtmlIsValid(light.Color ?? "") ? Color.FromHtml(light.Color) : Colors.White;
+                radii[count] = light.Radius * cellPixels;
+                count++;
+            }
+
+            Material.SetShaderParameter("light_count", count);
+            Material.SetShaderParameter("light_positions", positions);
+            Material.SetShaderParameter("light_colors", colors);
+            Material.SetShaderParameter("light_radii", radii);
+        }
+    }
+}

src/World/RpgTextures.cs

@@ -8,7 +8,8 @@ namespace Cthangover.Mods.Rpg
     /// Image lookup of the RPG world: tileset atlases in the <c>tilesets</c> file
     /// group, charsets in <c>charsets</c>. Both are file groups (last mod wins),
     /// not texture groups, so their names never collide with backgrounds or
-    /// icons. Decoded textures are kept for the life of one world, which builds
+    /// icons; item pictures for <see cref="RpgMapEvent.Icon"/> come from the
+    /// <c>items</c> group the inventory uses. Decoded textures are kept for the life of one world, which builds
     /// and owns an instance; the editor keeps its own.
     /// </summary>
     public class RpgTextures
@@ -19,6 +20,9 @@ namespace Cthangover.Mods.Rpg
         /// <summary>File group of charset images.</summary>
         public const string CharsetGroup = "charsets";
 
+        /// <summary>File group of item pictures (an item's <c>Sprite</c>).</summary>
+        public const string IconGroup = "items";
+
         private readonly Dictionary<string, Texture2D> cache = new();
 
         /// <summary>Tileset atlas image, or null (logged by the loader).</summary>
@@ -27,6 +31,9 @@ namespace Cthangover.Mods.Rpg
         /// <summary>Charset image, or null.</summary>
         public Texture2D Charset(string path) => Load(CharsetGroup, path);
 
+        /// <summary>Item picture, or null.</summary>
+        public Texture2D Icon(string path) => Load(IconGroup, path);
+
         private Texture2D Load(string group, string path)
         {
             if (string.IsNullOrWhiteSpace(path))

src/World/RpgWorldView.cs

@@ -12,7 +12,8 @@ namespace Cthangover.Mods.Rpg
     /// scene is entered and freed when the scene is left.
     /// <para/>
     /// Draw order (children, bottom to top): back tiles, main tiles, the actor
-    /// layer (Y-sorted: events and the player), front tiles. The whole node is
+    /// layer (Y-sorted: events and the player), front tiles; each tile layer draws its
+    /// autotile cells over its plain tiles (<see cref="RpgAutotileLayer"/>). The whole node is
     /// scaled by the map's zoom with nearest filtering and follows the player
     /// like a camera, clamped to the map edges; a map smaller than the screen is
     /// centred.
@@ -23,6 +24,9 @@ namespace Cthangover.Mods.Rpg
     /// event on the cell fires, else the encounter table rolls. The action key
     /// fires the action event in front of the player (or under them); during a
     /// dialog it advances the dialog instead.
+    /// <para/>
+    /// Layers and actors share the material of <see cref="RpgLighting"/> (time of day, the
+    /// player's glow, lit events), updated after the camera each frame.
     /// </summary>
     public partial class RpgWorldView : Node2D
     {
@@ -32,6 +36,7 @@ namespace Cthangover.Mods.Rpg
         private RpgMapGrid grid;
         private Node2D actorLayer;
         private Texture2D atlas;
+        private RpgLighting lighting;
 
         /// <summary>The mounted map.</summary>
         public RpgMap Map { get; private set; }
@@ -59,6 +64,7 @@ namespace Cthangover.Mods.Rpg
                 GameLogger.Log("RPG", $"map '{map.ID}': tileset '{map.Tileset}' not found", LogLevel.Error);
             atlas = Tileset != null ? textures.Tileset(Tileset.Image) : null;
             var tileSet = Tileset != null && atlas != null ? RpgTileSetBuilder.Build(Tileset, atlas) : null;
+            lighting = new RpgLighting(map, grid, Tileset);
 
             AddChild(BuildLayer(RpgLayer.Back, tileSet));
             AddChild(BuildLayer(RpgLayer.Main, tileSet));
@@ -66,11 +72,11 @@ namespace Cthangover.Mods.Rpg
             AddChild(actorLayer);
             AddChild(BuildLayer(RpgLayer.Front, tileSet));
 
-            foreach (var mapEvent in map.Events ?? new List<RpgMapEvent>())
+            foreach (var mapEvent in RpgMapEvents.Of(map.ID))
                 AddEventActor(mapEvent);
             RefreshEvents();
 
-            Player = new RpgActor(TileSize) { Name = "Player" };
+            Player = new RpgActor(TileSize) { Name = "Player", Material = lighting.Material };
             Player.UseCharset(textures.Charset(RpgPlayerLook.Charset()));
             Player.StepFinished += OnPlayerStepFinished;
             actorLayer.AddChild(Player);
@@ -92,7 +98,22 @@ namespace Cthangover.Mods.Rpg
         public void RefreshEvents()
         {
             foreach (var actor in eventActors.Values)
-                actor.Visible = string.IsNullOrWhiteSpace(actor.Event.Condition) || ScenarioCondition.Evaluate(actor.Event.Condition);
+            {
+                var index = RpgEventPages.ActiveIndex(actor.Event, ScenarioCondition.Evaluate);
+                actor.Visible = index >= 0;
+                if (index < 0 || index == actor.PageIndex)
+                    continue;
+                var first = actor.PageIndex == -2;
+                actor.PageIndex = index;
+                actor.Current = RpgEventPages.Effective(actor.Event, index);
+                actor.RouteIndex = 0;
+                actor.RouteTimer = actor.Current.Route?.Every ?? 0;
+                ApplyLook(actor);
+                if (first)
+                    actor.Place(new Vector2I(actor.Event.X, actor.Event.Y), actor.Current.Dir);
+                else if (index > 0 && actor.Event.Pages[index - 1].Dir.HasValue)
+                    actor.Face(actor.Current.Dir);
+            }
         }
 
         /// <summary>True when the cell lies on the map (a saved position may be stale after a map edit).</summary>
@@ -105,7 +126,7 @@ namespace Cthangover.Mods.Rpg
                 return false;
             foreach (var actor in eventActors.Values)
             {
-                if (actor.Visible && actor.Event.IsSolid && actor.Cell == cell)
+                if (actor.Visible && actor.Current?.IsSolid == true && actor.Cell == cell)
                     return false;
             }
             return true;
@@ -119,7 +140,7 @@ namespace Cthangover.Mods.Rpg
         {
             foreach (var actor in eventActors.Values)
             {
-                if (actor.Visible && actor.Cell == cell && actor.Event.Trigger == trigger)
+                if (actor.Visible && actor.Cell == cell && actor.Current?.Trigger == trigger)
                     return actor;
             }
             return null;
@@ -141,13 +162,16 @@ namespace Cthangover.Mods.Rpg
 
             if (target.Cell != Player.Cell)
                 target.Face(RpgDirections.Opposite(Player.Facing));
-            return RpgEventRunner.Run(target.Event, Map.ID);
+            return RpgEventRunner.Run(target.Current, Map.ID);
         }
 
         /// <summary>Walking: one decision per frame while the player stands still.</summary>
         public override void _Process(double delta)
         {
-            if (Player != null && !Player.IsMoving && !RpgInput.IsWalkBlocked(this))
+            var blocked = RpgInput.IsWalkBlocked(this);
+            if (!blocked)
+                WalkRoutes(delta);
+            if (Player != null && !Player.IsMoving && !blocked)
             {
                 var held = RpgInput.HeldDirection();
                 if (held.HasValue)
@@ -160,6 +184,7 @@ namespace Cthangover.Mods.Rpg
                 }
             }
             UpdateCamera();
+            lighting.Update(this, eventActors.Values);
         }
 
         /// <summary>The action key: advances a running dialog, otherwise interacts.</summary>
@@ -188,7 +213,7 @@ namespace Cthangover.Mods.Rpg
             var touch = EventAt(player.Cell, RpgEventTrigger.Touch);
             if (touch != null)
             {
-                RpgEventRunner.Run(touch.Event, Map.ID);
+                RpgEventRunner.Run(touch.Current, Map.ID);
                 return;
             }
 
@@ -199,7 +224,7 @@ namespace Cthangover.Mods.Rpg
 
         private TileMapLayer BuildLayer(RpgLayer layer, TileSet tileSet)
         {
-            var node = new TileMapLayer { Name = layer.ToString(), TileSet = tileSet };
+            var node = new TileMapLayer { Name = layer.ToString(), TileSet = tileSet, Material = lighting.Material };
             if (tileSet == null)
                 return node;
             for (var y = 0; y < grid.Height; y++)
@@ -207,10 +232,15 @@ namespace Cthangover.Mods.Rpg
                 for (var x = 0; x < grid.Width; x++)
                 {
                     var index = grid.GetTile(layer, x, y);
-                    if (index >= 0)
+                    if (index >= 0 && Tileset.AutotileOf(index) == null)
                         node.SetCell(new Vector2I(x, y), RpgTileSetBuilder.SourceId, RpgTileSetBuilder.AtlasCoords(Tileset, index));
                 }
             }
+            var autotiles = new RpgAutotileLayer(grid, layer, Tileset, textures);
+            if (autotiles.Count > 0)
+                node.AddChild(autotiles);
+            else
+                autotiles.Free();
             return node;
         }
 
@@ -222,16 +252,58 @@ namespace Cthangover.Mods.Rpg
                 return;
             }
 
-            var actor = new RpgActor(TileSize, mapEvent) { Name = "Event_" + mapEvent.Id };
-            if (!string.IsNullOrEmpty(mapEvent.Sprite))
-                actor.UseCharset(textures.Charset(mapEvent.Sprite));
-            else if (mapEvent.Tile >= 0 && Tileset != null)
-                actor.UseTile(atlas, RpgTileSetBuilder.AtlasCoords(Tileset, mapEvent.Tile));
-            actor.Place(new Vector2I(mapEvent.X, mapEvent.Y), mapEvent.Dir);
+            // The look and the cell come with the first page (RefreshEvents).
+            var actor = new RpgActor(TileSize, mapEvent) { Name = "Event_" + mapEvent.Id, Material = lighting.Material };
             actorLayer.AddChild(actor);
             eventActors[mapEvent.Id] = actor;
         }
 
+        /// <summary>Shows the active page's charset, tile or icon (nothing for an invisible trigger).</summary>
+        private void ApplyLook(RpgActor actor)
+        {
+            var page = actor.Current;
+            actor.ClearLook();
+            if (!string.IsNullOrEmpty(page.Sprite))
+                actor.UseCharset(textures.Charset(page.Sprite));
+            else if (page.Tile >= 0 && Tileset != null)
+                actor.UseTile(atlas, RpgTileSetBuilder.AtlasCoords(Tileset, page.Tile));
+            else if (!string.IsNullOrEmpty(page.Icon))
+                actor.UseIcon(textures.Icon(page.Icon));
+        }
+
+        /// <summary>
+        /// Advances the routes of the shown events (<see cref="RpgMoveRoute"/>): one step per
+        /// <c>Every</c> seconds; a walk into a blocked cell or onto the player only turns.
+        /// </summary>
+        private void WalkRoutes(double delta)
+        {
+            foreach (var actor in eventActors.Values)
+            {
+                var route = actor.Current?.Route;
+                if (!actor.Visible || route?.Steps == null || route.Steps.Count == 0 || actor.IsMoving)
+                    continue;
+                actor.RouteTimer -= delta;
+                if (actor.RouteTimer > 0)
+                    continue;
+                actor.RouteTimer = Math.Max(0.1, route.Every);
+                if (actor.RouteIndex >= route.Steps.Count)
+                {
+                    if (!route.Repeat)
+                        continue;
+                    actor.RouteIndex = 0;
+                }
+
+                var step = RpgRouteStep.Resolve(route.Steps[actor.RouteIndex++], actor.Cell, Player?.Cell ?? actor.Cell, random);
+                if (!step.Direction.HasValue)
+                    continue;
+                var next = actor.Cell + RpgDirections.Delta(step.Direction.Value);
+                if (step.Moves && CanEnter(next) && next != Player?.Cell)
+                    actor.StepTo(step.Direction.Value);
+                else
+                    actor.Face(step.Direction.Value);
+            }
+        }
+
         private void UpdateCamera()
         {
             if (Player == null || GetParent() is not Control host)

test_suites/walk/manifest.json

@@ -1,6 +1,6 @@
 {
   "name": "RPG Walk Test",
-  "description": "Integration test of the rpg mod on the rpg_demo game: real WASD/E key events walk the hero, collide, read a sign, turn an NPC, go through a door teleport, flip events by a story flag, fight a battle that returns to the same cell with the win flag set. Activated by --itest=rpg_walk with --game=rpg_demo --new; --shots=<dir> saves screenshots (windowed runs only).",
+  "description": "Integration test of the rpg mod on the rpg_plus game (its rpg_demo_game world): real WASD/E key events walk the hero, collide, read a sign, turn an NPC, go through a door teleport, flip events by a story flag, fight a battle that returns to the same cell with the win flag set. A pickup the suite adds to the village through its own map_events file is picked up and must stay gone after leaving the map and coming back, and after a save is loaded. Activated by --itest=rpg_walk with --game=rpg_plus --new (the prologue is clicked through first); --shots=<dir> saves screenshots (windowed runs only).",
   "sources": [
     "src/*.cs"
   ],

test_suites/walk/map_events/rpg_village/rpg_walk_test.json

@@ -0,0 +1,19 @@
+{
+  "Events": [
+    {
+      "Id": "rpg_walk_mushroom",
+      "X": 18,
+      "Y": 14,
+      "Icon": "rpg_demo/forest_mushroom",
+      "Trigger": "Touch",
+      "Solid": false,
+      "Commands": [
+        "ptext \"Found: a mushroom\"",
+        "action item.add id=rpg_demo/mushroom count=1",
+        "flag rpg_village_rpg_walk_mushroom_taken 1",
+        "end"
+      ],
+      "Condition": "rpg_village_rpg_walk_mushroom_taken != 1"
+    }
+  ]
+}

test_suites/walk/src/RpgWalkTestDriver.cs

@@ -6,6 +6,7 @@ using Cthangover.Core.Factories.Impls;
 using Cthangover.Core.Games;
 using Cthangover.Core.Scenes;
 using Cthangover.Core.Settings;
+using Cthangover.Core.Items;
 using Cthangover.Core.Utils;
 using Cthangover.Mods.Interface.View;
 using Godot;
@@ -17,6 +18,13 @@ namespace Cthangover.Mods.Rpg.Tests
     /// <see cref="Input.ParseInputEvent"/>, so the world reads them exactly as
     /// it reads a keyboard (physical keys, held state, unhandled action key).
     /// <para/>
+    /// A pickup is checked across map rebuilds: the suite's own
+    /// <c>map_events/rpg_village/rpg_walk_test.json</c> lays a mushroom on the demo's
+    /// village (an event added by another mod, shaped like the map editor's
+    /// pickups); it is picked up, the player leaves the map and comes back, then
+    /// saves, loads and comes back again — it must never reappear nor give a
+    /// second item.
+    /// <para/>
     /// One step per timer tick; a step either waits (returns without
     /// advancing) or checks and moves on. A failed check is recorded and the
     /// run goes on; an exception ends it. Result line:
@@ -26,17 +34,26 @@ namespace Cthangover.Mods.Rpg.Tests
     public partial class RpgWalkTestDriver : Node
     {
         private const float TickSeconds = 0.1f;
+
+        // The battle opens with an intro animation (the backdrop zooms in): shots wait it out.
+        private const int BattleIntroTicks = 20;
         private const float TimeoutSeconds = 90f;
         private const string Village = "rpg_village";
         private const string House = "rpg_elder_house";
         private const string WinFlag = "rpg_test_win";
         private const string SaveSlot = "slot_9901";
+        private const string PickupId = "rpg_walk_mushroom";
+        private const string PickupFlag = "rpg_village_rpg_walk_mushroom_taken";
+        private const string Mushroom = "rpg_demo/mushroom";
+
+        private static readonly Vector2I PickupCell = new(18, 14);
 
         private readonly string shotsDir;
         private readonly List<string> failures = new();
         private int passed;
         private int step;
         private int waitTicks;
+        private int mushroomsBefore;
         private double elapsed;
 
         /// <summary>Creates the driver; <paramref name="shotsDir"/> null disables screenshots.</summary>
@@ -51,6 +68,10 @@ namespace Cthangover.Mods.Rpg.Tests
 
         private static RpgWorldView View => RpgWorldHost.Current?.View;
 
+        private static IInventory Inventory => GameData.Instance.Runtime.Inventory;
+
+        private static string Flag(string name) => GameData.Instance.Runtime.Flags.TryGetValue(name, out var value) ? value : null;
+
         private void Tick()
         {
             if (step < 0)
@@ -79,6 +100,8 @@ namespace Cthangover.Mods.Rpg.Tests
             switch (step)
             {
                 case 0:
+                    if (Boot.IsReady && SkipPrologue())
+                        return;
                     if (Boot.IsReady && View?.Map?.ID == Village)
                         Next();
                     return;
@@ -142,17 +165,63 @@ namespace Cthangover.Mods.Rpg.Tests
                 case 9:
                     if (AdvanceDialog())
                         return;
+                    // A pickup this suite adds to the demo's village (map_events of another mod).
+                    mushroomsBefore = Inventory.CheckCount(Mushroom);
+                    Check(View.FindEvent(PickupId)?.Visible == true, "a test mod's map_events file adds a pickup to the demo's village");
+                    View.PlacePlayer(PickupCell.X - 1, PickupCell.Y, RpgDirection.Right);
+                    Press(Key.D, true);
+                    Next();
+                    return;
+                case 10:
+                    if (View.Player.Cell.X < PickupCell.X)
+                        return;
+                    Press(Key.D, false);
+                    Next();
+                    return;
+                case 11:
+                    // Stepping on the pickup starts its dialog; the flag is set when it ends.
+                    if (AdvanceDialog() || Flag(PickupFlag) != "1")
+                        return;
+                    Check(Inventory.CheckCount(Mushroom) == mushroomsBefore + 1, $"stepping on the pickup adds the item, {Inventory.CheckCount(Mushroom)} now");
+                    Check(View.FindEvent(PickupId)?.Visible == false, "the picked item leaves the map");
+                    RpgWorldHost.Teleport(new RpgTeleport { Map = House, X = 6, Y = 8, Dir = RpgDirection.Up });
+                    Next();
+                    return;
+                case 12:
+                    if (View?.Map?.ID != House || GodotSceneService.IsTransitioning || AdvanceDialog())
+                        return;
+                    RpgWorldHost.Teleport(new RpgTeleport { Map = Village, X = PickupCell.X - 1, Y = PickupCell.Y, Dir = RpgDirection.Right });
+                    Next();
+                    return;
+                case 13:
+                    if (View?.Map?.ID != Village || GodotSceneService.IsTransitioning || AdvanceDialog())
+                        return;
+                    CheckPickupGone("after leaving the map and coming back");
+                    Press(Key.D, true);
+                    Next();
+                    return;
+                case 14:
+                    if (View.Player.Cell.X < PickupCell.X)
+                        return;
+                    Press(Key.D, false);
+                    Next();
+                    return;
+                case 15:
+                    if (View.Player.IsMoving || ++waitTicks < 5)
+                        return;
+                    Check(RpgInput.FindDialogBox()?.IsRunning != true && Inventory.CheckCount(Mushroom) == mushroomsBefore + 1,
+                        "stepping on the empty cell again gives nothing");
                     View.PlacePlayer(6, 7, RpgDirection.Up);
                     Press(Key.W, true);
                     Next();
                     return;
-                case 10:
+                case 16:
                     if (!View.Player.IsMoving && View.Map.ID == Village)
                         return;
                     Press(Key.W, false);
                     Next();
                     return;
-                case 11:
+                case 17:
                     if (View?.Map?.ID != House)
                         return;
                     if (AdvanceDialog())
@@ -163,35 +232,35 @@ namespace Cthangover.Mods.Rpg.Tests
                     ScenarioCondition.SetFlag("rpg_wolf_dead", "1");
                     Next();
                     return;
-                case 12:
+                case 18:
                     Check(View.FindEvent("elder_quest")?.Visible == false && View.FindEvent("elder_thanks")?.Visible == true, "a story flag swaps the elder's events at once");
                     ScenarioCondition.SetFlag("rpg_wolf_dead", "0");
                     Check(RpgBattleService.Start("rpg_slime", WinFlag), "a battle starts from the map");
                     Godot.Engine.TimeScale = 4;
                     Next();
                     return;
-                case 13:
+                case 19:
                     if (GetTree().CurrentScene is not BattleSceneContext battle)
                         return;
                     // The core's auto turn only passes, so the hero would lose: once the
                     // core waits for the player, take the platform's victory path.
                     if (battle.ActiveBattleCore is not IBattleAutoPlayable auto || !auto.IsWaitingForPlayerInput)
                         return;
-                    // The shot waits for the fade-in too, otherwise it catches the blank transition.
-                    if (GodotSceneService.IsTransitioning)
+                    // The shot waits for the fade-in and the intro animation, otherwise it catches the zoomed backdrop.
+                    if (GodotSceneService.IsTransitioning || ++waitTicks < BattleIntroTicks)
                         return;
                     Shot("battle");
                     battle.ShowWinground();
                     Next();
                     return;
-                case 14:
+                case 20:
                     if (GetTree().Root.FindChild("ContinueButton", true, false) is not Button button || !button.IsVisibleInTree())
                         return;
                     Shot("victory");
                     button.EmitSignal(BaseButton.SignalName.Pressed);
                     Next();
                     return;
-                case 15:
+                case 21:
                     if (View?.Map?.ID != House || GodotSceneService.IsTransitioning)
                         return;
                     Godot.Engine.TimeScale = 1;
@@ -202,19 +271,27 @@ namespace Cthangover.Mods.Rpg.Tests
                     GameSession.OpenMainMenu(GetTree());
                     Next();
                     return;
-                case 16:
+                case 22:
                     if (RpgWorldHost.Current != null || ++waitTicks < 5)
                         return;
                     Check(GameSession.LoadAndEnter(this, SaveSlot), "the save loads");
                     Next();
                     return;
-                case 17:
+                case 23:
                     if (View?.Map?.ID != House || GodotSceneService.IsTransitioning || ++waitTicks < 5)
                         return;
                     Shot("loaded");
                     var dialog = RpgInput.FindDialogBox();
                     Check(dialog != null && !dialog.IsRunning && !dialog.IsVisibleInTree(), $"no dialog box after loading (running={dialog?.IsRunning}, visible={dialog?.IsVisibleInTree()})");
                     Check(View.Player.Cell == new Vector2I(6, 8), $"the loaded game puts the player on the saved cell, got {View.Player.Cell}");
+                    Check(Flag(PickupFlag) == "1" && Inventory.CheckCount(Mushroom) == mushroomsBefore + 1, "the save keeps the pickup's flag and the picked item");
+                    RpgWorldHost.Teleport(new RpgTeleport { Map = Village, X = PickupCell.X - 1, Y = PickupCell.Y, Dir = RpgDirection.Right });
+                    Next();
+                    return;
+                case 24:
+                    if (View?.Map?.ID != Village || GodotSceneService.IsTransitioning || AdvanceDialog())
+                        return;
+                    CheckPickupGone("after loading the save");
                     SaveService.DeleteSave(SaveSlot);
                     Finish();
                     return;
@@ -237,7 +314,36 @@ namespace Cthangover.Mods.Rpg.Tests
             }
         }
 
+        /// <summary>The map was built again (a teleport or a load): the picked item must stay gone and give nothing.</summary>
+        private void CheckPickupGone(string when)
+        {
+            var pickup = View.FindEvent(PickupId);
+            Check(pickup != null && !pickup.Visible, $"the picked item does not come back {when}");
+            Check(View.EventAt(PickupCell, RpgEventTrigger.Touch) == null, $"its cell has no pickup to step on {when}");
+            Check(Inventory.CheckCount(Mushroom) == mushroomsBefore + 1, $"the inventory still holds exactly the one picked item {when}");
+        }
+
         /// <summary>Advances a running dialog with the action key; true while it is still running.</summary>
+        /// <summary>
+        /// The game opens with a novel-style prologue (no map yet): its lines are clicked
+        /// through and every choice takes the first answer. True while it runs.
+        /// </summary>
+        private static bool SkipPrologue()
+        {
+            // Asking for the dialog box before the first scene is up caches the wrong node.
+            var scene = ((SceneTree)Engine.GetMainLoop()).Root.GetNodeOrNull<SceneManager>("SceneManager")?.CurrentSceneName;
+            if (string.IsNullOrEmpty(scene) || RpgWorldHost.Current?.View?.Map != null)
+                return false;
+            var box = RpgInput.FindDialogBox();
+            if (box == null || !box.IsRunning)
+                return false;
+            if (box.IsWaitingAnswer)
+                box.TrySelectVariant(0);
+            else
+                box.NextAction();
+            return true;
+        }
+
         private bool AdvanceDialog()
         {
             var box = RpgInput.FindDialogBox();

test_suites/walk/src/RpgWalkTestInitializer.cs

@@ -32,7 +32,7 @@ namespace Cthangover.Mods.Rpg.Tests
                 .Select(a => a.Substring("--shots=".Length))
                 .FirstOrDefault();
             GameLogger.Log("TEST", $"RpgWalkTestInitializer: activating rpg_walk, shots={shots ?? "off"}");
-            (Godot.Engine.GetMainLoop() as SceneTree)?.Root?.CallDeferred("add_child", new RpgWalkTestDriver(shots));
+            ModRoot.AddDeferred(new RpgWalkTestDriver(shots));
         }
     }
 }

tests/RpgAutotilesTests.cs

@@ -0,0 +1,64 @@
+namespace Cthangover.Mods.Rpg.Tests
+{
+    using Cthangover.Core.Mods.Testing;
+    using Godot;
+
+    /// <summary>Autotile cells are assembled from quarters of the A2 block picked by their neighbours.</summary>
+    public class RpgAutotilesTests
+    {
+        private const int Water = 40;
+
+        private static bool Is(Vector2I[] quarters, params int[] xy)
+        {
+            for (var i = 0; i < 4; i++)
+            {
+                if (quarters[i] != new Vector2I(xy[i * 2], xy[i * 2 + 1]))
+                    return false;
+            }
+            return true;
+        }
+
+        [ModTest("autotiles/quarters_by_neighbours")]
+        static void QuartersByNeighbours(ModTestContext ctx)
+        {
+            ModAssert.True(Is(RpgAutotiles.Quarters(false, false, false, false, false, false, false, false), 0, 2, 3, 2, 0, 5, 3, 5),
+                "alone: the four outer corners");
+            ModAssert.True(Is(RpgAutotiles.Quarters(true, true, true, true, true, true, true, true), 2, 4, 1, 4, 2, 3, 1, 3),
+                "surrounded: the fill of the patch");
+            ModAssert.True(Is(RpgAutotiles.Quarters(true, true, true, true, false, false, false, false), 2, 0, 3, 0, 2, 1, 3, 1),
+                "sides alike, corners not: the inner corners");
+            ModAssert.True(Is(RpgAutotiles.Quarters(false, true, true, true, false, false, true, true), 2, 2, 1, 2, 2, 3, 1, 3),
+                "the top row of a pond: top edge above, fill below");
+            ModAssert.True(Is(RpgAutotiles.Quarters(true, true, false, true, false, true, false, true), 0, 4, 1, 4, 0, 3, 1, 3),
+                "the left column: left edge");
+            var corner = RpgAutotiles.Quarters(true, true, true, true, false, true, true, true);
+            ModAssert.True(corner[0] == new Vector2I(2, 0) && corner[3] == new Vector2I(1, 3), "only the missing corner turns inner");
+        }
+
+        [ModTest("autotiles/cells_read_their_layer_and_the_map_edge_counts_alike")]
+        static void QuartersAt(ModTestContext ctx)
+        {
+            var grid = new RpgMapGrid(3, 3);
+            grid.SetTile(RpgLayer.Back, 0, 0, Water);
+            grid.SetTile(RpgLayer.Back, 1, 0, Water);
+            grid.SetTile(RpgLayer.Main, 0, 1, Water);
+
+            var corner = RpgAutotiles.QuartersAt(grid, RpgLayer.Back, 0, 0, Water);
+            ModAssert.True(corner[0] == new Vector2I(2, 4), "off the map counts as water: the top-left quarter is fill");
+            ModAssert.True(corner[2] == new Vector2I(2, 5), "below lies grass on this layer: bottom edge (the main layer is not read)");
+            ModAssert.True(corner[1] == new Vector2I(1, 4), "to the right is water");
+
+            var end = RpgAutotiles.QuartersAt(grid, RpgLayer.Back, 1, 0, Water);
+            ModAssert.True(end[1] == new Vector2I(3, 4), "the right end: right edge");
+            ModAssert.True(end[3] == new Vector2I(3, 5), "and its outer bottom-right corner");
+        }
+
+        [ModTest("autotiles/source_and_preview_rects")]
+        static void Rects(ModTestContext ctx)
+        {
+            ModAssert.True(RpgAutotiles.SourceRect(new Vector2I(3, 5), 32) == new Rect2(48, 80, 16, 16), "quarters are half tiles");
+            ModAssert.True(RpgAutotiles.SourceRect(Vector2I.Zero, 48) == new Rect2(0, 0, 24, 24), "of any tile size");
+            ModAssert.True(RpgAutotiles.PreviewRect(32) == new Rect2(0, 0, 32, 32), "the preview is the top-left tile");
+        }
+    }
+}

tests/RpgEventPagesTests.cs

@@ -0,0 +1,113 @@
+namespace Cthangover.Mods.Rpg.Tests
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Text.Json;
+    using Cthangover.Core.Mods.Testing;
+    using Cthangover.Core.Utils;
+    using Godot;
+
+    /// <summary>Event pages pick the last page whose condition holds; routes resolve their steps; a page light replaces the event's.</summary>
+    public class RpgEventPagesTests
+    {
+        private static RpgMapEvent Chest() => JsonSerializer.Deserialize<RpgMapEvent>(@"{
+            ""Id"": ""chest"", ""X"": 3, ""Y"": 2, ""Tile"": 40, ""Commands"": [""flag chest_open 1""],
+            ""Pages"": [
+              { ""Condition"": ""chest_open == 1"", ""Icon"": ""rpg_demo/coin"", ""Commands"": [""text \""Empty.\""""] },
+              { ""Condition"": ""guard_back == 1"", ""Sprite"": ""village/guard"", ""Dir"": ""left"", ""Solid"": true }
+            ]
+        }", JsonOptionsProvider.ReadOptions);
+
+        private static Func<string, bool> Flags(params string[] holding) => c => Array.IndexOf(holding, c) >= 0;
+
+        [ModTest("pages/last_holding_page_wins")]
+        static void LastHoldingPageWins(ModTestContext ctx)
+        {
+            var chest = Chest();
+            ModAssert.Equal(0, RpgEventPages.ActiveIndex(chest, Flags()), "no page holds: the event itself");
+            ModAssert.Equal(1, RpgEventPages.ActiveIndex(chest, Flags("chest_open == 1")), "the opened page");
+            ModAssert.Equal(2, RpgEventPages.ActiveIndex(chest, Flags("chest_open == 1", "guard_back == 1")), "the later page wins");
+        }
+
+        [ModTest("pages/own_condition_only_turns_off_page_zero")]
+        static void OwnConditionOnlyTurnsOffPageZero(ModTestContext ctx)
+        {
+            var chest = Chest();
+            chest.Condition = "chest_here == 1";
+            ModAssert.Equal(-1, RpgEventPages.ActiveIndex(chest, Flags()), "nothing holds: hidden");
+            ModAssert.Equal(1, RpgEventPages.ActiveIndex(chest, Flags("chest_open == 1")), "a page shows it without the own condition");
+            ModAssert.Equal(0, RpgEventPages.ActiveIndex(new RpgMapEvent { Id = "plain" }, Flags()), "an event without pages and condition");
+        }
+
+        [ModTest("pages/effective_merges_page_over_event")]
+        static void EffectiveMergesPageOverEvent(ModTestContext ctx)
+        {
+            var chest = Chest();
+            ModAssert.True(ReferenceEquals(chest, RpgEventPages.Effective(chest, 0)), "page 0 is the event itself");
+
+            var open = RpgEventPages.Effective(chest, 1);
+            ModAssert.Equal("chest", open.Id, "id kept");
+            ModAssert.Equal(3, open.X, "cell kept");
+            ModAssert.Equal("rpg_demo/coin", open.Icon, "the page's icon");
+            ModAssert.Equal(-1, open.Tile, "a page look replaces the whole look");
+            ModAssert.Equal("text \"Empty.\"", open.Commands[0], "the page's commands");
+            ModAssert.True(open.Trigger == RpgEventTrigger.Action, "trigger inherited");
+
+            var guard = RpgEventPages.Effective(chest, 2);
+            ModAssert.Equal("village/guard", guard.Sprite, "charset of page 2");
+            ModAssert.True(guard.Dir == RpgDirection.Left, "facing of page 2");
+            ModAssert.True(guard.IsSolid, "solid");
+            ModAssert.Equal("flag chest_open 1", guard.Commands[0], "commands inherited from the event");
+            ModAssert.Null(RpgEventPages.Effective(chest, 3), "out of range");
+        }
+
+        [ModTest("routes/steps_resolve")]
+        static void StepsResolve(ModTestContext ctx)
+        {
+            var self = new Vector2I(5, 5);
+            var player = new Vector2I(2, 6);
+            var left = RpgRouteStep.Resolve("Left", self, player, null);
+            ModAssert.True(left.Moves && left.Direction == RpgDirection.Left, "a walk, any case");
+            var face = RpgRouteStep.Resolve("face_up", self, player, null);
+            ModAssert.True(!face.Moves && face.Direction == RpgDirection.Up, "a turn");
+            ModAssert.Null(RpgRouteStep.Resolve("wait", self, player, null).Direction, "wait stands");
+            ModAssert.Null(RpgRouteStep.Resolve("dance", self, player, null).Direction, "an unknown word stands");
+            ModAssert.True(RpgRouteStep.Resolve("toward", self, player, null).Direction == RpgDirection.Left, "toward along the longer axis");
+            ModAssert.True(RpgRouteStep.Resolve("away", self, player, null).Direction == RpgDirection.Right, "away is the opposite");
+            ModAssert.Null(RpgRouteStep.Toward(self, self), "already there");
+            var random = RpgRouteStep.Resolve("random", self, player, new Random(7));
+            ModAssert.True(random.Moves && random.Direction.HasValue, "random walks somewhere");
+        }
+
+        [ModTest("routes/json_defaults")]
+        static void JsonDefaults(ModTestContext ctx)
+        {
+            var mapEvent = JsonSerializer.Deserialize<RpgMapEvent>(@"{ ""Id"": ""cat"", ""Route"": { ""Steps"": [""random""] } }", JsonOptionsProvider.ReadOptions);
+            ModAssert.CloseTo(1.0, mapEvent.Route.Every, what: "a step a second by default");
+            ModAssert.True(mapEvent.Route.Repeat, "repeats by default");
+            ModAssert.Null(mapEvent.Pages, "no pages");
+        }
+
+        [ModTest("lights/page_light_over_event_light_round_trip")]
+        static void PageLightOverEventLight(ModTestContext ctx)
+        {
+            var lamp = JsonSerializer.Deserialize<RpgMapEvent>(@"{
+                ""Id"": ""lamp"", ""Tile"": 12, ""Light"": { ""Radius"": 2.5, ""Color"": ""#ff8040"" },
+                ""Pages"": [ { ""Condition"": ""lamp_out == 1"", ""Tile"": 13, ""Light"": { ""Radius"": 1 } }, { ""Condition"": ""door == 1"" } ]
+            }", JsonOptionsProvider.ReadOptions);
+            ModAssert.CloseTo(2.5, lamp.Light.Radius, what: "the event's light");
+            ModAssert.Equal("#ff8040", lamp.Light.Color, "the event's colour");
+
+            var dim = RpgEventPages.Effective(lamp, 1);
+            ModAssert.CloseTo(1, dim.Light.Radius, what: "the page's light replaces it");
+            ModAssert.Equal("#ffd8a0", dim.Light.Color, "a page light without a colour is warm by default");
+            ModAssert.CloseTo(2.5, RpgEventPages.Effective(lamp, 2).Light.Radius, what: "a page without a light keeps the event's");
+
+            var again = JsonSerializer.Deserialize<RpgMapEvent>(JsonSerializer.Serialize(lamp), JsonOptionsProvider.ReadOptions);
+            ModAssert.CloseTo(2.5, again.Light.Radius, what: "radius survives the round trip");
+            ModAssert.Equal("#ff8040", again.Light.Color, "colour survives the round trip");
+            ModAssert.CloseTo(1, again.Pages[0].Light.Radius, what: "the page light survives the round trip");
+            ModAssert.Null(JsonSerializer.Deserialize<RpgMapEvent>(@"{ ""Id"": ""dark"" }", JsonOptionsProvider.ReadOptions).Light, "no light by default");
+        }
+    }
+}

tests/RpgLightingTests.cs

@@ -0,0 +1,59 @@
+namespace Cthangover.Mods.Rpg.Tests
+{
+    using System.Collections.Generic;
+    using System.Text.Json;
+    using Cthangover.Core.Mods.Testing;
+    using Cthangover.Core.Utils;
+    using Godot;
+
+    /// <summary>The map's light: ambient weights from the clock, lit tiles, the fixed ambient of a map.</summary>
+    public class RpgLightingTests
+    {
+        [ModTest("lights/weights_follow_clock_dark_mode_and_switch")]
+        static void WeightsFollowClock(ModTestContext ctx)
+        {
+            ModAssert.CloseTo(1, RpgLighting.Weights(13f, false, true).Y, what: "noon is day");
+            ModAssert.CloseTo(1, RpgLighting.Weights(0.5f, false, true).W, what: "midnight is night");
+            ModAssert.CloseTo(1, RpgLighting.Weights(13f, true, true).W, what: "dark mode is night at noon");
+            ModAssert.CloseTo(1, RpgLighting.Weights(0.5f, false, false).Y, what: "lighting switched off keeps day at midnight");
+            var dawn = RpgLighting.Weights(5f, false, true);
+            ModAssert.CloseTo(1, dawn.X + dawn.W, what: "dawn blends night into morning");
+            ModAssert.True(dawn.X > 0 && dawn.W > 0, "both phases at dawn");
+        }
+
+        [ModTest("lights/tile_lights_on_any_layer_once_per_cell")]
+        static void TileLights(ModTestContext ctx)
+        {
+            var tileset = new RpgTileset
+            {
+                ID = "lit",
+                Tiles = new List<RpgTileInfo>
+                {
+                    new() { Index = 3, Light = new RpgLight { Radius = 4 } },
+                    new() { Index = 7, Light = new RpgLight { Radius = 1.5f, Color = "#ffd27a" } },
+                    new() { Index = 9, Solid = true },
+                },
+            };
+            var grid = new RpgMapGrid(4, 3);
+            grid.SetTile(RpgLayer.Front, 1, 0, 3);
+            grid.SetTile(RpgLayer.Main, 2, 2, 7);
+            grid.SetTile(RpgLayer.Back, 2, 2, 3);
+            grid.SetTile(RpgLayer.Main, 0, 1, 9);
+
+            var lights = RpgLighting.TileLights(grid, tileset);
+            ModAssert.Equal(2, lights.Count, "one light per lit cell, unlit tiles give none");
+            ModAssert.True(lights.Exists(l => l.Cell == new Vector2I(1, 0) && Mathf.IsEqualApprox(l.Light.Radius, 4f)), "a front-layer lamp");
+            ModAssert.True(lights.Exists(l => l.Cell == new Vector2I(2, 2)), "a cell lit on two layers counts once");
+        }
+
+        [ModTest("lights/map_ambient_json")]
+        static void MapAmbientJson(ModTestContext ctx)
+        {
+            var room = JsonSerializer.Deserialize<RpgMap>(@"{ ""ID"": ""room"", ""Ambient"": ""#e8dcc8"" }", JsonOptionsProvider.ReadOptions);
+            ModAssert.Equal("#e8dcc8", room.Ambient, "a lit room");
+            var again = JsonSerializer.Deserialize<RpgMap>(JsonSerializer.Serialize(room), JsonOptionsProvider.ReadOptions);
+            ModAssert.Equal("#e8dcc8", again.Ambient, "ambient survives the round trip");
+            ModAssert.Null(JsonSerializer.Deserialize<RpgMap>(@"{ ""ID"": ""field"" }", JsonOptionsProvider.ReadOptions).Ambient, "outdoors by default");
+        }
+    }
+}

tests/RpgRulesTests.cs

@@ -53,6 +53,26 @@ namespace Cthangover.Mods.Rpg.Tests
             ModAssert.False(tileset.IsSolid(-1), "empty cell");
         }
 
+        [ModTest("rules/tileset_light_and_autotile_lookup_round_trip")]
+        static void TilesetLightAndAutotileLookup(ModTestContext ctx)
+        {
+            var tileset = System.Text.Json.JsonSerializer.Deserialize<RpgTileset>(@"{
+                ""Id"": ""lit"", ""Tiles"": [
+                  { ""Index"": 29, ""Tag"": ""lamp_top"", ""Light"": { ""Radius"": 4, ""Color"": ""#ffcf80"" } },
+                  { ""Index"": 40, ""Solid"": true, ""Tag"": ""water"", ""Autotile"": ""village/water_auto"" }
+                ] }", Cthangover.Core.Utils.JsonOptionsProvider.ReadOptions);
+            tileset = System.Text.Json.JsonSerializer.Deserialize<RpgTileset>(System.Text.Json.JsonSerializer.Serialize(tileset), Cthangover.Core.Utils.JsonOptionsProvider.ReadOptions);
+
+            ModAssert.CloseTo(4, tileset.LightOf(29).Radius, what: "the lamp's light survives the round trip");
+            ModAssert.Equal("#ffcf80", tileset.LightOf(29).Color, "with its colour");
+            ModAssert.Null(tileset.LightOf(40), "the water gives no light");
+            ModAssert.Null(tileset.LightOf(-1), "an empty cell gives no light");
+            ModAssert.Equal("village/water_auto", tileset.AutotileOf(40)?.Autotile, "the autotile entry and its block");
+            ModAssert.Null(tileset.AutotileOf(29), "a plain tile is no autotile");
+            ModAssert.Null(tileset.AutotileOf(-1), "nor an empty cell");
+            ModAssert.True(tileset.IsSolid(40), "an autotile is solid like any tile");
+        }
+
         [ModTest("rules/encounter_off_without_table")]
         static void EncounterOffWithoutTable(ModTestContext ctx)
         {

tests/RpgStateTests.cs

@@ -57,7 +57,6 @@ namespace Cthangover.Mods.Rpg.Tests
         {
             var json = @"{""Id"":""m"",""Tileset"":""village"",""Width"":2,""Height"":1,
                 ""Spawn"":{""X"":1,""Y"":0,""Dir"":""left""},
-                ""Events"":[{""Id"":""door"",""X"":0,""Y"":0,""Trigger"":""touch"",""Teleport"":{""Map"":""x"",""X"":3,""Y"":4,""Dir"":""Up""}}],
                 ""Encounters"":{""Steps"":20,""Groups"":[""slime""]}}";
 
             var map = JsonSerializer.Deserialize<RpgMap>(json, Cthangover.Core.Utils.JsonOptionsProvider.ReadOptions);
@@ -65,12 +64,63 @@ namespace Cthangover.Mods.Rpg.Tests
 
             ModAssert.Equal("m", again.ID, "id");
             ModAssert.Equal("Left", again.Spawn.Dir.ToString(), "spawn facing, read in any case");
+            ModAssert.Equal(20, again.Encounters.Steps, "encounter steps");
+            ModAssert.Equal("slime", again.Encounters.Groups[0], "encounter group");
+            ModAssert.Equal(2, again.Zoom, "zoom default");
+        }
+
+        [ModTest("state/event_file_round_trip")]
+        static void EventFileRoundTrip(ModTestContext ctx)
+        {
+            var json = @"{""Events"":[
+                {""Id"":""door"",""X"":0,""Y"":0,""Trigger"":""touch"",""Teleport"":{""Map"":""x"",""X"":3,""Y"":4,""Dir"":""Up""}},
+                {""Id"":""herb"",""X"":2,""Y"":1,""Icon"":""rpg_demo/forest_mushroom"",""Commands"":[""end""],""Condition"":""herb != 1""}]}";
+
+            var file = JsonSerializer.Deserialize<RpgMapEventFile>(json, Cthangover.Core.Utils.JsonOptionsProvider.ReadOptions);
+            file.Events[0].ModId = "some_mod";
+            var text = JsonSerializer.Serialize(file);
+            var again = JsonSerializer.Deserialize<RpgMapEventFile>(text, Cthangover.Core.Utils.JsonOptionsProvider.ReadOptions);
+
+            ModAssert.Equal(2, again.Events.Count, "both events");
             ModAssert.Equal("Touch", again.Events[0].Trigger.ToString(), "trigger");
             ModAssert.Equal("x", again.Events[0].Teleport.Map, "teleport map");
             ModAssert.Equal(4, again.Events[0].Teleport.Y, "teleport y");
             ModAssert.False(again.Events[0].IsSolid, "an invisible event does not block");
-            ModAssert.Equal(20, again.Encounters.Steps, "encounter steps");
-            ModAssert.Equal(2, again.Zoom, "zoom default");
+            ModAssert.Equal("rpg_demo/forest_mushroom", again.Events[1].Icon, "icon");
+            ModAssert.True(again.Events[1].IsSolid, "an icon is drawn, so it blocks unless told otherwise");
+            ModAssert.Equal("herb != 1", again.Events[1].Condition, "condition");
+            ModAssert.Equal("end", again.Events[1].Commands[0], "commands");
+            ModAssert.False(text.Contains("some_mod"), "where an event came from is not written");
+            ModAssert.False(text.Contains("IsSolid"), "the computed solidity is not written");
+        }
+
+        [ModTest("state/event_merge_adds_and_replaces")]
+        static void EventMergeAddsAndReplaces(ModTestContext ctx)
+        {
+            var merge = new RpgMapEventMerge();
+            merge.Add("village", "base_game", "map_events/village/events.json", new[]
+            {
+                new RpgMapEvent { Id = "elder", X = 1, Y = 1 },
+                new RpgMapEvent { Id = "sign", X = 2, Y = 1 },
+                new RpgMapEvent { Id = " " }
+            });
+            var replaced = merge.Add("VILLAGE", "quest_mod", "map_events/village/quest.json", new[]
+            {
+                new RpgMapEvent { Id = "Elder", X = 5, Y = 5 },
+                new RpgMapEvent { Id = "quest_giver", X = 3, Y = 3 }
+            });
+            merge.Add("forest", "quest_mod", "map_events/forest/a.json", null);
+
+            var village = merge.Maps["village"];
+            ModAssert.Equal(3, village.Count, "an event without an id is skipped, a new id is added");
+            ModAssert.Equal(1, replaced.Count, "one replacement reported");
+            ModAssert.Equal("Elder", replaced[0], "the replacing id");
+            ModAssert.Equal(5, village[0].X, "the later mod's event replaces in place (any case)");
+            ModAssert.Equal("quest_mod", village[0].ModId, "the replacement remembers its mod");
+            ModAssert.Equal("sign", village[1].Id, "the others keep their order");
+            ModAssert.Equal("base_game", village[1].ModId, "and their mod");
+            ModAssert.Equal("map_events/village/quest.json", village[2].File, "an added event remembers its file");
+            ModAssert.Equal(0, merge.Maps["forest"].Count, "a file without events adds nothing");
         }
     }
 }