diff --git a/doc/planning.md b/doc/planning.md
index dda4a31..5c80dde 100644
--- a/doc/planning.md
+++ b/doc/planning.md
@@ -9,6 +9,8 @@
         - Temperature layer (normal and different levels of coldness, transparent solid color)
 - Design a tilemap for the game
 - Player (Dome)
+    - As a layer in the tilemap
+    - Implemented in the PlayerManager
     - Stats (see document)
     - Inventory
         - with one slot
@@ -18,7 +20,7 @@
     - Use tilemap layers to compute route
     - Support obstacles
     - Result must be an array of tile coordinates, length (array length) and the total cost (sum of weights)
-- Decision Tree (Classes, etc.) (Luca, Cool in)
+- Decision Tree (Classes, etc.) (Yan)
     - Reference Food Gatherer for implementation
     - Child of player, serves as controller
     - Script needs access to the scene, player and other objects/data
diff --git a/project/assets/tilemap/tilemaps/sprite.json b/project/assets/tilemap/tilemaps/sprite.json
index 8c162bc..c06eee1 100644
--- a/project/assets/tilemap/tilemaps/sprite.json
+++ b/project/assets/tilemap/tilemaps/sprite.json
@@ -1,48 +1,48 @@
 {
+	"filename": "tilemaps.aseprite",
 	"height": 320,
+	"width": 320,
 	"layers": [
 		{
+			"name": "ground",
 			"cels": [
 				{
 					"image": "tilemaps\\tilemap_ground.png",
 					"frame": 0
 				}
-			],
-			"name": "ground"
+			]
 		},
 		{
+			"name": "objects",
 			"cels": [
 				{
 					"image": "tilemaps\\tilemap_objects.png",
 					"frame": 0
 				}
-			],
-			"name": "objects"
+			]
 		},
 		{
+			"name": "temperature",
 			"cels": [
 				{
 					"image": "tilemaps\\tilemap_temperature.png",
 					"frame": 0
 				}
-			],
-			"name": "temperature"
+			]
 		},
 		{
+			"name": "player",
 			"cels": [
 				{
 					"image": "tilemaps\\tilemap_player.png",
 					"frame": 0
 				}
-			],
-			"name": "player"
+			]
 		}
 	],
-	"width": 320,
 	"frames": [
 		{
 			"duration": 0.1
 		}
-	],
-	"filename": "tilemaps.aseprite"
+	]
 }
\ No newline at end of file
diff --git a/project/main-scenes/island.tscn b/project/main-scenes/island.tscn
index ee4505e..e248ef9 100644
--- a/project/main-scenes/island.tscn
+++ b/project/main-scenes/island.tscn
@@ -1,10 +1,14 @@
-[gd_scene load_steps=6 format=4 uid="uid://b88asko1ugyd2"]
+[gd_scene load_steps=10 format=4 uid="uid://b88asko1ugyd2"]
 
 [ext_resource type="Script" path="res://scripts/global/GameManager.gd" id="1_eeg2d"]
 [ext_resource type="Script" path="res://scripts/tilemap/World.gd" id="1_k0rw8"]
 [ext_resource type="TileSet" uid="uid://bi836ygcmyvhb" path="res://assets/tilemap/tileset.tres" id="1_vlccq"]
 [ext_resource type="Script" path="res://scripts/global/Camera.gd" id="2_1vbjl"]
 [ext_resource type="Script" path="res://scripts/player/PlayerManager.gd" id="4_1xqo1"]
+[ext_resource type="Script" path="res://scripts/player/tree/BehaviorTree.gd" id="6_efs30"]
+[ext_resource type="Script" path="res://scripts/player/tree/impl/base/TaskSelector.gd" id="7_1jajd"]
+[ext_resource type="Script" path="res://scripts/player/tree/impl/context/Task5050Success.gd" id="8_xrswf"]
+[ext_resource type="Script" path="res://scripts/player/tree/impl/context/Task5050Running.gd" id="9_r13cd"]
 
 [node name="Island-scene" type="Node2D"]
 script = ExtResource("1_eeg2d")
@@ -33,3 +37,18 @@ tile_set = ExtResource("1_vlccq")
 
 [node name="PlayerManager" type="Node" parent="."]
 script = ExtResource("4_1xqo1")
+
+[node name="BehaviorTree" type="Node" parent="PlayerManager"]
+script = ExtResource("6_efs30")
+
+[node name="sl_Root" type="Node" parent="PlayerManager/BehaviorTree"]
+script = ExtResource("7_1jajd")
+
+[node name="Node" type="Node" parent="PlayerManager/BehaviorTree/sl_Root"]
+script = ExtResource("7_1jajd")
+
+[node name="5050Success" type="Node" parent="PlayerManager/BehaviorTree/sl_Root/Node"]
+script = ExtResource("8_xrswf")
+
+[node name="5050Running" type="Node" parent="PlayerManager/BehaviorTree/sl_Root/Node"]
+script = ExtResource("9_r13cd")
diff --git a/project/project.godot b/project/project.godot
index 154e68d..cd658d0 100644
--- a/project/project.godot
+++ b/project/project.godot
@@ -76,6 +76,11 @@ key_9={
 "events": [Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"pressed":false,"keycode":0,"physical_keycode":57,"key_label":0,"unicode":57,"location":0,"echo":false,"script":null)
 ]
 }
+force_game_tick={
+"deadzone": 0.5,
+"events": [Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"pressed":false,"keycode":0,"physical_keycode":70,"key_label":0,"unicode":102,"location":0,"echo":false,"script":null)
+]
+}
 
 [rendering]
 
diff --git a/project/scripts/global/GameManager.gd b/project/scripts/global/GameManager.gd
index 735f63e..cf54b03 100644
--- a/project/scripts/global/GameManager.gd
+++ b/project/scripts/global/GameManager.gd
@@ -6,8 +6,7 @@ extends Node
 @onready var camera: Camera2D = $Camera2D
 
 func _ready() -> void:
-    player.world = world
-    player.camera = camera
+    player.game_manager = self
 
 func _process(delta: float) -> void:
     if Input.is_action_just_pressed("key_1"):
@@ -16,3 +15,5 @@ func _process(delta: float) -> void:
         camera.go_to_zooming(Vector2(789.883972167969, 450.102813720703), 0.56015348434448)
     if Input.is_action_just_pressed("key_9"):
         camera.print_config()
+    if Input.is_action_just_pressed("force_game_tick"):
+        player.game_tick()
diff --git a/project/scripts/player/PlayerManager.gd b/project/scripts/player/PlayerManager.gd
index 495544e..4f1e95d 100644
--- a/project/scripts/player/PlayerManager.gd
+++ b/project/scripts/player/PlayerManager.gd
@@ -1,19 +1,32 @@
 class_name PlayerManager
 extends Node
 
-var board_position: Vector2 = Vector2(0, 0)
-var world: World = null
-var camera: Camera2D = null
-#
 var tilemap_types: TileMapTileTypes = TileMapTileTypes.new()
+#
+var game_manager: GameManager = null
+var board_position: Vector2   = Vector2(0, 0)
+
+@onready var behavior_tree: BehaviorTree = $BehaviorTree
+
 
 func _ready() -> void:
-    call_deferred("update_board")
+    call_deferred("defer_ready")
+
+
+func defer_ready() -> void:
+    behavior_tree.game_manager = game_manager
+    update_board()
+
 
 func _process(delta: float) -> void:
     if Input.is_action_just_pressed("key_3"):
-        camera.go_to_zooming(world.tilemap_player.cell_to_local(board_position), 2)
+        game_manager.camera.go_to_zooming(game_manager.world.tilemap_player.cell_to_local(board_position), 2)
+
 
 func update_board() -> void:
-    world.tilemap_player.clear_cells()
-    world.tilemap_player.set_cell(board_position, tilemap_types.PLAYER)
+    game_manager.world.tilemap_player.clear_cells()
+    game_manager.world.tilemap_player.set_cell(board_position, tilemap_types.PLAYER)
+
+
+func game_tick() -> void:
+    behavior_tree.game_tick()
diff --git a/project/scripts/player/tree/BehaviorTree.gd b/project/scripts/player/tree/BehaviorTree.gd
new file mode 100644
index 0000000..536c007
--- /dev/null
+++ b/project/scripts/player/tree/BehaviorTree.gd
@@ -0,0 +1,31 @@
+class_name BehaviorTree
+extends Node
+
+var game_manager: GameManager = null
+#
+var blackboard: Dictionary = {}
+var behavior_tree: Task    = null
+
+
+func _ready() -> void:
+    if get_child_count() == 0 or get_child_count() > 1:
+        push_error("This controller needs exactly one Task child, got " + str(get_child_count()))
+
+    var child: Node = get_child(0)
+    if not (child is Task):
+        push_error("Child is not a task: " + child.name)
+
+    behavior_tree = child as Task
+
+
+func populate_blackboard():
+    blackboard["world"] = game_manager.world
+    blackboard["player"] = game_manager.player
+    blackboard["camera"] = game_manager.camera
+
+
+func game_tick() -> void:
+    print("game_tick:")
+    populate_blackboard()
+    behavior_tree.internal_run(blackboard)
+    print(" ==> [active state=", blackboard["current_task"], "] [status=", behavior_tree.status, "]")
diff --git a/project/scripts/player/tree/Task.gd b/project/scripts/player/tree/Task.gd
new file mode 100644
index 0000000..ee43085
--- /dev/null
+++ b/project/scripts/player/tree/Task.gd
@@ -0,0 +1,56 @@
+class_name Task
+extends Node
+
+enum {FAILURE = -1, SUCCESS = 1, RUNNING = 0}
+var status: int = FAILURE
+
+
+func _ready() -> void:
+    for c in get_children():
+        if not c is Task:
+            push_error("Child is not a task: " + c.name + " in " + name)
+            return
+
+
+func internal_run(p_blackboard: Dictionary) -> void:
+    p_blackboard["current_task"] = self
+
+    if status == RUNNING:
+        var running_child: Task = find_running_child()
+        if running_child != null:
+            running_child.internal_run(p_blackboard)
+            status = running_child.status
+            return
+        else:
+            run(p_blackboard)
+    else:
+        run(p_blackboard)
+    print(" - ", name, " ", status)
+
+
+func find_running_child() -> Task:
+    for c in get_children():
+        if c.status == RUNNING:
+            return c
+    return null
+
+
+func run_child(p_blackboard: Dictionary, p_child: Task) -> void:
+    p_child.internal_run(p_blackboard)
+    if p_child.status != RUNNING:
+        status = RUNNING
+
+
+func run(p_blackboard: Dictionary) -> void:
+    pass
+
+
+func cancel(p_blackboard: Dictionary):
+    pass
+
+
+func get_first_child() -> Task:
+    if get_child_count() == 0:
+        push_error("Task does not have any children: " + name)
+        return null
+    return get_children()[0] as Task
diff --git a/project/scripts/player/tree/impl/base/TaskSelector.gd b/project/scripts/player/tree/impl/base/TaskSelector.gd
new file mode 100644
index 0000000..07b705e
--- /dev/null
+++ b/project/scripts/player/tree/impl/base/TaskSelector.gd
@@ -0,0 +1,11 @@
+class_name TaskSelector
+extends Task
+
+func run(blackboard: Dictionary) -> void:
+    for c in self.get_children():
+        run_child(blackboard, c)
+        if c.status != FAILURE:
+            status = c.status
+            return
+    status = FAILURE
+			
diff --git a/project/scripts/player/tree/impl/base/TaskSequence.gd b/project/scripts/player/tree/impl/base/TaskSequence.gd
new file mode 100644
index 0000000..f7a7b80
--- /dev/null
+++ b/project/scripts/player/tree/impl/base/TaskSequence.gd
@@ -0,0 +1,10 @@
+class_name TaskSequence
+extends Task
+
+func run(blackboard: Dictionary) -> void:
+    for c in self.get_children():
+        run_child(blackboard, c)
+        if c.status != SUCCESS:
+            status = c.status
+            return
+    status = SUCCESS
diff --git a/project/scripts/player/tree/impl/context/Task5050Running.gd b/project/scripts/player/tree/impl/context/Task5050Running.gd
new file mode 100644
index 0000000..17ca558
--- /dev/null
+++ b/project/scripts/player/tree/impl/context/Task5050Running.gd
@@ -0,0 +1,9 @@
+class_name Task5050Running
+extends Task
+
+func run(blackboard: Dictionary) -> void:
+    var random: int = randi() % 2
+    if random == 0:
+        status = RUNNING
+    else:
+        status = SUCCESS
diff --git a/project/scripts/player/tree/impl/context/Task5050Success.gd b/project/scripts/player/tree/impl/context/Task5050Success.gd
new file mode 100644
index 0000000..94ea92b
--- /dev/null
+++ b/project/scripts/player/tree/impl/context/Task5050Success.gd
@@ -0,0 +1,9 @@
+class_name Task5050Success
+extends Task
+
+func run(blackboard: Dictionary) -> void:
+    var random: int = randi() % 2
+    if random == 0:
+        status = SUCCESS
+    else:
+        status = FAILURE