diff --git a/g.py b/g.py
index e30e095..52bf2ab 100644
--- a/g.py
+++ b/g.py
@@ -6,7 +6,7 @@ import tcod.console
 import tcod.context
 import tcod.ecs
 
-from game.screens import Screen
+import game.state
 from game.components import Position
 
 context: tcod.context.Context
@@ -15,9 +15,12 @@ context: tcod.context.Context
 world: tcod.ecs.Registry
 """The active ECS registry and current session."""
 
+world_map: tcod.map.Map
+"""Wall Map of current World"""
+
 world_center: tuple[int,int] = Position(50, 50)
 
-screens: list[Screen] = []
+states: list[game.state.State] = []
 """A stack of states with the last item being the active state."""
 
 console: tcod.console.Console
diff --git a/game/screens/menus.py b/game/menus.py
similarity index 85%
rename from game/screens/menus.py
rename to game/menus.py
index 7927cc5..7c1bb37 100644
--- a/game/screens/menus.py
+++ b/game/menus.py
@@ -10,8 +10,9 @@ import tcod.console
 import tcod.event
 from tcod.event import KeySym
 
+import game.state_tools
 from game.constants import DIRECTION_KEYS
-from game.screens import Pop, Screen, ScreenResult, draw_previous_screens
+from game.state import Pop, State, StateResult
 
 
 class MenuItem(Protocol):
@@ -19,7 +20,7 @@ class MenuItem(Protocol):
 
     __slots__ = ()
 
-    def on_event(self, event: tcod.event.Event) -> ScreenResult:
+    def on_event(self, event: tcod.event.Event) -> StateResult:
         """Handle events passed to the menu item."""
 
     def on_draw(self, console: tcod.console.Console, x: int, y: int, highlight: bool) -> None:
@@ -31,9 +32,9 @@ class SelectItem(MenuItem):
     """Clickable menu item."""
 
     label: str
-    callback: Callable[[], ScreenResult]
+    callback: Callable[[], StateResult]
 
-    def on_event(self, event: tcod.event.Event) -> ScreenResult:
+    def on_event(self, event: tcod.event.Event) -> StateResult:
         """Handle events selecting this item."""
         match event:
             case tcod.event.KeyDown(sym=sym) if sym in {KeySym.RETURN, KeySym.RETURN2, KeySym.KP_ENTER}:
@@ -49,7 +50,7 @@ class SelectItem(MenuItem):
 
 
 @attrs.define()
-class ListMenu(Screen):
+class ListMenu(State):
     """Simple list menu state."""
 
     items: tuple[MenuItem, ...]
@@ -57,7 +58,7 @@ class ListMenu(Screen):
     x: int = 0
     y: int = 0
 
-    def on_event(self, event: tcod.event.Event) -> ScreenResult:
+    def on_event(self, event: tcod.event.Event) -> StateResult:
         """Handle events for menus."""
         match event:
             case tcod.event.Quit():
@@ -83,18 +84,18 @@ class ListMenu(Screen):
             case _:
                 return self.activate_selected(event)
 
-    def activate_selected(self, event: tcod.event.Event) -> ScreenResult:
+    def activate_selected(self, event: tcod.event.Event) -> StateResult:
         """Call the selected menu items callback."""
         if self.selected is not None:
             return self.items[self.selected].on_event(event)
         return None
 
-    def on_cancel(self) -> ScreenResult:
+    def on_cancel(self) -> StateResult:
         """Handle escape or right click being pressed on menus."""
         return Pop()
 
     def on_draw(self, console: tcod.console.Console) -> None:
         """Render the menu."""
-        draw_previous_screens(self, console)
+        game.state_tools.draw_previous_state(self, console)
         for i, item in enumerate(self.items):
             item.on_draw(console, x=self.x, y=self.y + i, highlight=i == self.selected)
diff --git a/game/screens/__init__.py b/game/screens/__init__.py
deleted file mode 100644
index ee16cc0..0000000
--- a/game/screens/__init__.py
+++ /dev/null
@@ -1,99 +0,0 @@
-"""Package for game state stuff."""
-
-from __future__ import annotations
-
-from typing import Protocol, TypeAlias
-
-import attrs
-import tcod.console
-import tcod.event
-
-import g
-
-
-class Screen(Protocol):
-    """An abstract game screen."""
-
-    __slots__ = ()
-
-    def on_event(self, event: tcod.event.Event) -> ScreenResult:
-        """Called on events."""
-
-    def on_draw(self, console: tcod.console.Console) -> None:
-        """Called when the screen is being drawn."""
-
-
-@attrs.define()
-class Push:
-    """Push a new screen on top of the stack."""
-
-    screen: Screen
-
-
-@attrs.define()
-class Pop:
-    """Remove the current screen from the stack."""
-
-
-@attrs.define()
-class Reset:
-    """Replace the entire stack with a new screen."""
-
-    screen: Screen
-
-
-ScreenResult: TypeAlias = "Push | Pop | Reset | None"
-"""Union of screen results."""
-
-
-def main_draw() -> None:
-    """Render and present the active screen."""
-    if not g.screens:
-        return
-    g.console.clear()
-    g.screens[-1].on_draw(g.console)
-    g.context.present(g.console)
-
-
-def apply_state_result(result: ScreenResult) -> None:
-    """Apply a StateResult to `g.states`."""
-    match result:
-        case Push(screen=screen):
-            g.screens.append(screen)
-        case Pop():
-            g.screens.pop()
-        case Reset(screen=screen):
-            while g.screens:
-                apply_state_result(Pop())
-            apply_state_result(Push(screen))
-        case None:
-            pass
-        case _:
-            raise TypeError(result)
-
-
-def main_loop() -> None:
-    """Run the active state forever."""
-    while g.screens:
-        main_draw()
-        for event in tcod.event.wait():
-            tile_event = g.context.convert_event(event)
-            if g.screens:
-                apply_state_result(g.screens[-1].on_event(tile_event))
-
-
-def get_previous_screen(screen: Screen) -> Screen | None:
-    """Return the state before `state` in the stack if it exists."""
-    current_index = next(index for index, value in enumerate(g.screens) if value is screen)
-    return g.screens[current_index - 1] if current_index > 0 else None
-
-
-def draw_previous_screens(screen: Screen, console: tcod.console.Console, dim: bool = True) -> None:
-    """Draw previous states, optionally dimming all but the active state."""
-    prev_screen = get_previous_screen(screen)
-    if prev_screen is None:
-        return
-    prev_screen.on_draw(console)
-    if dim and screen is g.screens[-1]:
-        console.rgb["fg"] //= 4
-        console.rgb["bg"] //= 4
diff --git a/game/screens/menu_screens.py b/game/screens/menu_screens.py
deleted file mode 100644
index bfa4346..0000000
--- a/game/screens/menu_screens.py
+++ /dev/null
@@ -1,45 +0,0 @@
-"""The main menu state"""
-
-from __future__ import annotations
-
-import g
-import game.screens.menus
-import game.world_tools
-from game.screens import Reset, ScreenResult
-from game.screens.game_screens import MainScreen
-
-class MainMenu(game.screens.menus.ListMenu):
-    """Main/escape menu."""
-    __slots__ = ()
-
-    def __init__(self) -> None:
-        """Initialize the main menu."""
-        items = [
-            game.screens.menus.SelectItem("New game", self.new_game),
-            game.screens.menus.SelectItem("Quit", self.quit),
-        ]
-        if hasattr(g, "world"):
-            items.insert(0, game.screens.menus.SelectItem("Continue", self.continue_))
-
-        super().__init__(
-            items=tuple(items),
-            selected=0,
-            x=5,
-            y=5,
-        )
-
-    @staticmethod
-    def continue_() -> ScreenResult:
-        """Return to the game."""
-        return Reset(MainScreen())
-
-    @staticmethod
-    def new_game() -> ScreenResult:
-        """Begin a new game."""
-        g.world = game.world_tools.new_world()
-        return Reset(MainScreen())
-
-    @staticmethod
-    def quit() -> ScreenResult:
-        """Close the program."""
-        raise SystemExit()
diff --git a/game/state.py b/game/state.py
new file mode 100644
index 0000000..4b935c4
--- /dev/null
+++ b/game/state.py
@@ -0,0 +1,44 @@
+"""Base classes for states."""
+
+from __future__ import annotations
+
+from typing import Protocol, TypeAlias
+
+import attrs
+import tcod.console
+import tcod.event
+
+
+class State(Protocol):
+    """An abstract game state."""
+
+    __slots__ = ()
+
+    def on_event(self, event: tcod.event.Event) -> StateResult:
+        """Called on events."""
+
+    def on_draw(self, console: tcod.console.Console) -> None:
+        """Called when the state is being drawn."""
+
+
+@attrs.define()
+class Push:
+    """Push a new state on top of the stack."""
+
+    state: State
+
+
+@attrs.define()
+class Pop:
+    """Remove the current state from the stack."""
+
+
+@attrs.define()
+class Reset:
+    """Replace the entire stack with a new state."""
+
+    state: State
+
+
+StateResult: TypeAlias = "Push | Pop | Reset | None"
+"""Union of state results."""
diff --git a/game/state_tools.py b/game/state_tools.py
new file mode 100644
index 0000000..77d2e22
--- /dev/null
+++ b/game/state_tools.py
@@ -0,0 +1,61 @@
+"""State handling functions."""
+
+from __future__ import annotations
+
+import tcod.console
+
+import g
+from game.state import Pop, Push, Reset, State, StateResult
+
+
+def main_draw() -> None:
+    """Render and present the active state."""
+    if not g.states:
+        return
+    g.console.clear()
+    g.states[-1].on_draw(g.console)
+    g.context.present(g.console)
+
+
+def apply_state_result(result: StateResult) -> None:
+    """Apply a StateResult to `g.states`."""
+    match result:
+        case Push(state=state):
+            g.states.append(state)
+        case Pop():
+            g.states.pop()
+        case Reset(state=state):
+            while g.states:
+                apply_state_result(Pop())
+            apply_state_result(Push(state))
+        case None:
+            pass
+        case _:
+            raise TypeError(result)
+
+
+def main_loop() -> None:
+    """Run the active state forever."""
+    while g.states:
+        main_draw()
+        for event in tcod.event.wait():
+            tile_event = g.context.convert_event(event)
+            if g.states:
+                apply_state_result(g.states[-1].on_event(tile_event))
+
+
+def get_previous_state(state: State) -> State | None:
+    """Return the state before `state` in the stack if it exists."""
+    current_index = next(index for index, value in enumerate(g.states) if value is state)
+    return g.states[current_index - 1] if current_index > 0 else None
+
+
+def draw_previous_state(state: State, console: tcod.console.Console, dim: bool = True) -> None:
+    """Draw previous states, optionally dimming all but the active state."""
+    prev_state = get_previous_state(state)
+    if prev_state is None:
+        return
+    prev_state.on_draw(console)
+    if dim and state is g.states[-1]:
+        console.rgb["fg"] //= 4
+        console.rgb["bg"] //= 4
diff --git a/game/screens/game_screens.py b/game/states.py
similarity index 69%
rename from game/screens/game_screens.py
rename to game/states.py
index e9bc948..181a13c 100644
--- a/game/screens/game_screens.py
+++ b/game/states.py
@@ -1,28 +1,28 @@
-"""All states the are used in-game"""
+"""A collection of game states."""
 
 from __future__ import annotations
+from functools import reduce
 
 import attrs
 import tcod.console
 import tcod.constants
 import tcod.event
 from tcod.event import KeySym
-from tcod.map import Map
 
 import g
+import game.menus
+import game.world_tools
 from game.components import Gold, Graphic, Position
 from game.constants import DIRECTION_KEYS, ACTION_KEYS
-from game.screens import Push, Screen, ScreenResult
+from game.state import Push, Reset, State, StateResult
 from game.tags import IsItem, IsPlayer, IsDoor, IsActor
 from game.constants import WALL_CHAR
-from game.screens import menu_screens
-
 
 @attrs.define()
-class MainScreen(Screen):
+class InGame(State):
     """Primary in-game state."""
 
-    def on_event(self, event: tcod.event.Event) -> ScreenResult:
+    def on_event(self, event: tcod.event.Event) -> StateResult:
         """Handle events for the in-game state."""
         (player,) = g.world.Q.all_of(tags=[IsPlayer])
         match event:
@@ -34,7 +34,7 @@ class MainScreen(Screen):
                 raise SystemExit()
             case tcod.event.KeyDown(sym=sym) if sym in DIRECTION_KEYS:
                 new_pos = player.components[Position] + DIRECTION_KEYS[sym]
-                if not g.world[None].components[Map].walkable[g.world_center.y+new_pos.y][g.world_center.x+new_pos.x]:
+                if not g.world_map.walkable[g.world_center.y+new_pos.y][g.world_center.x+new_pos.x]:
                     return None
                 player.components[Position] = new_pos
                 # Auto pickup gold
@@ -45,7 +45,7 @@ class MainScreen(Screen):
                     gold.clear()
                 return None
             case tcod.event.KeyDown(sym=KeySym.ESCAPE):
-                return Push(menu_screens.MainMenu())
+                return Push(MainMenu())
             case _:
                 return None
 
@@ -62,7 +62,7 @@ class MainScreen(Screen):
                 and -h <= screen_pos.y < h):
                 graphic = e_graph
                 console.rgb[["ch", "fg"]][screen_pos.y + h, screen_pos.x + w] = graphic.ch, graphic.fg
-        for (y, row) in enumerate(g.world[None].components[Map].walkable):
+        for (y, row) in enumerate(g.world_map.walkable):
             for (x, val) in enumerate(row):
                 if not val:
                     draw(Position(x,y)-g.world_center, Graphic(WALL_CHAR))
@@ -74,3 +74,41 @@ class MainScreen(Screen):
             draw(player.components[Position], player.components[Graphic])
         if text := g.world[None].components.get(("Text", str)):
             console.print(x=0, y=console.height - 1, string=text, fg=(255, 255, 255), bg=(0, 0, 0))
+
+
+class MainMenu(game.menus.ListMenu):
+    """Main/escape menu."""
+
+    __slots__ = ()
+
+    def __init__(self) -> None:
+        """Initialize the main menu."""
+        items = [
+            game.menus.SelectItem("New game", self.new_game),
+            game.menus.SelectItem("Quit", self.quit),
+        ]
+        if hasattr(g, "world"):
+            items.insert(0, game.menus.SelectItem("Continue", self.continue_))
+
+        super().__init__(
+            items=tuple(items),
+            selected=0,
+            x=5,
+            y=5,
+        )
+
+    @staticmethod
+    def continue_() -> StateResult:
+        """Return to the game."""
+        return Reset(InGame())
+
+    @staticmethod
+    def new_game() -> StateResult:
+        """Begin a new game."""
+        g.world = game.world_tools.new_world()
+        return Reset(InGame())
+
+    @staticmethod
+    def quit() -> StateResult:
+        """Close the program."""
+        raise SystemExit()
diff --git a/game/world_tools.py b/game/world_tools.py
index fc7022e..65b93c7 100644
--- a/game/world_tools.py
+++ b/game/world_tools.py
@@ -14,18 +14,13 @@ from game.tags import IsActor, IsItem, IsPlayer, IsDoor
 
 def add_wall(pos, remove=False):
     r_pos = g.world_center + pos
-    map = g.world[None].components[Map]
-    map.walkable[r_pos.y][r_pos.x] = remove
-    map.transparent[r_pos.y][r_pos.x] = remove
+    g.world_map.walkable[r_pos.y][r_pos.x] = remove
 
 def add_door(pos):
-    g.world.new_entity(
-        components={
-            Position: pos,
-            Graphic: Graphic(ord('\\'))
-        },
-        tags=[IsDoor]
-    )
+    door = g.world[object()]
+    door.tags.add(IsDoor)
+    door.components[Position] = pos
+    door.components[Graphic] = Graphic(ord("\\"))
     add_wall(pos)
 
 
@@ -33,36 +28,22 @@ def new_world() -> Registry:
     """Return a freshly generated world."""
     world = Registry()
     g.world = world
-
-    map = world[None].components[Map] = Map(100, 100)
-    map.walkable[:] = True
-    map.transparent[:] = True
-
+    g.world_map = Map(100, 100)
+    g.world_map.walkable[:] = True
     rng = world[None].components[Random] = Random()
 
-    world.new_entity(
-        components={
-            Position: Position(5,5),
-            Graphic: Graphic(ord('@')),
-            Gold: 0
-        },
-        tags=[IsActor, IsPlayer]
-    )
-    # player = world[object()] # <- das hier ist das gleiche wie das world.new_entity darüber
-    # player.components[Position] = Position(5, 5)
-    # player.components[Graphic] = Graphic(ord("@"))
-    # player.components[Gold] = 0
-    # player.tags |= {IsPlayer, IsActor}
+    player = world[object()]
+    player.components[Position] = Position(5, 5)
+    player.components[Graphic] = Graphic(ord("@"))
+    player.components[Gold] = 0
+    player.tags |= {IsPlayer, IsActor}
 
     for _ in range(10):
-        world.new_entity(
-            components={
-                Position: Position(rng.randint(0, 20), rng.randint(0, 20)),
-                Graphic: Graphic(ord("$"), fg=(255, 255, 0)),
-                Gold: rng.randint(1, 10)
-            },
-            tags=[IsItem]
-        )
+        gold = world[object()]
+        gold.components[Position] = Position(rng.randint(0, 20), rng.randint(0, 20))
+        gold.components[Graphic] = Graphic(ord("$"), fg=(255, 255, 0))
+        gold.components[Gold] = rng.randint(1, 10)
+        gold.tags |= {IsItem}
 
     for i in range(20):
         if i == 5 or i == 9:
@@ -76,4 +57,5 @@ def new_world() -> Registry:
 def unlock_door(door: Entity):
     door.components[Graphic] = Graphic(ord("_"))
     door.tags.clear()
-    add_wall(door.components[Position], remove=True)
+    pos = door.components[Position]
+    add_wall(pos, remove=True)
diff --git a/main.py b/main.py
index 226a327..176aefd 100755
--- a/main.py
+++ b/main.py
@@ -8,9 +8,8 @@ import tcod.context
 import tcod.tileset
 
 import g
-
-import game.screens
-from game.screens.menu_screens import MainMenu
+import game.state_tools
+import game.states
 
 def main() -> None:
     """Entry point function."""
@@ -19,10 +18,10 @@ def main() -> None:
     )
     tcod.tileset.procedural_block_elements(tileset=tileset)
 
-    g.screens = [MainMenu()]
+    g.states = [game.states.MainMenu()]
     g.console = tcod.console.Console(80, 50)
     with tcod.context.new(console=g.console, tileset=tileset) as g.context:
-        game.screens.main_loop()
+        game.state_tools.main_loop()
 
 
 if __name__ == "__main__":