diff --git a/clash_royale/envs/game_engine/arena.py b/clash_royale/envs/game_engine/arena.py
index 004f005..1c43e20 100644
--- a/clash_royale/envs/game_engine/arena.py
+++ b/clash_royale/envs/game_engine/arena.py
@@ -8,6 +8,9 @@
 
 from typing import TYPE_CHECKING
 
+import numpy as np
+import numpy.typing as npt
+
 from clash_royale.envs.game_engine.entities.entity import Entity, EntityCollection
 from clash_royale.envs.game_engine.card import Card
 
@@ -50,3 +53,6 @@ def get_entities(self) -> List[Entity]:
 
     def play_card(self, x: int, y: int, card: Card) -> None:
         pass
+
+    def get_placement_mask(self) -> npt.NDArray[bool]:
+        return np.ones(shape=(32, 18), dtype=bool)
diff --git a/clash_royale/envs/game_engine/struct.py b/clash_royale/envs/game_engine/struct.py
index 4707e13..c59283a 100644
--- a/clash_royale/envs/game_engine/struct.py
+++ b/clash_royale/envs/game_engine/struct.py
@@ -46,6 +46,9 @@ def game_state(self) -> int:
         ex: Game is over, double elixir, overtime, etc.
         """
         return 0
+    
+    def is_game_over(self) -> bool:
+        return False