diff --git a/.github/workflows/pr.yml b/.github/workflows/pr.yml
index 1f14faa..4d3a579 100644
--- a/.github/workflows/pr.yml
+++ b/.github/workflows/pr.yml
@@ -27,6 +27,9 @@ jobs:
     - name: Check formatting
       run: pipenv run black --target-version=py310 .
 
+    - name: Check types
+      run: pipenv run mypy rps rps-sim.py
+
     - name: Run tests
       run: |
         pipenv run pytest
diff --git a/Pipfile b/Pipfile
index 118ea5e..82d3192 100644
--- a/Pipfile
+++ b/Pipfile
@@ -19,6 +19,7 @@ black = "*"
 pytest = "*"
 pytest-mock = "*"
 mypy-extensions = "*"
+mypy = "*"
 
 [requires]
 python_version = "3.10"
diff --git a/Pipfile.lock b/Pipfile.lock
index 987bd57..a1e9c47 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "6b1367d5919f0d578a501fd1a53545155842a4145ab195240d90fced34562864"
+            "sha256": "1dd7436d3bb287d8b187a5c5c9765431941777c6ccc27ed25fc9e24f85acec92"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -150,6 +150,34 @@
             "index": "pypi",
             "version": "==2.0.0"
         },
+        "mypy": {
+            "hashes": [
+                "sha256:1fe816e26e676c1311b9e04fd576543b873576d39439f7c24c8e5c7728391ecf",
+                "sha256:2c9d570f53908cbea326ad8f96028a673b814d9dca7515bf71d95fa662c3eb6f",
+                "sha256:35b13335c6c46a386577a51f3d38b2b5d14aa619e9633bb756bd77205e4bd09f",
+                "sha256:372fd97293ed0076d52695849f59acbbb8461c4ab447858cdaeaf734a396d823",
+                "sha256:42170e68adb1603ccdc55a30068f72bcfcde2ce650188e4c1b2a93018b826735",
+                "sha256:69b32d0dedd211b80f1b7435644e1ef83033a2af2ac65adcdc87c38db68a86be",
+                "sha256:725b57a19b7408ef66a0fd9db59b5d3e528922250fb56e50bded27fea9ff28f0",
+                "sha256:769ddb6bfe55c2bd9c7d6d7020885a5ea14289619db7ee650e06b1ef0852c6f4",
+                "sha256:79c520aa24f21852206b5ff2cf746dc13020113aa73fa55af504635a96e62718",
+                "sha256:84cf9f7d8a8a22bb6a36444480f4cbf089c917a4179fbf7eea003ea931944a7f",
+                "sha256:9166186c498170e1ff478a7f540846b2169243feb95bc228d39a67a1a450cdc6",
+                "sha256:a2500ad063413bc873ae102cf655bf49889e0763b260a3a7cf544a0cbbf7e70a",
+                "sha256:a551ed0fc02455fe2c1fb0145160df8336b90ab80224739627b15ebe2b45e9dc",
+                "sha256:ad3109bec37cc33654de8db30fe8ff3a1bb57ea65144167d68185e6dced9868d",
+                "sha256:b4ea3a0241cb005b0ccdbd318fb99619b21ae51bcf1660b95fc22e0e7d3ba4a1",
+                "sha256:c36011320e452eb30bec38b9fd3ba20569dc9545d7d4540d967f3ea1fab9c374",
+                "sha256:c8a7444d6fcac7e2585b10abb91ad900a576da7af8f5cffffbff6065d9115813",
+                "sha256:cbf18f8db7e5f060d61c91e334d3b96d6bb624ddc9ee8a1cde407b737acbca2c",
+                "sha256:d145b81a8214687cfc1f85c03663a5bbe736777410e5580e54d526e7e904f564",
+                "sha256:eec5c927aa4b3e8b4781840f1550079969926d0a22ce38075f6cfcf4b13e3eb4",
+                "sha256:f3460f34b3839b9bc84ee3ed65076eb827cd99ed13ed08d723f9083cada4a212",
+                "sha256:f3940cf5845b2512b3ab95463198b0cdf87975dfd17fdcc6ce9709a9abe09e69"
+            ],
+            "index": "pypi",
+            "version": "==1.5.0"
+        },
         "mypy-extensions": {
             "hashes": [
                 "sha256:4392f6c0eb8a5668a69e23d168ffa70f0be9ccfd32b5cc2d26a34ae5b844552d",
@@ -213,6 +241,14 @@
             ],
             "index": "pypi",
             "version": "==2.0.1"
+        },
+        "typing-extensions": {
+            "hashes": [
+                "sha256:440d5dd3af93b060174bf433bccd69b0babc3b15b1a8dca43789fd7f61514b36",
+                "sha256:b75ddc264f0ba5615db7ba217daeb99701ad295353c45f9e95963337ceeeffb2"
+            ],
+            "index": "pypi",
+            "version": "==4.7.1"
         }
     }
 }
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..f8ab000
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,2 @@
+[tool.mypy]
+strict = true
\ No newline at end of file
diff --git a/rps/game.py b/rps/game.py
index 09145c5..7899698 100644
--- a/rps/game.py
+++ b/rps/game.py
@@ -1,11 +1,14 @@
-def play_game(firstPlayer, secondPlayer):
+from .player import Player
+from .play import PlayResult
+
+def play_game(firstPlayer: Player, secondPlayer: Player) -> PlayResult:
     firstPlay = firstPlayer.play()
     secondPlay = secondPlayer.play()
     return firstPlay.match(secondPlay)
 
 
-def play_games(firstPlayer, secondPlayer, times):
+def play_games(firstPlayer: Player, secondPlayer: Player, times: int) -> list[PlayResult]:
     results = []
-    for game in range(times):
+    for _ in range(times):
         results.append(play_game(firstPlayer, secondPlayer))
     return results
diff --git a/rps/play.py b/rps/play.py
index 9595062..196beda 100644
--- a/rps/play.py
+++ b/rps/play.py
@@ -1,3 +1,4 @@
+from __future__ import annotations
 from enum import IntEnum
 
 
@@ -7,7 +8,7 @@ class PlayResult(IntEnum):
     WIN = 1
 
 
-def human_readable(result):
+def human_readable(result: PlayResult) -> str:
     if result == PlayResult.WIN:
         return "wins"
     elif result == PlayResult.LOSS:
@@ -21,7 +22,7 @@ class Play(IntEnum):
     PAPER = 2
     SCISSORS = 3
 
-    def match(self, other):
+    def match(self, other: Play) -> PlayResult:
         if self.value == other.value or type(other) is not Play:
             return PlayResult.DRAW
         if self.value == self.ROCK:
@@ -30,11 +31,12 @@ def match(self, other):
             return PlayResult.WIN if other.value == self.PAPER else PlayResult.LOSS
         elif self.value == self.PAPER:
             return PlayResult.WIN if other.value == self.ROCK else PlayResult.LOSS
+        return PlayResult.DRAW
 
     @staticmethod
-    def min():
+    def min() -> int:
         return min([Play.ROCK, Play.PAPER, Play.SCISSORS])
 
     @staticmethod
-    def max():
+    def max() -> int:
         return max([Play.ROCK, Play.PAPER, Play.SCISSORS])
diff --git a/rps/player.py b/rps/player.py
index ee73149..990517a 100644
--- a/rps/player.py
+++ b/rps/player.py
@@ -1,16 +1,18 @@
 import abc
+
+from .play import Play
 from .strategy import PlaySelectionStrategy
 
 
 class Player(object):
     @abc.abstractmethod
-    def play(self):
+    def play(self) -> Play:
         """Required method"""
 
 
 class BotPlayer(Player):
-    def __init__(self, play_strategy):
+    def __init__(self, play_strategy: PlaySelectionStrategy):
         self.__strategy = play_strategy
 
-    def play(self):
+    def play(self)  -> Play:
         return self.__strategy.play()
diff --git a/rps/strategy.py b/rps/strategy.py
index 38dddf2..8e4996b 100644
--- a/rps/strategy.py
+++ b/rps/strategy.py
@@ -7,10 +7,10 @@ class PlaySelectionStrategy(object):
     __metaclass__ = abc.ABCMeta
 
     @abc.abstractmethod
-    def play(self):
+    def play(self) -> Play:
         """Required method"""
 
 
 class RandomPlayStrategy(PlaySelectionStrategy):
-    def play(self):
+    def play(self) -> Play:
         return Play(randrange(Play.min(), Play.max() + 1))