diff --git a/game/main.py b/game/main.py
index 4e76466..85a46c0 100644
--- a/game/main.py
+++ b/game/main.py
@@ -5,13 +5,31 @@
 app = typer.Typer()
 
 
-@app.command()
-def main(map_grid: str = None):
+@app.callback(invoke_without_command=True)
+def main(
+    ctx: typer.Context,
+    map_grid: str = typer.Option(
+        None,
+        "--map-grid",
+        "-m",
+        help="Load a map from a string representation",
+    ),
+):
+    if ctx.invoked_subcommand is not None:
+        return
+
     game_map = Map()
     if map_grid is not None:
         game_map.load_from_str(map_grid)
     game_map.run()
 
 
+@app.command()
+def from_file(file_path: str):
+    game_map = Map()
+    game_map.load_from_file(file_path)
+    game_map.run()
+
+
 if __name__ == "__main__":
     app()
diff --git a/game/tests/cli.py b/game/tests/cli.py
new file mode 100644
index 0000000..f1ddeca
--- /dev/null
+++ b/game/tests/cli.py
@@ -0,0 +1,37 @@
+from game.utils.map import Map
+
+
+def test_from_arg():
+    game_map = Map()
+    game_map.load_from_str("..... .### # ....# .")
+
+    assert game_map.map == [
+        [False for _ in range(5)],
+        [False] + [True for _ in range(3)] + [False],
+        [True] + [False for _ in range(4)],
+        [False for _ in range(4)] + [True],
+        [False for _ in range(5)],
+    ]
+
+
+def test_from_file():
+    game_map = Map()
+    game_map.load_from_file("game/tests/test_map.txt")
+
+    assert game_map.map == [
+        [False for _ in range(5)],
+        [False] + [True for _ in range(3)] + [False],
+        [True] + [False for _ in range(4)],
+        [False for _ in range(4)] + [True],
+        [False for _ in range(5)],
+    ]
+
+
+def test_from_arg_and_from_file_are_identical():
+    game_map_from_arg = Map()
+    game_map_from_arg.load_from_str("..... .### # ....# .")
+
+    game_map_from_file = Map()
+    game_map_from_file.load_from_file("game/tests/test_map.txt")
+
+    assert game_map_from_arg.map == game_map_from_file.map
diff --git a/game/tests/test_map.txt b/game/tests/test_map.txt
new file mode 100644
index 0000000..557cd49
--- /dev/null
+++ b/game/tests/test_map.txt
@@ -0,0 +1,5 @@
+.....
+.###
+#
+....#
+.
\ No newline at end of file
diff --git a/game/utils/map.py b/game/utils/map.py
index b12a17f..5e93ba3 100644
--- a/game/utils/map.py
+++ b/game/utils/map.py
@@ -94,14 +94,27 @@ def __str__(self) -> str:
     def load_from_str(self, map_grid: str):
         """
         Load the map from a string.
-        Use space for line breaks and # for alive cells.
+        Use space for end of row, . for dead cells and # for alive cells.
         """
         rows = map_grid.split(" ")
+        self.load_from_rows(rows)
+
+    def load_from_file(self, file_path: str):
+        """
+        Load the map from a file.
+        Use line breaks for end of row, . for dead cells and # for alive cells.
+        """
+        with open(file_path) as file:
+            map_grid = file.readlines()
+            self.load_from_rows(map_grid)
+
+    def load_from_rows(self, rows: list[str]):
         self.number_of_rows = len(rows)
-        self.number_of_columns = len(rows[0])
+        self.number_of_columns = len(rows[0].strip())
         self.map = [[False for _ in range(self.number_of_columns)] for _ in range(self.number_of_rows)]
         for y, line in enumerate(rows):
-            for x, char in enumerate(line):
+            for x, char in enumerate(line.strip()):
+                print(x, y, char, line)
                 if char == "#":
                     self.map[y][x] = True
                 elif char != ".":