diff --git a/src/game.clj b/src/game.clj
index cd32e03..29e947e 100644
--- a/src/game.clj
+++ b/src/game.clj
@@ -8,3 +8,6 @@
 
 (defn add-player-of-game [state game player]
   (update-in state [:games game] #(conj % player)))
+
+(defn remove-player-of-game [state game player]
+  (update-in state [:games game] #(disj % player)))
diff --git a/test/game_test.clj b/test/game_test.clj
index 39b6c55..1706c94 100644
--- a/test/game_test.clj
+++ b/test/game_test.clj
@@ -18,3 +18,8 @@
   (is (=
        '#{"player-one" "player-two" "player-four"}
        (get-in (add-player-of-game test-state :quasi-rts "player-one") [:games :quasi-rts]))))
+
+(deftest remove-player-of-game-test
+  (is (=
+       '#{"player-one" "player-three"}
+       (get-in (remove-player-of-game test-state :imaginary-rpg "player-four") [:games :imaginary-rpg]))))