diff --git a/app.py b/app.py
index 6e06daa..45e86c9 100644
--- a/app.py
+++ b/app.py
@@ -39,7 +39,7 @@ def init_random_game():
 @app.route('/init/deterministic', methods=['post'])
 def init_deterministic_game():
     game_id = request.form.get('game_id')
-    if not game_id.isdigit() or not 0 < int(game_id) < NUM_GAMES:
+    if not game_id.isdigit() or not 0 <= int(game_id) < NUM_GAMES:
         flash("game_id must be between 0 and {}".format(NUM_GAMES))
         return redirect(url_for('home'))
     return redirect(url_for('init_deterministic_game_id', game_id=game_id))