diff --git a/server/db/migrations/004_cards_category.sql b/server/db/migrations/004_cards_category.sql
new file mode 100644
index 0000000..c9a5edc
--- /dev/null
+++ b/server/db/migrations/004_cards_category.sql
@@ -0,0 +1,17 @@
+-- Extend the games.category CHECK constraint to include 'cards'.
+-- SQLite requires table recreation to change a CHECK constraint.
+
+CREATE TABLE games_new (
+  id INTEGER PRIMARY KEY AUTOINCREMENT,
+  slug TEXT NOT NULL UNIQUE,
+  name TEXT NOT NULL,
+  category TEXT NOT NULL CHECK (category IN ('tabletop', 'casino', 'word', 'cards')),
+  max_players INTEGER NOT NULL DEFAULT 2,
+  supports_multiplayer INTEGER NOT NULL DEFAULT 1
+);
+
+INSERT INTO games_new SELECT * FROM games;
+
+DROP TABLE games;
+
+ALTER TABLE games_new RENAME TO games;