House of Doom 2: The Crypt is a 5 by 3 video slot game with 20 paylines. The game has different themes which affect the appearing WILD symbols in base game, the music and the FREE SPINS feature. The theme changes randomly into a different one after a FREE SPINS or CRYPT SPINS feature has ended. QUEEN OF THE DAMNED, FIRE MISTRESS, and METAL PRIESTESS themes are indicated by green, purple, and blue backgrounds respectively.

During the base game, SPIRIT GATE can randomly appear on any reel. The active WILD during SPIRIT GATE feature is random. If a WILD symbol lands in it, the WILD expands and triggers one re-spin with a special bonus feature, which does not include SCATTER symbols. Expanded WILD is held in place during the re-spin.

QUEEN OF THE DAMNED WILD symbol landing in SPIRIT GATE adds SPIRIT GATE to all reels for the re-spin. WILDS landing in SPIRIT GATES during re-spin also expand but do not trigger further re-spins.

FIRE MISTRESS WILD symbol landing in SPIRIT GATE awards a random MULTIPLIER for the re-spin, which can be one of x2, x3, x5 or x10.

METAL PRIESTESS WILD symbol landing in SPIRIT GATE turns all RITUAL RELIC symbols into SKULL symbol.

8 FREE SPINS can be triggered by 3 SCATTER symbols on reel 1, 3 and 5. In FREE SPINS there is only one type of bonus available, which is determined by base game theme. It is possible to have more than one SPIRIT GATES activated on each spin.

8 CRYPT SPINS can be activated through base game and FREE SPIN with 3 UPGRADED SCATTERS. UPGRADED SCATTERS can land when at least one SPIRIT GATE is active on any reel. CRYPT SPINS have a unique WILD called SPIRIT OF UNITY. Whenever SPIRIT OF UNITY lands in the SPIRIT GATE it awards a re-spin with FIRE MISTRESS, METAL PRIESTESS and QUEEN OF THE DAMNED bonus features on wins. Re-spins never trigger further re-spins. 3 UPGRADED SCATTERS can re-trigger CRYPT SPINS unlimited times.