One Halloween eve, vampires, ghosts and other monsters decide to get together around a succulent feast. As the organiser of one of these parties, you must make sure that only the most prestigious guests attend, whilst ensuring that the unwanted ones go off to your opponents.

At the beginning of the game, each player receives two monster cards. These are placed in front of the players and are the first guests. Players are then dealt fi ve cards each to form their hand. The remaining cards are left as a deck in the centre of the table. On their turn, each player will offer a card to an opponent, face down, while saying, Knock, knock?!. The latter can either accept or refuse the offered card. If the card is accepted, the player takes it and applies its effects. If the card is refused, then the player who offered it must add it to their own guests. The active player then draws a new card to bring their hand back up to five.

The game ends when the deck has run out and all the players have played their hand cards. Now the players? scores are calculated. Each monster, vampire or ghost is worth one point, musicians double the points gained for their type of guest, and scarecrows are worth three points. The winner is the player with the most points.