Nightfall: Crimson Siege is an expansion for the deck-building game Nightfall, a game in which players draft Minions that they then send to attack and inflict wounds upon their opponents. Nightfall: Crimson Siege takes players to the final stronghold in Europe where humanity makes its last stand at the Vatican. Some familiar faces return to help the weary souls as they fortify the city and await the hordes of ghouls to come. Crimson Siege adds 24 minion cards (eight copies of each) and 30 "Summon" cards to Nightfall. Summon cards are a new card type in a standalone deck that allows players to summon more minions into play than ever before. Whenever a card with "Summon X" on it resolves its ability, you draw from the top of that deck and place a minion into play under your control. A variety of Ghouls are in the summon deck, and unlike other minions in Nightfall, when a Ghoul is destroyed, exiled, or otherwise removed from play, it goes back into the summon deck. Thus the supply of Ghouls to overwhelm your opponents will never run out!