Lovecraft Letter

To set up, each player receives a reference card. The 'Stowaway Eggs' card is found and set aside face up. The remaining 26 cards are shuffled, and the top card is set aside face down, not to be used this round. Finally, one card is dealt to each player as their starting hand. The player who most recently solved a mystery goes first.

The game is played over a series of rounds where players play cards to investigate an Eldritch mystery. The goal is to collect clues while maintaining sanity, or by embracing the horror, to win rounds. The first player to collect two sane Mythos tokens or three insane Mythos tokens wins the game.

A turn begins by drawing a card from the deck into your hand, giving you two cards. You then choose one card to play. Cards have either 'sane' effects (Arkham cards) or both 'sane' and 'insane' effects (Other World cards). By default, you start sane. If an Other World card is played or appears in your discard zone, you become insane. When playing a card, you use the effect corresponding to your current state of mind. If you are insane and the card does not have an insane effect, you use the sane effect. After playing and using the card's effect, you discard it face up into your discard zone, which remains visible to all players. If you are insane before drawing a card, you must make a sanity check by revealing cards from the deck equal to the number of Other World cards in your discard zone. If any revealed card is an Other World card, you fail, are out of the round, and discard your hand. If all revealed cards are Arkham cards, you pass and continue your turn as normal. Revealed cards are placed in your discard pile. If 'The Dilettante' or 'Cthulhu' (both 8-value cards) are discarded from your hand for any reason, you are out of the round.

A round ends when only one player remains, making them the winner, or when the deck runs out. If the deck runs out, all players compare the cards in their hand, and the player(s) with the highest value card win the round. The winner of the round takes a Mythos token corresponding to their state of mind: a blue brain token for sane or a green tentacle token for insane. Your state of mind is determined by whether you have any Other World cards in your discard zone (insane) or only Arkham cards (sane).

The game concludes when a player accumulates two sane Mythos tokens or three insane Mythos tokens. If no player has met these conditions after a round, all cards are collected, shuffled, and a new round begins with setup as described, except the 'Stowaway Eggs' card remains set aside. If playing with two players, after initial setup, draw five additional cards from the deck and set them aside face up; these cards are not used in the round but provide information about what cards are out of play.