Mus is a Basque betting game for two pairs. You (bottom) play with Maite (top) against Iker and Ane. First pair to 40 points wins.
40-card Spanish deck: 1–7, sota (10), caballo (11), rey (12). With 8 reyes on, every 3 is a king and every 2 is an ace.
Starting with the mano (leads this hand, wins all ties), each player says mus (I'd like to swap cards) or no mus (play now). If all four say mus, everyone discards 1–4 cards and draws new ones, then asks again.
In each lance you may paso (check), envido (bet 2 or more) or call órdago (bet the whole game). Facing a bet: quiero (accept), no quiero (decline — they take what was already agreed, at least 1, straight away), raise, or órdago. Either partner may accept for the pair.
Nobody shows cards until all four lances are done. Then each lance is settled in order: accepted bets go to the pair with the best hand; an unbet grande or chica is worth 1; the pair winning pares or juego also scores the value of both partners' hands. An accepted órdago is settled immediately and decides the game.