One Finger! is a mind game in which players try to anticipate the others' reaction to win as many cards as they can... with only one finger.
A quick glimpse of a game round
Everybody put their finger down on a card
Active player calls a number and everybody lift their finger... or don't
Count the fingers... same number the active player wins a card, otherwise they don't :)
Immediacy, guessing, bluffing, laughing... you just need One Finger to have fun!