OPEN is a climbing and shedding game in which each person plays with four of their six cards face up on the table.
At the start of each hand, players make a secret bet on which player they think will play all of their cards first. Points are awarded to all players but the last to go out. Points are also awarded to players who accurately predicted who would go out first.
Rounds are played until one player reaches a given score, then the player with the most points wins.
More Information: Link