Jackstab

In this modern take on 21 (think Liar's Dice meets Blackjack), you and up to six other pirates vie for the highest bounty without going overboard. Begin the game by placing one card from your hand facedown as your "Jack." This card adds 10 to your bounty, no matter its true value. But be careful - if it's not a real Jack, it can get stabbed! Take turns bluffing, boasting, and stabbing each other in the "Jack" until only one player remains!

—description from the designer