Slap Bet

Only 1 copy of Slap Bet may be on the battlefield at any time.
When Slap Bet enters the battlefield, each opponent (proceeding clockwise) may enter a slap bet with you. Whenever a player loses the game and is in a slap bet, the other engaged player may slap the loser.
If Slap Bet leaves the battlefield, all slap bets are off.