Gimme Five 
Instant
You gain 1 life for each person who high-fives you in the next thirty seconds. Each player in an Un-game who high-fives you gains 1 life. (Offer high fives. Don't hit people.)
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyNOT LEGALvintageNOT LEGALcommanderNOT LEGAL