Planequake 
Sorcery
Planequake deals X damage to each creature without flying and each planeswalker. If X is 10 or more, open the "Uncovered Cavern" plot booster.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyNOT LEGALvintageNOT LEGALcommanderNOT LEGAL