False Floor 
Artifact
This artifact enters tapped.
Creatures enter tapped.
, 
, Exile this artifact: Exile all untapped creatures. Activate only as a sorcery.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL