
At the beginning of your upkeep, if there are four or more creatures on the battlefield, sacrifice this enchantment and destroy all creatures. They can't be regenerated.
Planar Collapse has 2 printings, first in Urza's Legacy (1999). EDHREC ranks it #18,254 among Commander cards. It appears most in Hanna, Ship's Navigator decks (71 on EDHREC). It has 3 official rulings.
Deck counts from EDHREC.
Cards that show up in the same decks on EDHREC.