Artifact, 4 (4)
Uncommon
At the beginning of each opponent's upkeep, Skullcage deals 2 damage to that player unless he or she has exactly three or exactly four cards in hand.
Only a focused mind can survive it.
Illus. Ron Spencer

12/1/2004: Skullcage's ability deals damage if the player has zero, one, two, five, or more than five cards in hand when its ability resolves.
12/1/2004: Skullcage doesn't check hand size when it triggers, only when it resolves.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern