Sorcery, 5B (6)
Uncommon
Corrupt deals damage equal to the number of Swamps you control to target creature or player. You gain life equal to the damage dealt this way.
There are things beneath the murk for whom the bog is a stew, a thin broth in need of meat.
Illus. Dave Allsop

10/4/2004: The swamps are counted on resolution.
8/15/2010: The life you gain is equal to the damage dealt by Corrupt, not necessarily to the number of Swamps you control (if some or all of the damage is prevented, for example).
8/15/2010: The amount of damage dealt to a creature is not bounded by its toughness, and the amount of damage dealt to a player is not bounded by that player's life total. For example, if Corrupt deals 6 damage to a 2/2 creature, you'll gain 6 life.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Extended (Type 1.X)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern