Hecatomb | Magic: The Gathering
Formats Hecatomb is Legal in
Official Oracle Text for Hecatomb
Tap an untapped Swamp you control: Hecatomb deals 1 damage to target creature or player.
Official Rulings for Hecatomb
10/4/2004 : The sacrifice is done as a triggered ability just after it enters the battlefield. It is not done on casting.
10/4/2004 : You choose whether to sacrifice creatures or not on resolution. If not, then you sacrifice Hecatomb. You can choose to not sacrifice creatures if you no longer control this card on resolution.