Contamination | Magic: The Gathering
Formats Contamination is Legal in
Official Oracle Text for Contamination
If a land is tapped for mana, it produces instead of any other type and amount.
Official Rulings for Contamination
10/4/2004 : External effects that generate more mana still generate their additional mana as directed without being affected by this card. Effects which generate more mana based on what type of mana the land produces will be affected in color but not in amount.
10/4/2004 : You choose whether to sacrifice a creature or not on resolution. If not, then you sacrifice Contamination. You can choose to not sacrifice even if you no longer control Contamination on resolution.