Mana Web | Magic: The Gathering
Formats Mana Web is Legal in
Official Oracle Text for Mana Web
Official Rulings for Mana Web
4/1/2008 : The lands that are tapped by Mana Web's ability don't produce mana as a result.
4/1/2008 : The opponent can tap his or her lands for mana in response to Mana Web's ability triggering.