War's Toll

Oracle Text

Whenever an opponent taps a land for mana, tap all lands that player controls.

If a creature an opponent controls attacks, all creatures that opponent controls attack if able.

Card Rulings

5/1/2006 Your opponent can tap lands for mana in response to the triggered ability. The effect won’t prevent your opponent from casting spells or activating abilities, but it will make it difficult for that player to cast other spells or activate abilities later in the turn because players’ mana pools empty at the end of each step.