Historical Rules · 1 May 2012
Rule 509.1e
Official source text from the 1 May 2012 Rules release
If any of the costs require mana, the defending player then has a chance to activate mana abilities (see rule 605, "Mana Abilities").
Historical Rules · 1 May 2012
Official source text from the 1 May 2012 Rules release
If any of the costs require mana, the defending player then has a chance to activate mana abilities (see rule 605, "Mana Abilities").