If a cost includes a mana payment, the player paying the cost has a chance to activate mana abilities. Paying the cost to cast a spell or activate an activated ability follows the steps in rules 601.2f–h.
October 1, 2010 · Scars of Mirrodin
Damage dealt to a player normally causes that player to lose that much life. See rule 119.3.
July 16, 2010 · Magic 2011
Damage dealt to a player causes that player to lose that much life.