First Strike is an activated ability that allows a creature to make its counterattack before it recieves damage from an attacking creature. First strike is only activated in situations in which a creature can make a legal counterattack.
Bobby moves his Black Knight next to his opponents' White Knight and makes a melee attack. Instead of recieving 20 damage from the black knight and being destroyed, the White Knight's First Strike ability activates and it is allowed to deal it's attack first. Bobby's Black Knight takes 20 damage and dies before it can damage the White Knight.
Notable cards that use First StrikeEdit
MTG: TCG Player AnalysisEdit
First Strike in MTG:TCG operated by allowing a creature to deal it's damage in a round first irregardless if it was attacking or defending. This meant that an attacking creature had to be blocked by another creature large enough to both take the blow and to deal damage to the attacking card. In Magic The Gathering Tactics, the First Strike ability only activates when a creature is being attacked, making it a purely defensive ability.