Triggered abilities that trigger on blockers being declared may have different trigger conditions.
May 3, 2019 · War of the Spark
Third, for each blocking creature, the defending player announces that creature’s damage assignment order, which consists of the creatures it’s blocking in an order of that player’s choice. (During the combat damage step, a blocking creature can’t assign combat damage to a creature it’s blocking unless each creature ahead of that blocked creature in its order is assigned lethal damage.) This turn-based action doesn’t use the stack.
January 25, 2019 · Ravnica Allegiance
Third, for each blocking creature, the defending player announces that creature's damage assignment order, which consists of the creatures it's blocking in an order of that player's choice. (During the combat damage step, a blocking creature can't assign combat damage to a creature it's blocking unless each creature ahead of that blocked creature in its order is assigned lethal damage.) This turn-based action doesn't use the stack.
February 1, 2014 · Born of the Gods
Third, for each blocking creature, the defending player announces that creature’s damage assignment order, which consists of the creatures it’s blocking in an order of that player’s choice. (During the combat damage step, a blocking creature can’t assign combat damage to a creature it’s blocking unless each creature ahead of that blocked creature in its order is assigned lethal damage.) This turn-based action doesn’t use the stack.
September 30, 2011 · Innistrad
Third, for each blocking creature, the defending player announces that creature's damage assignment order, which consists of the creatures it's blocking in an order of that player's choice. (During the combat damage step, a blocking creature can't assign combat damage to a creature it's blocking unless each creature ahead of that blocked creature in its order is assigned lethal damage.) This turn-based action doesn't use the stack.
June 17, 2011 · Commander 2011
Third, for each blocking creature, the defending player announces that creature’s damage
April 1, 2011 · Duel Decks: Knights vs. Dragons
Third, for each blocking creature, the defending player announces that creature's damage assignment order, which consists of the creatures it's blocking in an order of that player's choice. (During the combat damage step, a blocking creature can't assign combat damage to a creature it's blocking unless each creature ahead of that blocked creature in its order is assigned lethal damage.) This turn-based action doesn't use the stack.
February 4, 2011 · Mirrodin Besieged
Third, for each blocking creature, the defending player announces that creature’s damage assignment order, which consists of the creatures it’s blocking in an order of that player’s choice. (During the combat damage step, a blocking creature can’t assign combat damage to a creature it’s blocking unless each creature ahead of that blocked creature in its order is assigned lethal damage.) This turn-based action doesn’t use the stack.
October 1, 2010 · Scars of Mirrodin
Third, for each blocking creature, the defending player announces that creature’s damage
February 1, 2010 · Worldwake
Third, for each blocking creature, the defending player announces that creature's damage assignment order, which consists of the creatures it's blocking in an order of that player's choice. (During the combat damage step, a blocking creature can't assign combat damage to a creature it's blocking unless each creature ahead of that blocked creature in its order is assigned lethal damage.) This turn-based action doesn't use the stack.