You may exert Battlefield Scavenger as it attacks. (It won’t untap during your next untap step.)
Whenever you exert a creature, you may discard a card. If you do, draw a card.
If you gain control of another player's creature until end of turn and exert it, it will untap during that player's untap step.
18-04-2017
wotc
If an exerted creature is already untapped during your next untap step (most likely because it had vigilance or an effect untapped it), exert's effect preventing it from untapping expires without having done anything.
18-04-2017
wotc
Some cards have abilities that trigger whenever you exert any creature. These abilities trigger when you exert that creature or any other creature you control.
18-04-2017
wotc
You can't exert a creature unless an effect allows you to do so. Similar effects that "tap and freeze" a creature (such as that of Decision Paralysis) don't exert that creature.
18-04-2017
wotc
All cards in the Amonkhet set that let you exert a creature let you do so as you declare it as an attacking creature, as do some of the cards in the Hour of Devastation set. You can't do so later in combat, and creatures put onto the battlefield attacking can't be exerted. Any abilities that trigger on exerting an attacking creature will resolve before blockers are declared.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.
Dan Murayama Scott2017-04-28
