Whenever this creature attacks, another target creature you control gets +X/+0 until end of turn, where X is this creature's power.
Legal in
Pioneer, Modern, Legacy, Vintage, Commander, Oathbreaker, Brawl, Historic, Timeless
Rulings (6)
The value of X is determined only as Gruul Beastmaster’s triggered ability resolves. Once that happens, the value of X won’t change later in the turn even if Gruul Beastmaster’s power changes.
2019-01-25
If you choose for the creature to gain haste, it gains haste indefinitely. It won’t lose it as the turn ends or as another player gains control of it.
2019-01-25
If Gruul Beastmaster leaves the battlefield before its triggered ability resolves, use its power as it last existed on the battlefield to determine the value of X.
2019-01-25
Riot is a replacement effect. Players can’t respond to your choice of +1/+1 counter or haste, and they can’t take actions while the creature is on the battlefield without one or the other.
2019-01-25