At the beginning of your end step, if Erg Raiders didn’t attack this turn, Erg Raiders deals 2 damage to you unless it came under your control this turn.
A creature "comes under your control" if it enters the battlefield under your control or if you gain control of it while it's already on the battlefield.
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.