What it does
Outlast is an activated ability that lets you tap a creature (and pay a cost, often just mana) to put a +1/+1 counter on it. You can only activate it at sorcery speed—during your main phase with an empty stack—and the creature must be untapped to do it, since tapping is part of the cost.
The big misunderstanding is timing and tapping: because it taps the creature, you're trading attacking or blocking that turn for permanent growth. You can't use it at instant speed or in response to threats. Many Outlast creatures also grant a bonus to all creatures with counters on them, rewarding you for building a wide, counter-heavy board.
In Commander, Outlast is slow but resilient—it shines in grindy +1/+1 counter decks (Abzan), pairing well with proliferate and counter payoffs to scale over a long game.












