Does undying trigger if a creature with a +1/+1 counter is destroyed?

Undying reads: "When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it." The presence of even a single +1/+1 counter on the creature at the moment it dies completely prevents undying from triggering.

This is governed by CR 702.92a, which defines undying, and CR 700.4, which clarifies that "dies" means a creature moving from the battlefield to the graveyard. The game checks the creature's state as it last existed on the battlefield — specifically whether it had any +1/+1 counters — to determine if undying's condition is met (CR 603.10).

It's important to note that +1/+1 counters and -1/-1 counters do annihilate each other in pairs (CR 121.3), so if a creature had both types, they cancel out first. But if any +1/+1 counters remain after annihilation, undying will not trigger.

Example: You control a Strangleroot Geist (which has undying). An opponent uses Increasing Savagery to put five +1/+1 counters on it, then destroys it with a removal spell. Because Strangleroot Geist had +1/+1 counters on it when it died, undying does not trigger and it stays in the graveyard.