A friend and i was talking about commander. We didnt know is this was possible but well just say it is. If you give your commander undying. When he would leave the graveyard by being destroyed would he stay with a 1/1 counter or go back to the commander zone? I say back to the commander zone he thinks it gets a counter. Which is correct?

I havent really played commander before and just started getting into it.

I'm pretty sure the rules are that it's up to you whether you want your commander to hit the GY or to be exiled to the command zone instead.

I could see a few reasons to want to exile instead of getting the counter though, if someone's got an instant-speed card to shuffle your GY into your deck, or to take a creature card from any GY and put it into play under their control. Those can be played as a response to the undying trigger, so they happen before your commander gets reanimated.

Nighthawk wrote: I'm pretty sure the rules are that it's up to you

Yes, that's correct:

903.11. If a commander would be put into its owner’s graveyard from anywhere, that player may put it into the command zone instead.

Note, the player may put it into the command zone. They don't have to if they don't want to.

Ok thanks