What it does
Recover is a triggered ability on cards in your graveyard. When another creature you control dies, you may pay the recover cost to return the card with recover from your graveyard to your hand. If you don't pay (or can't), the card with recover is exiled instead.
The most common mistake is thinking recover triggers off its own creature dying or off any creature—it only triggers when another creature you control dies, and only while the recover card is already in your graveyard. Also, declining to pay isn't free: the card gets exiled, so you can't keep it around indefinitely waiting for a better moment.
In Commander, recover rewards sacrifice and aristocrats decks that constantly churn creatures, letting spells like Penumbra Spider or Twisted Abomination loop back. Just weigh the exile risk—if you can't afford the cost when it triggers, you lose the card permanently.






