Fan Casting Balancing Death's Books in Sort by Tropes

Essentially, this is getting the Grim Reaper (or some other soul collecting entity), to accept one life in exchange for another. It can be done through an offer or some kind of trick. If a person volunteers to be the replacement soul, it could be a Heroic Sacrifice, but it doesn't have to be. There is often some kind of Equivalent Exchange involved, if the reason one life has to be traded for another is to preserve some kind of balance. When characters find themselves in this situation, it is almost always the case that Someone Has to Die. If an exception is made, it's generally at the whim of the soul collector.