Shared Death

This is only concerning playable characters in multiplayer games. The crux of the idea is a human player suffers death penalty for another human player's failure to remain alive.

Usually in this case, one or more secondary playable characters has access to extra lives but these only matter so long as the main playable character does not loose their extra lives. The secondary playable character can die without ending the game for the primary playable character. Or the secondary playable character may even have infinite lives. But it can also occur that any playable character running out of lives can kill the rest. This can be a case of shared lives but the pool of lives exists only while certain playable characters continue to live.

In cases of RPGs, the death of the main character may end the game even if all the other playable party members are perfectly healthy, equipped, and capable of beating the game. Also, if the game has resurrections of any sort, the other playable party members could have brought the main character back if their death was not instead a forced game over. Does not apply in cases of mission/story failure linked to the main playable character's death. Might not apply if the story is framed as the main character's viewpoint.

Might be related:
We Cannot Go On Without You