[RPG] What does getting ‘killed outright’ mean for Relentless Endurance


The Half-Orc race (PHB, page 41) has the Relentless Endurance trait, whose description states:

When you are reduced to 0 hit points but not killed outright, you can drop to 1 hit point instead. You can’t use this feature again until you finish a long rest.

But what exactly is meant by "not [getting] killed outright"? Can you only use this when the damage is ongoing damage that puts you at 0 hit points? When exactly does the Relentless Endurance trait activate?

Best Answer

If you read the "Dropping to 0 Hit Points" section of the PHB/basic rules, you'll find the following paragraph under "Instant Death":

Massive damage can kill you instantly. When damage reduces you to 0 hit points and there is damage remaining, you die if the remaining damage equals or exceeds your hit point maximum.

Thus, the "killed outright" that the Half Orc's racial trait is referring to here is overdamage equal to your Hit Point max.