[RPG] a Living Creature

dnd-5e

What does D&D 5e define as a living creature? More specifically, which creature types would be considered not to be living? The only creature type I see that suggests nonliving is undead.

Page 7 MM:

Undead are once-living creatures brought to a horrifying state of
undeath…

The phrase "once-living" suggests that it is no longer a living creature, but what about Constructs, Elementals, Fiends, Celestials, etc.?

The Bag of Devouring directly mentions this on page 153 DMG:

Animal or vegetable matter placed wholly in the bag is devoured and
lost forever. When part of a living creature is placed in the bag, as
happens when someone reaches inside it, there is a 50 percent chance
that the creature is pulled inside the bag… Any creature that starts
its turn inside the bag is devoured, its body destroyed.

Given the mention of "living creature" as to what the bag specifically pulls in, and the additional mention of "Any creature" suggests that there are living and unliving creatures.

Best Answer

A living creature is a creature that is alive

Defining life is difficult, but recognizing it is pretty easy. You consider the creature in question and then go 'Is that alive?' and if the answer is 'Yes.' then it's yes, and if it's 'No.' then it's no and if it's 'Maybe?' then it's probably no for the purposes of D&D.

Beyond that, it comes down to souls. D&D acknowledges the soul as the seat of identity as well as life, and things that have souls are, generally, alive, while those that do not are not. The biggest category of exception are the undead who, in keeping with folklore, are neither truly dead nor truly alive, trapped in a hellish and unnatural state of being. Other exceptions can exist, and it's probably best to just go with your intuition on this one.

There's no 5e equivalent to the 3.5 rule about Constitution scores, if that's what you're looking for.