[RPG] What makes a creature a Devil

dnd-5emonsters

Reading the Monster Manual section on Devils, it has a list of types of devil with their stat blocks and how they stand in a hierarchy. Since there is a hierarchy, is this a complete list of devils in the 5e game?

If I wanted to make a new creature that is a devil, what essential attributes would it have to have? It would have to be a Lawful Evil Fiend, but what else? What makes e.g. a Hell Hound or Rakshasa not a devil? Or are those creatures devils too?

Best Answer

A devil is formed/born when (MM 66, top paragraph)

sending his servants to the mortal realm to corrupt the souls from which new devils are spawned

So, answering about Rakshasas and Hell Hounds, they are each a unique fiend rather than being a form of corrupted mortal soul.

On the next page is a list of four main categories of devils, with a subsection called Promotion and Demotion covering how a corrupted soul can get from newly minted minion all the way up to the top levels of the Infernal Hierarchy.

In the stat blocks on MM 70-78, it appears that all Devils have the following features:

  • Resistance to: cold; bludgeoning, piercing, and slashing from nonmagical weapons that aren't silvered
  • Immunity to fire and poison
  • Immunity to the Poisoned condition
  • 120' darkvision
  • 120' telepathy
  • Infernal language
  • Magic Resistance

Most also have natural armor and Devil's Sight (for some reason, not Pit Fiends or Erinyes).

Making Your Own Devil

If you're making your own devil then the only real core is Lawful Evil and some kind of corruption of a mortal soul. I see two options to make it interesting.

First: Backstory.

A favored NPC is a literal devil in disguise. The drama arises from the emotional connection PCs have to this NPC. This is basically a literary classic.

In D&D terms, though, you might consider what happens differently when an Elf or Dwarf is corrupted, as opposed to a Human. The books don't seem to say anything on this, but it's totally within DM purview to build the world in this regard.

Second: Custom monster.

DMG 273 details how to create or modify a monster.

My favourite technique for this is covered in the Modifying a Monster section. Just take a different monster and describe it differently. A short step away from that is describing a creature differently and also tweaking small things like energy type on damage. For example, you could just take a Deva, give him red skin and horns, then tweak that Radiant damage to Necrotic. There's a section on Fallen Angels on MM P. 15 if you'd like to commit to this route.

If that's not enough, then use the subsequent sections to create your own. The most important step here is in the opening paragraphs: the concept. If you're sticking with the book's 'corrupted soul' concept, then consider what sins/corruptions might have created the various devils in the book. Then consider what your new creation's sin might have been (backstory again!) and what thematic powers, traits, and quirks might manifest. Add those to the above list of generic devil traits. Additionally, you should consider how this devil fits into the Infernal Hierarchy, including which devils owe it fealty and which it owes fealty to.