[RPG] How to tell how many damage dice to roll for an NPC’s cantrip


For PCs, cantrip damage increases with their total character level and not their class level (see this question for reference: Do Cantrips use your character level or class level?).

However, NPCs do not normally have class levels, and their stat blocks don't state a total character level.

How can I determine the number of damage dice to roll for an NPC's cantrip?

  1. Should I use their number of hit dice as their total character level?
  2. Should I use their stated Spellcaster level? (What if they don't have one?)
  3. Some other method?

A couple of examples to illustrate my concern:

  • An Archmage (SRD p. 395) has 18d8 + 18 hit dice and is an 18th-level spellcaster, so methods 1 & 2 here would produce the same result.

  • Nezznar the Black Spider (LMOP p.59) has 6d8 hit dice and is a 4th-level spellcaster, so methods 1 & 2 would produce different results.

    The fact that Nezznar has more hit dice than spellcasting levels implies to me that Nezznar has, in some unspecified way, multiclassed – and that 6 would be his total character level – and the number I should use for cantrips, not 4 (his spellcasting level).

A good answer would also cover NPCs with Innate Spellcasting and no spellcasting level. See, for instance:

  • A Green Hag (SRD. p 319) has 11d8 + 33 hit dice but no spellcasting level listed.

Best Answer


For the Spellcasting trait, you use the listed spellcaster level as read on page 10 of the Monster Manual:

The spellcaster level is also used for any cantrips included in the feature.

This means an archmage is treated as level 18 for the purposes of cantrips, and Nezznar is treated as level 4 (despite his greater number of hit dice).

Innate Spellcasting

Innate Spellcasting will sometimes list a specific level (in which case use that one), but otherwise you use the monster's CR (as also stated on page 10 of the Monster Manual):

If a monster has a cantrip where its level matters and no level is given, use the monster's challenge rating.

For the green hag, this means it is treated as level 3 for its cantrips.