Calculating APL with NPC companion

[Ogadim]

Since two of our regular players will be leaving for the holidays, instead of continuing our current campaign we have postponed it in favor of a one-shot scenario that I am designing. We have yet to play with the Mythic rules, so this seemed a fun way to try out the new features.

My issue is this: we will only have 3 PC characters (Level 13 with 6 Mythic tiers) and I wanted to add a Mythic Hill Giant companion for story purposes and to make fights a bit more exciting. The Mythic Hill Giant is a CR9/MR3 monster, and I'm having trouble figuring out how to factor it into the group's APL so that I can properly ballpark their encounters.

My current calculations for the group would have them at an APL of 15 ([39 for levels + 9 for mythic tiers]/3 - 1 for only 3 players). When adding this Mythic Hill Giant companion, how much should I adjust the APL to compensate?

[blahpers]

A PC normally has its own level as its CR, so by that math the hill giant would count as level 9 for the APL calculation. The hill giant's mythic rank is already factored into its CR.

That said, CR is not a great indicator of party utility, and there aren't any rules for including NPCs in APL calculations as far as I know, so anything at this point is winging it.

[Ogadim]

blahpers wrote:

A PC normally has its own level as its CR, so by that math the hill giant would count as level 9 for the APL calculation. The hill giant's mythic rank is already factored into its CR.

That said, CR is not a great indicator of party utility, and there aren't any rules for including NPCs in APL calculations as far as I know, so anything at this point is winging it.

Yeah I was having trouble finding a corollary in the rules. If the CR is already factored in, then maybe I'll have a pair of Mythic Hill Giants join them and have some exiled brothers story thrown in. I guess I'll just go with their experience level if they themselves were an encounter and treat them as 1 PC for the APL.

2 CR 9 creatures would be 6,400 XP each which combines to the equivalent of a CR 11 monster. Adding that to the current APL would keep it approximately the same, so I'm just going to wing it like you suggest and say they're around 15-16 APL. The PCs are still the majority of the contribution, but it will help having extra bodies in case 1 PC gets incapacitated which could easily wreck an encounter.