
pipedreamsam |

I was reading the huge synthesist summon thread and after awhile I did not find the answer to this particular question so I just stopped. If this question has already been addressed and answered my apologies in advance.
Does the bab from the synthesist (whilst in eidolon form) and the bab from other classes stack?

pipedreamsam |

It's in the FAQ, I don't feel like looking it up right now, but yes it does. It works the same way Flurry BAB does (meaning it only counts for the class that grants it, other classes are added to it normally.)
A Synthesist 1, Fighter 19 has BAB 19 normally and BAB 20 fused.
Thank you so much, finally a way to make a viable summoner/dragon disciple.

Melkiador |
1 person marked this as a favorite. |

https://paizo.com/paizo/faq/v5748nruor1fz#v5748eaic9obc
The synthesist uses the eidolon's Hit Dice for the effects of evolutions, not his summoner Hit Dice or his total Hit Dice.
When fused, use the eidolon's BAB instead of the summoner's class BAB, and add in BAB from other sources as normal. For example, a fighter 19/summoner 1 normally has a total BAB of +19 (+19 from fighter, +0 from summoner), and when fused with his eidolon this increases to +20 (+19 from fighter, +1 from the 1st-level eidolon).