I'm building a lv1 Sintetist and I've some doubts about the saving throws. When I've to use my ST and when my eidolon's ST?
For example:
1) an enemy wizard cast a fireball: Have I to use my ST or my edidolon' s ST? And then only my eidolon loose HP?
2) an enemy wizard cast charm on me: Have I to use my ST, my edidolon' s ST or it works on both and I've to save both of us? What happens if my eidolon exceed the St and me no?
3) the usual wizard cast finger of death on me: What happens?
I hope that my english is not too bad...
1) Your own saving throw, modified according to your new stats when fused.
2) Your own saving throw, and there is no eidolon to be charmed; only you.
3) Make your own saving throw, modified according to your new constitution modifier when fused.
ok thanks, and what happens if I wear a cloack of resistance? Have I a bonus on my ST or is the eidololon who have to wear it? Can my eidolon wear an armor?
Here is the key to the synthesist: When you became one, you killed your eidolon. It no longer exists as a separate being. All you have is the remnants of its power- its ability scores, its evolutions etc- which you have fused onto yourself. There is no separate eidolon with its own saving throw, there is no separate eidolon to wear its own equipment.
And when fused you cannot wear armor as eidolons cannot wear armor.
I suggest reading the Systhesist archetype thoroughly again. The Synthesist always uses his own base saves. However his Fortitude save is modified to his "eidolon suit"s Con value, which may change the bonus, otherwise saves remain the same (until later levels ;P)
Think of the eidolon as a set of special armor (it also replaces any armor the synthesist might be wearing when it is summoned). The eidolon itself can never wear armor: this is unchanged from base summoner rules.
The synthesist has many extra rulings which make it quite a tricky archetype to play and a bit of a headache for GMs. I suggest looking into this alternate synthesist which "fixes" some of the problems with the synthesist. Since synthesist is illegal pretty much everywhere ask your GM nicely to use this more streamlined and easier to handle version.