This is a technical question and I'd like to make sure I'm not reading the rules wrong before I take the plunge with my character.
She's a sorceress with one dip into oracle, so she's proficient with most shields and also medium and light armor, playing in PFS organized play. I was considering getting her a mithril buckler and a mithril chain shirt after taking the arcane armor training feat at 5th level. This sounds to me like she'd have a 0% arcane spell failure chance:
Chain shirt = 20% arcane spell failure chance, -10% for mithril, -10% for arcane armor training = 0 arcane spell failure chance
Buckler = 5% arcane spell failure chance, -10% for mithril = 0 arcane spell failure chance.
What's throwing me a bit is the rule on page 150 of the CRB that says when you're using both a shield and armor, you add the spell failure chances together, in this case for 20% for the shirt and 5% for the shield, for a total spell failure chance of 25%. In that case, would you still be left with a 5% failure chance-- 25% for shirt + shield, -10% for arcane armor training -10% for mithril = 5% arcane spell failure chance.
I guess what it comes down to is this--is the -10 arcane spell failure chance for mithril, specified on pages 154-155 of the CRB, applied twice--once for the shield and once for the body armor, or is it applied once to the cumulative arcane spell failure chance of the shield plus the armor?
The more liberal reading makes sense to me, but as we all know, that often doesn't make much difference if you're sitting at a table with a more restrictive DM. I'd like get some idea of the consensus before I make the move with my character.
Thanks.
