Do general deflection modifiers (such as a ring of protection) to AC stack with specific deflection modifiers (such as +1 AC vs. animals) when facing that specific type of foe? I don't believe they do, but a definitive answer would be much appreciated.

Only if it's dodge AC, which it will likely never be.

Deflection ac never stacks with deflection ac.

The only type of ac that stacks with itself is dodge.

But you could have one deflection

One natural armour

One shield

and one armour ac

those would all stack to +4 ac!

That's exactly what I thought, but I didn't want to drop items before I knew for sure. I'm aware of the natural/deflection/armor/shield/dodge difference, but those specific bonuses sometimes make me wonder. Thanks a bunch!!