When does Protection from Good work against good-aligned PCs? I wasn't able to find this specific question, which leads me to believe I'm misinterpreting or overcomplicating something.
My confusion here is over when someone "counts as good" for effect like this. For instance, I know that a paladin's detect evil won't ping your standard evil commoner - only a cleric, paladin, or creature with 5+ HD will detect as evil.
I also know that for something like DR 5/evil, a creature has to have the [evil] subtype for its attacks to count as evil and overcome DR. Players have to use spells, fancy weapons, or certain class features to get that alignment component.
So if I have antagonists that cast protection from good, do they only get their deflection and resistance bonuses against PCs using spells and weapons with specifically good effects? Or if they're level 5+ and good-aligned, is their goodness "baked in" to the point where protection from good's bonuses come into play?
You count as good if your alignment is good. You don't have to 'ping' on detect good to qualify.
Your bad guys get the deflection/resistance bonus against anyone of good alignment.