Assuming you are a cleric of the fire domain, some of your domain spells are arcane (i.e. Fireball). Do you have to roll for arcane spell failure when wearing armor? Or are these spells considered to be divine even though they are normally arcane?
Spell type doesn't come from the spell itself, but from the class casting the spell.
All cleric spells, even those from a domain, are divine spells when the cleric casts them.
That is correct. Arcane classes don't cast divine spells, and divine classes don't cast arcane spells. If you get a spell that is normally of the other type then you cast it according to the class that is casting the spell.
What everyone else said. If you're a cleric with domain spells (or an oracle with mystery spells), those spells are divine. If you're a wizard/sorcerer using expanded spellbook or something like that, those spells are arcane. And so on.
You can fluff it as the divine somatic components are simpler, generally just presenting your holy symbol or making a holy gesture, whereas the arcane ones are more difficult and complicated, albeit no longer in duration, and thus armor can make them fail.
You can fluff it as the divine somatic components are simpler, generally just presenting your holy symbol or making a holy gesture, whereas the arcane ones are more difficult and complicated, albeit no longer in duration, and thus armor can make them fail.
Um, I'm confused. You do know the "arcane" spells a cleric gets from their domain count as divine, and therefore don't have ASF, right?