Unlike a `Pearl of Power` when you have a 15% chance to fail how does this work?
Unlike a `Pearl of Power` when you have a 15% chance to fail how does this work?
Not quite sure what you're asking here.
Casting a spell requires a spell failure check. Using a magic item does not, with the probable exception of Spell Completion items (ie Scrolls). Since they are treated as though you were casting the spell, including "final gestures, words and so on," I would say that Arcane Spell Failure applies. Spell trigger, command word and use activated items should not require an ASF check since no somatic components are required.
Using a Pearl of Power allows you to recall a spell that has already been cast, essentially re-preparing it for you. Using the pearl thus does not require an ASF check, but once you go to cast the spell that it recalled, you would have to.