quote:
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A ring of spell storing contains up to ten levels of spells that the wearer can cast. Each spell has a caster level equal to the minimum level needed to cast that spell. As with a wand (see the Wands section later in this chapter), the user need not provide any material components or focus, or pay an XP cost to cast the spell, and there is no arcane spell failure chance for wearing armor (since the ring user need not gesture)
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I read this as saying you use it like a wand, that is :
quote:
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Wands use the spell trigger activation method, so casting a spell from a wand is usually a standard action that doesn’t provoke attacks of opportunity. (If the spell being cast, however, has a longer casting time than 1 action, it takes that long to cast the spell from a wand.
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That seem opretty straightforward to me.