Magical rings must be worn on a creature's primary digit to use their magic. Humanoids with two "hands" have two primary digits (one for each hand, determined at random). Magical rings will resize to fit any creature.
When donned, a magical ring will transmit it's method of commanding the magic to its wearer. Thus, knowing the powers of a ring will be immediate unless the description indicates otherwise.
Dwarves/Gnomes/Halflings. A dwarf, gnome, or halfling that dons a magic ring will have a chance of the ring malfunctioning. See their description in Character Races. Cursed rings that do not function when donned may be removed and the curse broken for that individual.
Caster Level All rings function at Caster Level 12 unless stated otherwise.
Casting Time Many magical rings operate continuously. Those requiring an action to bring about an effect are treated as invocations unless noted otherwise.
Range An effect centered on the wearer is "0"; Otherwise other effects will list a range (similar to spells).
Area of Effect See Casting Spells.
Duration See Casting Spells.
Save See Casting Spells.
Aura The notation is used for detect magic effects (priest-cast detection is larger grained than magic-user): [priest]/[magic-user]
Class Requirement If only certain character classes can use the item, it will be noted here. Creatures without character classes typically cannot use items meant for a specific character class (per the GM).
Encumbrance Worn rings have no encumbrance.
Charges Most rings do not use charges, but those that do will be noted.
XP Value/GP Value These are the requisite values for whole and fully charged items. If partially used, the values are at the remaining ratio. See also XP for Treasure and Magic Items.
Effects If a spell effect is indicated, it will be a mage spell, or, if not a mage spell, a cleric spell (unless the spell-type is indicated).
Unless described otherwise, items that require attunement may be removed by the attuned possessor without losing the attunement for up to 24 hours (unless the item is attuned by another).