SAVING THROWS AGAINST MAGIC ITEM POWERS
Magic items produce spells or spell-like effects. For a saving throw against a spell or spell-like effect from a magic item, the DC is 10 + the level of the spell or effect + the ability modifier of the minimum ability score needed to cast that level of spell. For example, a 2nd-level spell’s save DC would be 10 + 2 (for the spell being 2nd level) + 1 (for needing at least a 12 in the relevant ability score to cast a 2nd-level spell), or a total of 13.
Staffs are an exception to the rule. Treat the saving throw as if the wielder cast the spell, including caster level and all modifiers to save DC. For example, if Devis the bard triggers charm person from a staff of charming, it will have a save DC of 14 because Devis has a Charisma of 17. If Mialee the wizard triggers charm person from the same staff, it has a DC of 16 because her Intelligence score is 18 and she has the Spell Focus (enchantment) feat.
Most item descriptions give saving throw DCs for various effects, particularly when the effect has no exact spell equivalent (making its level otherwise difficult to determine quickly).
