Fool's Gold (AA)

You cast this spell on one or more gold pieces, which make those who have them more vulnerable to your magics. A creature with one or more of these gold pieces in its possession must attempt a Will save (at this spell’s save DC) the first time the creature is forced to attempt a saving throw against a spell, spell-like ability, or supernatural ability you create. If the creature fails, it takes a –2 penalty on all saving throws against your magic effects as long as the gold piece is in its possession. Additionally, if it fails a saving throw against a magic ability of yours that is not harmless and has a duration, the duration is doubled for that creature.