You can decide what metamagic feats to add a spell when you cast it.
Prerequisite: Spellcraft 5 ranks.
Benefit: When you cast a spell prepared as a flexible spell, you can decide what metamagic feats to add to it at the time of casting. When you prepare a flexible spell, you must decide how many levels of metamagic you can add to it when you cast it. You must know a metamagic feat in order to add it to a flexible spell. A flexible spell uses up a spell slot one level higher than the spell’s normal level, plus the total number of levels you may use to add other metamagic feats when it’s cast.
Example: Micheal Trebliock is an 8th level bard with the Flexible Spell and Still Spell feats. He decides to cast a flexible stilled charm person as a 3rd level spell, and can do so without taking extra time to cast the spell.
Normal: Normally spellcasters who prepare their spells must decide what metamagic to add to a spell when it is prepared, and spontaneous spellcasters must take additional time when adding metamagic effects.