Metamagic
Instead of increasing the level used to power the metamagic spell, spellcasters gain a pool of spell energy from which they use to cast cantrips and fuel metamagic enhancements to spells. The amount of spell energy a spellcaster has is equal to 3 + their caster level times two + the ability modifier from the ability score that grants bonus spells. In addition, for each metamagic feat selected, the spellcaster gains one additional point of spell energy.In order to add the metamagic enhancement to a spell, the spellcaster must expend an amount of spell energy equal to the spell level increase. For example, when applying the maximize spell metamagic feat enhancement, the spellcaster must expend three points of spell energy.
Spellcasters may apply any amount of metamagic enhancements to their spells, but must pay the full cost for each enhancement. For example, when applying the quicken spell, silent spell and still spell metamagic feat enhancements to a spell, the spellcaster must expend six points of spell energy.