Prererequisite: Any metamagic feat, Ability to cast 3rd level arcane spells
Mana burn is a feat that enables the caster to generate extra spell slots at the expense of her physical health. A Wizard will be able to select any spells she has memorized and then to select any number of slots desired.
For every spell slot over her normal limit, she must sacrifice 1d4 hitpoints per level of spell. The caster can convert hit-dice into spell levels for the purpose of powering extra spells. Thus, if a wizard wished to prepare 3 more Flaming Sphere spells than she is able to memorize, she may tap into her health to create additional slots, suffering 2d4 points of damage to generate a second level spell slot each time she casts a Flaming Sphere above her limit. If she wished to prepare an extra Ice Storm spell, she would suffer 4d4 damage every time she cast this spell above her limit. A wizard must determine exactly which spells to prepare in this method, and how many extra slots she wishes to allow herself beforehand; All potential uses of this ability must be declared by the player of a wizard during spell preparation. A sorceror could use this feat with any spells in his repetoire. Any hit points lost at the start of the day may not be recovered by healing in any form. It is as if the caster has permanent less hitpoints for that day.
This adds to the suspense of a close battle by permitting a mage to be a powerful force for a longer time, but the random loss of hitpoints adds an element of risk and uncertainty; heightening the excitement.
This feat also is suggestive of a higher level feat; Improved Mana Burn, which would change this damage to subdual damage. Improved Mana Burn will have the extra prerequisite of two other meta-magic feats aside from original Mana Burn and the ability to cast 5th level arcane spells.