Blood Magic

[Bampf]

Found this home-brewed feat online for 3.5 and want to get input on it's perceived level of balance. I was thinking about changing the damage to 1d8 per spell level and/or capping it to one or two levels.

Prepared spell casters would have to decide to prepare a blood magic spell ahead of time but would not take the damage until the spell is cast.

Blood Magic [Magical Feat]
Prerequisite: Must be capable of casting 2nd level spells
Benefit: After gaining this feat a spellcaster may boost their spells by adding a blood component to the casting. As a part of the casting the caster may choose to deal 1d6 damage to itself and add 1 spell-level to the spell. This can be used to reduce the cost of metamagic feats, or to allow the caster to utilize a spell without giving up the spell slot for the day. The damage increases by 1d6 for every spell-level added.
Normal: Casters are normally restricted to their own spellslots for castings.

Thoughts?

[Vrecknidj]

As written, I think it's too powerful. And, rather than scaling up from 1d6 to 1d8, I would think something more detrimental, like Con damage, would do the trick. Perhaps a chain of feats...

Blood Magic
Prerequisite: Any metamagic feat
Benefit: You may cast a spell using any metamagic feat you know and do so without paying the full spell level slot cost. For every spell level slot you ignore, you suffer 1 point of Constitution damage. (For example, casting a Quickened Fireball as a 3rd level spell requires you to suffer 4 points of Constitution damage.) You do not suffer this damage when memorizing the spell (though it takes up the lower-level slot); you suffer it only when you cast the spell.

There are a few reasons I think this. First, as you lower your Constitution, you suffer a loss of HP, but also accept lower Fort saves. Second, it gives you a fair bit of flexibility (if you have an even Con score, you can get away with tweaking a single-level-slot feat once and not worry about it). Third, it offers feat ideas for the chain.

An improved version might reduce time you suffer the ability damage. Also, you could have another variant that allowed you to tweak spells in yet other ways that also caused the same kind of cost.

[Bampf]

More predictable consequences of casting but more on par with the powerful effect of the feat. Don't think PC's would take it as written but could be interesting for some NPC's. At that point though it could be considered too powerful in the wrong direction. I like where you took it though.

[Necromancer]

You should check out the taint variant rules and Blood Components.

[Tark of the Shoanti]

Mongoose Publishing made a Blood Magic book a while back in the Encyclopedia Arcane series called "Blood Magic Oaths and Sacrifices" I believe it was called. It wasn't a bad from what I remember.