Pokemon. :P

are you metnak son of kosmak? why would you even ask such thing it makes no sense. but yes like mentioned before, titan quest has something. besides that, in dragon age origins you can become a blood mage. are you happy now?..

The Shadowrun Return games as well, if you cast a spell before the timer has refreshed the caster takes drain - HP damage.

Albion (German rpg from 1995) did that; if a magic user ran out of mana points you could still cast spells, but hit points would be used instead.

Actually, I see the Pokemon situation as different. If you run out of PP for a move, the game won't let you use that move, but can still use others. If you run out of PP for *all* moves, only *then* do you get to use Struggle; you don't use your regular moves. The HP loss from Struggle is not a cost of the move, but rather a side effect, and it isn't the only move that works like that (I believe there's a move called Double-Edge or something like that that has a similar drawback).

Incidentally, Struggle seems to exist solely to ensure that a battle won't last forever. Consider its properties:
* Will never run out of PP, so you never lose the ability to use it
* Causes recoil, so even if the other side keeps healing, the fight will still end
* Starting in 2nd gen, will hit even ghosts, who would otherwise be immune

By the way, it's interesting to note that, in the 1st generation games (Red/Blue/Yellow):
* Enemies have infinite PP. Hence, enemies will never use Struggle.
* Struggle will fail on ghost types. Hence, in a link battle, if both sides are using ghost types with no PP remaining and have no more Pokemon to switch to, the battle is a stalemate; neither player can end the fight except by choosing Run (which forfits the match).

sorry bro i gave all my fucks to Haydee - no fucks left for you :-/

The warlock in WoW has a lifetap spell to which drains your HP to make mana for spells.

I think The Elder Scrolls had something like that, in Morrowind or Oblivion, I need to try out Daggerfall again now that I mention the series.
,

Interestingly, in the Android/iOS game DotQuest, the party mage learns a spell that does just that. Of note is that she also has healing magic, so you effectively have an infinite (though slightly dangerous) loop where you use magic to heal, use HP to restore MP, then use more magic to get the HP back. That spell completely changes the game, as it eliminates the need to conserve MP entirely.

Edit: I just thought of another special case: In Paper Sorcerer, the Vampire gets healing spells that cost the caster some HP (but no energy or cooldown), including a revive spell that is learned rather early. Combine that with HP draining attacks and you have a rather interesting sort of healer.

Return to Krondor isn't, you have separate spellcasting there, normal system.
Not in Morrowind at least. There's it's magicka, rather typical system, though it annoyingly doesn't just regenerate. Enchanted items do though. My healing belt (plain belt with an 1 MP healing spell on use) got me through most things where needed, but mainly through most armor training where I just sat there getting pummeled by weak stuff, remembering to use it a bunch of times in quick succession whenever needed.

Guild wars' necromancer used hit points and Mp. Before one of the first big patches, teams of necromancers would have 2 people kill themselves with magic casting, then two people would raise aundead minion, then Rez the necromancer. They would repeat this process several times before the gate opened so that in a PvP match, your little team if 4 would be rushed by roughly 24 zombies and meet their death promptly.

It was fun while it lasted.

I remember avidly using a spell where I had to injure myself to imitate damage being lost with an enemy attacking me.

Or mirrored damage, you hit mee, you get hit back with the same damage or more, something like that.

huh? :P

I consider that to be different. (Maybe you are thinking of the Reflect Damage spell in Oblivion?)

Interestingly enough, Paladin's Quest have a couple spells that reflect damage in a sense; one for magic damage and one for physical. It turns out that the physical one is the only way I have been able to kill the final boss. (Note that these spells do not reduce the damage you take; an attack that would deal 500 damage still does damage, it's just that the attacker now takes 250.)

Morrowind there may have been a spell that hits the enemy for however much damage they have done to you or something. I can't be sure.