Just like all other magic-users, the various types of Blood Mages use spells from one of the three schools: Holy, Unholy or Elemental. They are subject to the same rules of Focus and backlash as any other mage. They cannot know both Holy and Unholy schools. Their spells do the same things, work the same ways, cost the same amount of MP.
The difference is that Blood Mages use their HP to cast spells, instead of their MP. Each point of HP can be thought of as 2 points of MP for the purpose of spellcasting (so if a spell requires 10 MP to cast, it'll take 5 HP instead). This means that with a little planning, you can have a quite impressive amount of points for spellcasting; it also means that you are hurting yourself by casting spells.
Due to the body's natural self-preservation instincts, you cannot (normally) kill yourself through spellcasting. There are disadvantages which will allow you to override your self-preservation instinct, or a particularly intense situation might inspire you to give your life for the cause, but normally, you cannot cast spells that will drop you below 1 HP. (You can, of course, still be brought to 0 HP by a combination of spellcasting and taking incoming damage.)
In all other ways, they function like a normal priest or mage: they must still apprentice to a master or study at the Magic Users' Institute to learn their spell schools; they must maintain Focus while casting or suffer backlash; they cannot worship both the Gods and the Demons. The only difference is in how they get energy to cast the spells.
Magic is not always the answer for you. You are more cautious and pragmatic, and generally seek non-magical solutions to problems, to avoid hurting yourself unnecessarily. Casting spells doesn't carry with it a sensation of pain, but of growing weakness. And if it's truly necessary, you are glad to do it, of course.
You won't call yourself a "Blood Mage" - this is the term the Magic Users' Institute has concocted to refer to the use of a person's health to cast spells. Blood Mages who specialize primarily in Holy refer to themselves as Theurgists. Unholy Blood Mages (which is a chilling term all on its own) prefer Warlocks. An Elemental Blood Mage would call him/herself a Shaman.
As you've probably figured out, it's worth it to put some extra points into buffing up your HP. You will NOT have MP in addition to HP; the only resource for casting spells is your health. Also keep in mind that your effective "MP" is twice what your HP is ...minus 2. So if you have 20 HP, you have 19 HP you can cast with (because you normally can't cast anything that will reduce you below 1 HP), which translates to 38 MP (not 39). Thus (HP x 2) - 2 = your MP. You can record this on your character sheet under MP if you wish, for easy record-keeping, but remember that it isn't actually MP. Remember also that any damage you take will reduce your MP pool accordingly. If you have 20 HP and take 5 points of damage, you're down to 15 HP, which would mean 28 MP remaining ((HP x 2) - 2).
You may also find yourself casting more defensive spells; sure you're going to be hurt (and lose HP) whether you cast the spell or not, but if the difference is between losing a couple HP casting a shield or losing a lot more HP by taking the hit, the shield's probably the better choice.
Just as with MP, HP is spent at the time the spell GOES OFF, and not before. So if you lose Focus in the middle, you'll have to deal with backlash, but you haven't lost that HP that the spell was going to require.
.:Main Index:.