Discussion:How could you implement "Black Magic" in a ballanced way?
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 Editing Discussion:How could you implement "Black Magic" in a ballanced way?
I am wondering how I could implement "black Magic" in a ballanced way in D&D. First, I should explain what I meann by the term "Black Magic". I am talking about it in the "Magicians Guild" books- by Trudi Canavan. Black magic basically involves cutting the skin of someone with a knife and drawing magical energy from the wound. This energy can be stored indefinatly for later use. The problems of this include the possibility of a PC simply murdering hundreds of people to steal their power. I was considering the mechanic being that you take a number of HP from the person you are drawing power from, and you can cast 1 level of spells per 5hp taken. I was considering making it a feat, and limiting the amount a spellcaster can store. Any thoughts on how well this would work and how to better ballance it?
The Book of Vile Darkness has some interesting rules on sacrificing people for Xp or magic. Would be a good place to start.
Ah, I don't have it. Darn.
An interesting section of that book concerns the use of souls as power. You can extract a soul using infernal machinery or something and then the soul can be used as a spell component or you can use the soul to make a magic item the soul is worth 10 experience points so the more souls you have the less XP you have to give up to make an item.
I had an idea to do black magic that I (unsuccessfully) tried to implement with Devil Lore spells. The idea is that you "invest" hitpoints into a spell until it is cast. Instead for your black magic you could have the caster lose 1 HP per spell level that cannot be healed until they get 8 hours rest (and if you want to be nice, the hp comes back with 8 hours rest). Don't have spells per day with this variant.
Problem? Mages become "tanks" because HP will be their highest priority. The problem for mages is that they now rely on both a casting stat and Constitution. So... You can merge the idea of paing HP with investing HP. In order to cast spells above 1st level the wizard must have invested half the HP cost beforehand. That means their HP will start out lower (unless they want to stick to 0th and 1st level spells). For example, a 5th level wizard with 35 HP could invest 15 HP so that they can cast 15 second level spells (though that would bring them to 5 HP -- ouch)! It needs tweaking but you get the idea.
Perhaps look into Corrupt spells? Neither arcane nor divine, they're cast and incur some damage to your character for casting it, typically ability damage. Then again the costs tend to be pretty severe (we're talking instant coma if you're too low a level... 3d6 Wisdom damage? Holy crap...) so you may want to craft your own, dumbed down versions. Unfortunately I believe that is also in Vile Darkness. Since you lack it and probably need to custom make this anyway, it wouldn't be too bad starting out from scratch.
I agree that The Book of Vile Darkenn is a good resource if you want to play around with "black magic". It seems that Sam's inital idea would work fine, with maybe a limit of how long the energy can be stored, and making the process of extraction long enough that one can't perform it too many times in one day.
Also, there's just the fact that it would be an evil, horrible act. If a PC tried it too often, then they'd have to deal with serious retalition attempts - a good reason to not go crazy with the ability.
The mechanic as it currently stands is a feat called "Black Magician" (not yet implemented). A character with the feat can use it in two ways- they can take power from a willing ally, or they can take power from an unwilling enemy that is defenseless (could be attacked by a coup de grace). Taking power from a willing ally is not necessarily evil, and involves cutting the ally and drawing a number of hit points (or spells per day) from the character (chosen by the willing participant). Anything taken are removed from the willing participant. Spells per day are simply added to the Black Magician's spells per day, and Hp are divided by 5 and placed in the character's spells per day (each 5 hp are worth 1 spell level (or two 0-level spells).Hp taken in this way are recover by the participant by 8 hours of rest. Taking power from an unwilling participant who is defenseless is an evil act (without good reason for it). It works in the same way, except that the Black Magician decides how much to take, and the unwilling participant is allowed a will save to prevent it.
Spells gained in this way remain until they are cast, and cannot be recoverd by resting.
The problem with the mechanic is that it allows a spellcaster to be too powerful. So it needs limits. I sppose I could limit the amount that can be stored to half of the character's full spells per day, and I could apply charisma or wisdom damage for using it excessively or on an unwilling participant (as suggested by Eiji). Would that be balanced though?
Sounds good to me. Ability damage is a good way to prevent multiple castings (as is XP). While it can be recovered, it requires additional expense and time to do so.
I just recalled some notes, Unearthed Arcana variant rules I believe, about ritual magic and spells. If these black magic spells are of the ritual variety that's also another good place to go. You can ad hoc a while lot of it, from multi-day casting, sacrificial requirements, number of casters, and more. Good for producing what effects you want for plot device spells. Your feat would thus be a pre-requisite to casting Black Magic type ritual spells. -- Eiji 14:11, 15 February 2008 (MST)
How about "A character cannot have than half of his spells per day worth of spells gained from black magic at any one time and takes d4 charisma damage for using this ability on an unwilling participant or more than 3 times per day" as a limit on it? Should I add an xp penalty?
Generally speaking in dnd everything based on "per day" abilities. To help balance black magic I'd suggest that you should not be able to store power for more than one day. An XP penalty for the caster is unnecessary unless the spell they are casting would normally require one. I'd suggest that a progression to an evil alignment and slow charisma damage maybe would be all you'd need. Personally I think role playing the negatives would be better ie: no cha damage just angry mobs of villagers.
I cant help but think of Well of Darkness (book cant think of author), in that book a couple of people use void magic everytime they use the magic they get a boil (of some sort) eventually they get covered in these wounds and then eventually die. Working something like that into mechanics would make for an interesting ability.