So, I had this idea entirely out of the blue for a game where you're all necromancers.
Hey, get back here!
As those familiar with my disposition will guess, this would not be a deeply serious game exploring the darkness and depravity that lurks within the human soul, or experiencing what it might mean to speak with the dead, or how being a shunned and hated practictioner of sinister arts might turn society against you and how you might react. It'd just be a fairly standard heroic fantasy game. Where you're all necromancers. In fact, I'm quite tempted to say it should be an exaggeratedly cheerful game (something a bit twee) where the people who get called on to solve problems are the "friendly" neighbourhood necromancers. The fact that you solve them with dominated skeletons, horrific apparitions and eldritch bolts of necrotic energy is just by the way. Necromancers ain't necessarily bad people. Cat stuck up a tree? Summon a flock of crows to fetch it. Or blight the tree so it decays and brings the cat crashing down. Or evoke a sense of blasphemous dread that brings it yowling down in terror. Or engulf it with your steely will and force it to slink down to bow before you. Then Mrs Goggins will give you some cake and a cup of tea for being so kind.
So, what system would let you run a game like this?
Given the specialised focus, what you want is to be able to articulate clearly how your necromancer is different from the next one. This might come down to different spell selections, different approaches to problems, or different characters. A pale, gothic necromancer in black lace is different from a cackling, withered necromancer in tattered robes.
I really don't think something like D&D would work for it, because the class framework pushes you towards certain roles. A necromancer would struggle to have hit points, and I don't think there are enough thematic options to make you anything other than a wizard without delving heavily into splatbooks. The combat focus of the game would cause problems for fragile casters with poor combat skills and a limited spell pool. Also, I don't think the health model really fits my concept here, somehow.
Something vaguely BRP-like might work, if you just came up with appropriate skill lists. A set of necromantic talents where everyone assigned points, and use those (rather than spell lists) to determine your effectiveness.
Weirdly, I'm somehow tempted to try it with FATE despite my rather meh experience with FAE. A system where (it seems) you assume you can do stuff and highlight a few key distinguishing features seems like it might well fit.
And of course I could put my money where my opinion is and hack together a Numenera adaptation, but I suspect it would involve quite a lot of hacking since I'd basically be devising new Nouns, Adjectives and Verbs.
So just a very quick post there to get the idea down while I still remember it. Comments and recommendations very welcome, I'm not particularly system-aware.