This may be uninteresting to a lot of you.
On the way to work today, I had a thought. I used to play a lot of roleplaying games with friends, or rather, I used to be the DM (the storyteller for the interactive storytelling that is RPGs). One of the systems, DnD, had 3 different primary types of supernatural powers (originally 2 -- the third was added in an afterthought and a lot of people didn't use them) that, if one made one's career one of the three, one could use. Wizards had use of magic, Clerics/Priests had use of prayers, and Psionicists had use of Psionics (mental powers). The rationale for the origin of each of these powers was decent -- magic exploited irregularities in the nature of things and tapped into latent power in the universe to create effects, prayers petitioned gods (or nature or whatever) to grant a bit of power to create effects, and psionics used mental abilities to manipulate local things (and one's body). The system wasn't particularly well thought out, but it didn't need to be -- one can easily imagine different arrangements. Druids, for example, used prayer magic with their power normally coming from the abstract concept of nature. One could easily imagine giving a more druidic spin to psionics, tying the mental powers to accepting one's role as part of nature, tweaking the powers, etc. As the system did work though, the differences between each system wasn't wide enough, and the systems mirrored each other too much. For example, Clerics and Mages (Wizards), the two oldest classes of the three powers-using ones, too often ended up having very similar abilities -- whereas a Mage might study his spells in the morning, a Cleric would spend time meditating in the morning to refresh their powers. Their process of casting spells was virtually identical, and a number of the powers themselves were duplicated between the two. Psionicists were a bit different, in that their abilities were power-pool based (they didn't need to choose what powers they'd use when they woke up for the day), and they had a chance to fail using any of their abilities. Still, they still had roughly similar sets of abilities that didn't have much in the way of systematic or principled differences from mages or clerics. Teleport? Got that. Disintegrate? Yup. Wound healing? Sure. That's disappointing. The other classes in DnD, Fighters, Thieves, Monks, Rangers, etc. all had bigger differences (especially when one gets into third edition of ADnD). Admittedly the biggest part of a good campaign is the storytelling, not the combat stats and only sometimes the abilities, but I think they still do factor in. I think it would make a lot of sense to come up with solid differences between the abilities of the 3 mystic classes and redo them based around those differences. I present the basics of such a system below:
- Mages - Arcane Magic is based around manipulating raw forces and the nature of things, drawing on sources of magical power from elemental planes. It is a rough tool, bludgeoning reality to its will. It is not well-suited towards more refined effects, and is most suited towards powers that take place while being cast and are done afterwards. Spells that persist afterwards are at most simple autonoma, and have a good chance to go awry after any significant time. As a first step, I suggest chopping divination and illusion magic.
- Clerics - Clerical magic is based on drawing attention and/or power from agents of abstract forces or deities towards ends aligned with common needs or philosophy with those entities. It tends to produce refined effects that are limited strictly to the spheres of power of those forces, with very little truly general-purpose role. I suggest getting rid of most general-purpose powers, making each devotion a subclass with very different abilities.
- Psionics - Psionics are based on treating the body and universe as more controllable and less distinct than they are. Psionic powers are tied to forces and abilities linked to human and animal bodies and minds themselves. As a first step, I suggest chopping out disintegration and other powers that produce gross non-body physical effects.
- Monks (they're not mystic classes, but in some systems they have some spells) - monk powers should be based on manipulating fighting spirit in the body to deliver different kinds of elemental forces with one's blows as part of one's aura.