It's not necessary to have all possible psi-effects matched by technology; it just doesn't introduce balance issues if it does. Once you have capabilities unique to psionics then you have to start applying the munchkin test. Think of the most annoying, entitled powergamer you've ever played with and try to imagine what he might do with a character that had that power.
As a reformed munchkin, I get that. But I’m also not a fan of über balance in games, especially RPGs. So while I’m not going to nerf psi in the name of balance, neither will it be given free reign.
Like I said, I need to figure out HOW I want to limit the psionic disciplines.
The first idea was the metabolic energy costs. They’re going to be large. That means that psionic PCs will be hearty eaters, as mentioned. This will translate into limited utility- most psions won’t be able to rely on their powers alone.
This will also mean that those in certain professions may well be consuming pharmaceutically enhanced foods, have cybernetic enhancements or even be hooked into machinery to supply them with the energy they need. Biological Navigators, for instance, will not only be feeding data into their ship’s computer system while on duty, but also into a ship-mounted rapid energy infusion system.
Some limitations I think make senunder consideration:
1) psionic activity can be detected by special sensors, so it’s not 100% undetectable
2) certain psionic effects may take time and concentration to use. Some may also be disrupted by physical contact.
3) Ranges on powers will vary by type. Something like TK or telepathy might have long ranges, but powers that change the way a body functions might be limited to one’s self or touch.
4) certain materials may block psionic energy or inhibit a psion’s biochemistry so as to inhibit the use of their powers
5) situational limitations: a TK assassin would need to know something of their target’s biology in order to affect them. A TK engineer couldn’t repair system he can’t perceive. A telepath might not fully understand the thoughts of an alien race.
Other ideas for limitations are welcome!