True to the B/X rules, there are no rules for psionics in the core BFRPG rules. Psionics first appeared IIRC in OD&D Eldtrich Wizardry. No matter how many times I reread the rules there, I am not exactly certain how to even play an NPC psionic.
In the spirit of D20 with an old school feel, I plan to add a psionic-type of class called a Mentalist. In some ways, the Mentalist will be similar to the Psion class from d20. A character is a mentalist or he/she is not, no automatic dual-classing. (Regular BFRPG dual-classing rules apply.) The mentalist will not have power points to track (and will certainly not have a mental armor class and mental hit points.YIKES!) In many ways, the class will be written as a third type of spell caster. At various levels, a Mentalist character may use a certain number of powers. Unlike spellcasters, though, they can repeat the same power multiple times as long of slots are available.
One interesting power is the ability to psionically alter a weapon to be a silver weapon. This ability makes them a natural opponent of lycanthropes and any other creatures with an allergy to silver.
A mentalist can only use daggers, short swords, and crossbows.
One unique aspect of a mentalist is how they combat other mentalists. Basically, every mentalists can learn up to five attack forms and five defense forms. Each form can overcome two others, nullifies one form, and is overcome by two forms. The easiest way to resolve mentalist combat is to use nacho, ninja, pirate, robot, monkey. It's like rock, paper, scissors but with five choices instead of three. Still, dice options are available.
The Mentalist class will appear soon on dragonsfoot.
Sorry for the change in posts. Didn't have time for the review to be written before publishing.