There is also a very interesting rule about ki skills in the book, if we are talking about the RQ 3 book. If you are going to allow your players to attain ki skills, be careful to follow the rules about advancing them, and don't allow IRs for those (only the natural occuring crits in dangerous situations).
The idea is that someone really masters a skill (needs to have 100 to start), and can then do amazing feats. The thing can be seen in many eastern movies, very often featuring in martial arts, where someone splits rocks with his bare hand, runs up a vertical wall, or vanishes in plain sight. Using the skill did cost 1 personal MP every instance, which sets a clear limit.
Our barbarian fighter (styled after Conan, so no magic use) at least loved the concept - he said it made him feel still powerful in the later game, where spellcasters often dominate (even if he had but two such skills).