Well, quick explanation: There is block, attack, and power attack.
Block: Stops attack, is broken by power attack
Attack: Well, it is basic attack. Stops power attack, is stopped by block
Power attack: breaks block, is stopped by attack.
This is (over)simplistic version of fighting game like Dead or alive or Tekken. It fits for JE nicely, since it is asian world and fights are mostly martial arts. For that kind of game (and to its world) this is perfect. Oh, it is little bit spiced up by all kinds of different fighting styles.
However, we all know how Kotor series have been. And such simple system would really ruin fights. No flurry, fighting feats etc.
Heck, in JE there even isn't D20 system. And Kotors are D&D games... <_<