Knights of The Old Republic (or KOTOR) is the fist Star Wars RPG game and one of the best RPG's ever! The game was made by BioWare and published by Lucas Arts. Although first it was designed only for XBOX, the game was ported to PC and Mac. It uses the d20 system, from the Wizards of The Coast Star Wars Roleplaying Game Rules.
The story is set 3.956 before "A new Hope" and lets the player to choose between becoming a feared sith lord or a respected Jedi knight. The game starts with you wakening on the Endar Spire, a republic star-ship attacked by the Sith fleet. The game's nemesis Lord Malak (Revan's ex-apprentice) orders the destruction of the republic ship in order to kill Bastilla (the Jedi who defeated Lord Revan). In the last moment you manage to escape with republic war hero Carth Onasi and land on the Sith planet Taris. There your main quest is to find Bastilla and escape the planet before the Sith finds you. After many battles with the Sith forces and thugs you manage to find Bastilla, steal a ship (the Ebon Hawk, the fastest ship in the galaxy) and escape the planet right when Lord Malak orders the destruction of Taris. Your next destination is Dantooine, the planet of a Jedi training academy, where you receive training in the using of the force. After completing your trials you receive a quest from the Jedi council to find the Star Forge (a possible weapon used by Lord Revan and his apprentice Malak). After getting close to finding the Star Forge you discover a very interesting thing about Lord Revan that makes your heart to stop, your ears to bleed and your brain to explode.
The game's graphics are not very impressive for 2003 and the game is bad optimised causing you lag even though you have the recommended requirements. Although the graphics receive a low mark the gameplay receives a solid 10. In 90% of the game you are with your party composed of 3 party members (including you) and you can pause the game at any time to give each party member individual orders. Harder NPC's require more thinking and more pausing because the player needs to react to each attack different. At the beginning of the game you can not use force powers or lightsabers but after your training on Dantooine you become a full user of the "Force" and you can choose (through actions or game dialog lines) on what side you are: dark, light, or neutral. Each force power has its own alignment: dark, light or universal. If you are good then dark side powers cost more and light side one's cost less and vice versa. The universal powers remain the same.
The game let's you choose between a big arsenal of weapons that can be of 4 types: lightsaber, sword, ranged gun, grenades. Also you can between a big arsenal of force powers like stun, lighting storm, droid stun, force push etc. The most important powers that are required in order to finish the game are: heal lv 3, lighting lv 3, force immunity, master speed, dominate mind and drain life at least lv 1 (for Malak).
Knights of the old republic has 6 classes and you can only choose two. At the beggining of the game you can choose between soldier, scout, scoundrel and after finishing your training on Dantoine you can become a jedi guardian, sentinel or consular. Soldiers and Jedi Guardians are based on combat, Scout and Jedi Consular are based on stealth and force powers and Scoundrels and Sentinels are a combination between the previous classes.
In my opinion KOTOR is the best Star Wars RPG and is one of the best video games ever because of it's unique and mind-blowing story and challenging gameplay.