You cannot play Multiplayer? That's probably because you have just installed the game. Follow 3 easy steps, and enjoy the multiplayer experience freely:
1) Install patch 1.01. You'll need it to join most of the servers. You can find download link, and installing instructions here.
2) We hardly recommend, to install also the most popular mod for Jedi Academy-Jedi Academy Plus (JA+). It isn't necessary to play, but it allows you to access all most commonly used features in multiplayer. You can download it here.
3) Last step is joining server. Jedi Academy is an old game, and sometimes the MasterServer (the server which allows you to see server list) isn't working. If your internet connection works, but you don't see server list, try the alternate ways: