There's a new Star Wars film out at the moment, and you can be sure EA and Bioware will try to get some of that enthusiasm over to Star Wars: The Old Republic. Players can now try the latest expansion, Knights of the Eternal Throne, for free until the January 3. To gain access to the expansion, you need a "preferred" player status, attributed to players that paid a subscription before the game went to a free-to-play format, or to players that have bought Cartel Coins with real money.
If you decide to become a Premium Player (that will also get you full access to the expansion) before January 3, you will also be getting 500 Cartel Coins for micro-transactions. You can read all the details on the free trial right here. Will you be getting into the expansion now it's free?
