En Masse Entertainment is now offering a free playable trial for the North American edition of TERA, offering the chance to try Bluehole Studios' MMORPG free of charge. The trial is offered on this page along with a playable demo offered through Gaikai that allows you to check out the game's combat instantly. Here's word on the trial:

The TERA trial is good for seven calendar days from the time a player enters the trial code. Players can level up to eight characters to level 23 on one server during the trial. There are some additional restrictions—trial players cannot vote in TERA elections, for instance—but for the most part, players can enjoy the full benefits of the game during their week of free play. All players need to join the world of TERA is an En Masse account. Then they can enter the code “TERATRIAL” to download and play TERA.