Wolfenstein: Enemy Territory (also referred to as simply Enemy Territory, ET or WET) is a free multiplayer first-person shooter video game set during World War II. Wolfenstein: Enemy Territory is an online multi-player game, where the players interact with each other over a network in two teams (Allies and Axis) to defend or destroy mission objectives. Players can choose from 5 different classes, all with unique skills and weapons. Through gameplay, experience can be gained. Once a player has accrued enough experience points in a particular skill, the skill is automatically advanced to the next level, providing the player with a new ability or advantage.