Wolfenstein: Enemy Territory is an online multiplayer game, where the players interact with each other over a network in two teams (axis and allies) to defend or destroy mission objectives. The game is playable over the Internet or a Local Area Network. Like many online games, cheating and exploit communities exist. To counter this, the game has support for PunkBuster, an anti-cheat solution.

The character classes in Enemy Territory are:

There are two sides; Allies and Axis. There are six officially released maps (North Africa Campaign: Goldrush, Oasis, and Battery; Europe Campaign: Railgun, Radar and Fuel Dump), as well as hundreds of custom maps made by the internet community . On each map, the offense needs to complete a certain set of objectives within a limited amount of time. The defense needs to keep the offense from completing objectives until time runs out. Some objectives may be optional, and some objectives can be carried out by either team. These minor objectives assist the team completing them. Depending on Game Mode the action will continue on another map (Campaign Mode) or the same map (Objective Mode, Stopwatch Mode, Last Man Standing).

In all but the LMS mode, dead players respawn all at the same time, every X seconds. In the default maps - assuming that the server settings aren't changing it - Allies spawn every 20 seconds and the Axis every 30 seconds, the only exception being Railgun where both have a 20 second spawn. With default settings, you can see the spawntimer in the right side of the screen. Experienced players should watch the timer all the time - dying to a 1 second spawn practically means losing your position (and a life, if the server has the rarely used Limited Lives feature enabled) and reseting your health and ammo, while a 30 second spawn can be deadly if there are only a few players. A good tactic is to find out the spawn time of your enemy, for example looking at the mission timer, and time your attacks so that every dead opponent will have to wait a full time spawn.

In the official six-map campaign (most common on public servers), Allies are offense for all but one map. In Stopwatch Mode (most common for locked or LAN servers) two teams - most common setups: 6vs6 or 3vs3 - will play the same map twice, once in each side and the winner is determined of who have the fastest offence (it can be a tie when both teams defence manage to keep the offence from completing the objectives until time runs out).

Players may earn experience points in several skill categories. All character classes may earn points in Battle Sense and Light Weapons. Class skills are generally restricted to the current class, the exception being Heavy Weapons (the Soldier class skill).

Players have certain abilities based on their character class. The player has a Power Bar that provides 'power' for their special abilities. The power bar regenerates slowly. Players have up to eight weapon slots, depending on character class.