A Barrier is a feature present in every zombie map except for, in very rare cases, some fanfiction maps, like Lockdown. Barriers act as way for the zombies to get into the map. They must first break down the barrier before getting in, allowing the players a chance to kill them before they enter, or at least slow the zombie down. They can be also be repaired, and you get 10 points for each part of the barrier to repair. There are several different types of barriers.

The power-up, Carpenter, repairs all broken or semi-broken barriers, whilst giving all players 200 points if there was at least one fully repaired barrier.

Types

• Standard - These barriers typically have 6 parts to them, almost always being boards. Sometimes, like in Ascension, it might have something different then boards, like metal bars. Prior to Der Riese, all barricades had 5 parts to them. World at War Nacht der Untoten, Verruckt and Shi No Numa still have 5 parts.
• Walls - Sometimes zombies will make a whole in the wall to break through. While these are less noticeable, they also have more pieces for the zombie to break away and the player to rebuild.
• Window - This one's only canon appearance is in "Five". These are the only canon barriers the player can break. While they may be glass, it is repaired with boards, so once all the glass is gone it will basically be a standard barrier again.

Trivia

• In the iPod Touch/iPhone game, World at War: ZOMBIES, the zombies cannot hit you through the barrier.