Barricades

Barricades are used to stop zombies from entering rooms and some maps.

Players cannot walk through them when they are broken, however, zombies can. In, and , the player can upgrade the barricades, however this wasn't included in. In all of the games, PC-wise, barricades can be fixed by pressing the F key, and awards the player XP for doing so. Keep in mind that there is a cap on how much XP you can earn from fixing barricades.
 * 10-20 XP for light damage
 * 30-40 XP for moderate damage
 * 50 XP heavy damage
 * 60 XP for extremely heavy damage or being completely destroyed

In SAS, SAS 2, and Insane Asylum, the maximum upgrade is the Razor Wire barricade, which damages zombies while they attack it.

In SAS 2 and Insane Asylum, the worms from dead butchers can pass through barricades. Be careful when shooting butchers while they attack the barricades.

In, doors that are similar to Barricades are featured in the mission Ice Station. Like the Barricades, the player simply has to stand near them and they will automatically be repaired.

Barricades also appear in the mission Onslaught, where they are not repairable but have much more health. Frames of their sprite suggest that they were originally designed to be opened.

Trivia

 * The barricades were moved to another NK game, Knight Elite