Noclip Mode - Description

Description

The term was popularized by the games of id Software in the 1990s. The name is derived from the command traditionally used to activate it: typing "idclip" in the game's command PC game console for Doom II (the previous one was "idspispopd"). The cheat is commonplace, particularly in action-oriented first-person shooters such as Quake or Half-Life. John Carmack of id Software has told fans that he derived the term from the concept of "clipping a movement vector". The first instance of the "No-Clip" code probably came from id Software's popular game series, Commander Keen.

Noclip modes (and other similar modes) often originate as a means by which developers test games. If a new feature is implemented in a game but requires play to determine whether it works, it saves time if a developer can quickly reach the relevant portion of the game by avoiding death or by "flying" over time-consuming regions of the game environment. This source of God modes often manifests itself in the route by which players activate these modes - for example, running a game with a development mode flag.

The equivalent code for a given game may also turn off clipping, but this is not the reason why the player can walk through walls. The code turns off collision detection, an entirely separate toggle. The code generally does not turn off back-face culling, which is why the other side of a one-sided wall is not drawn when you use "no collision" mode to walk through it. It is unclear why id Software chose to call a "no-collide" code a "no-clip" code, unless the code also turned off clipping, and that was the (developer-intended) point to the cheat: to test the system when everything in the level was being drawn at once, and also remove collision so that one could quickly inspect the level for problems.

Some developers have continued in the fashion of id Software, and refer to this cheat as "clipping" even when it only turns off collision detection, perhaps due to user familiarity with id's code. Other developers call the toggle by its proper name.

Generally speaking, walls and objects have no "substance" unless advanced in-game physics is being used. Collision detection refers to the intersection of a wall or object with the player's avatar. If there is an intersection (collision is on), the game stops the player's motion, as if they had bumped into the intersecting object. Otherwise, the avatar will not interact with the object and will pass through it. This is a relatively simple method of implementing in-game physics with walls.

No-clipping can conflict with other elements of the game. For instance, in Duke Nukem 3D, and the aforementioned Commander Keen Series, having no-clip and walking outside the level area causes death—and if the player has god mode activated the game will be left in an infinite loop or crash due to the way god mode was implemented. In most source ports for Duke Nukem 3D, this problem is corrected and it instead behaves more like Doom.

In the multi-purpose video game Garry's Mod, no-clipping can be used to fly about and increase the versatility of your construction. This is one of the few games where no-clip is not considered a cheat, and the function is bound to a key by default.