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In computer and video games, linearity denotes that the objectives of the game must be completed in a fixed sequence, sometimes revealing elements of the plot, in order. Non-linearity means that the player has a selection of options. Gameplay typically combines both linear and non-linear moments, but whole games may be characterized as being mostly linear or non-linear.

Non-linear games have the potential advantage of providing a greater sensation of freedom, as well as offering better replay value. On the other hand, linearity helps developers to provide good narrative, and the gameplay may be more finely tuned since the developers have had the possibility to anticipate all possible situations.

Most 2D platform games are largely linear, featuring one-directional levels which the player must run through from one end to the other. Super Mario Bros. (1985) is a good example since the game does not even allow going backwards within a single level, and while there are warp zones they only give the option of skipping levels, with no alternative paths. Super Mario 64 (1996) famously introduced three-dimensional worlds in which the player chooses which direction to explore. In contrast, Super Mario World 2: Yoshi's Island is generally regarded as the most linear game in the series, since there are no warps and the player must complete all 48 levels in the order given.

Non-linearity is mostly applicable to games which allow for exploration: adventure- and action-adventure games, role-playing games as well as more recent platform games and first-person shooters.

Games which are partially non-linear can be subjected to speedrunning or sequence breaking. Examples of games in this category are Super Metroid, Metroid Prime, and the later Castlevania titles.

In most games the elements of the plot are essentially fixed. They may reveal themselves as cutscenes; if so, these cutscenes can rarely be accessed out of order.

In some games different threads of story are woven together in different orders depending on a player's actions. This can help obscure the fact that each thread is essentially unchanging.

Some games claim to have non-linear stories but this is usually only at negligible levels of detail. The arc of the story usually remains intact.

Linearity also applies to level and world design. In a game with linear levels, there is only one route that the player must take through the level ie. to get from point A to point B, a player must pass point C. This can make players feel bounded in a way which reduces immersion, particularly if players are forced to rely on the linearity of a level to "feel out" their way through the game. In games with non-linear levels, players might have to revisit locations (eg. A to C to D to C to B) or have the option of various routes through a level (eg A to D to B or A to C to B). They are sometimes given an overall objective, rather than being given a sequence of tasks to the same effect.

For example, the first game in the Splinter Cell series was criticised for being too linear. This was amplified by the way in which the central character, an National Security Agency super-spy, would be expected to use unexpected paths to complete a mission in order to evade capture. There are more viable routes in the sequels, suggesting that the developers consciously tried to address this criticism.

Project IGI, on the other hand, had notably non-linear levels. You were given an objective within each level (usually a small mountain military base), but the route through each level was deliberately left open. There were very few obstacles preventing players from taking whichever route they found to be successful.

• Sandbox (videogames)