Nonlinear gameplay

A game with nonlinear gameplay presents players with challenges that can be completed in a number of different sequences. Whereas a more linear game will confront a player with a fixed sequence of challenges, a less linear game will allow greater player freedom. For example, a nonlinear game may permit multiple sequences to finish the game, a choice between paths to victory, or optional side-quests and subplots. Some games feature both linear and nonlinear elements, and some games offer a sandbox mode that allows players to explore the game environment independently from the game's main objectives.

A game that is noticeably nonlinear will sometimes be described as open-ended or as a sandbox.^[1][2][3][4] Nonlinear games are sometimes described as providing emergent gameplay.^[4]

1 Description 1.1 Story and plot 1.2 Level design 1.3 Sandbox mode 2 References

A more linear game will feature a fixed plot in a single sequence. Most games feature a linear storyline.

In a truly nonlinear game, there often is no story.^[5] A truly nonlinear story will be written entirely by the actions of the player, and is thus a difficult design challenge.^[5] As such, nonlinear stories usually preserve the overall story arc while allowing multiple solutions to a specific challenge, or a choice between multiple challenges.

Left 4 Dead (2008) features a dynamic system for game dramatics, pacing, and difficulty called the Director. The way the Director works is called "Procedural narrative": instead of having a difficulty level which just ramps up to a constant level, the A.I. analyzes how the players fared in the game so far, and tries to add subsequent events that would give them a sense of narrative.^[6] Practically, however, this has no influence on the narrative beyond the frequency at which stronger enemies are spawned.

A game level or world can be linear or nonlinear as well. In a game with linear levels, there is only one route that the player must take through the level. In games with nonlinear levels, players might have to revisit locations or choose from multiple paths to finish the level.

As with other game elements, linear level design is not absolute. While a nonlinear level may offer players the freedom to explore or backtrack, there still may be a fixed sequence of challenges that a player must solve in order to complete the level. Even if a player must confront the challenges in a fixed sequence, they may be given the freedom to seek and identify these challenges without having them presented one after the other.

A more linear game requires a player to finish levels in a fixed sequence in order to win. The ability to skip, repeat, or choose between levels makes game less linear. The 1995 game Rise of the Triad is believed to have shown one of the earliest (and simpler) examples of non-linear gameplay, where one of the levels in its add-on pack had two exits, one of which allowed the player to skip ahead three levels. ^[7]

When a level is sufficiently large and open-ended, it may be described as an open world,^[8] or sandbox.^[9][10] Though Grand Theft Auto III popularized the open world design in 2001 with its 3D environment, earlier games such as Metroid (1986) had already utilized this form of level design in 2D.

In a game with a sandbox mode, a player may turn off or ignore game objectives.^[11] This can open up possibilities that were not intended by the game designer. A sandbox mode is an option in otherwise goal-oriented games, and should be distinguished from open-ended games with no objectives such as Sim City.^[11]

A sandbox-like structure of gameplay is featured prominently in the Grand Theft Auto franchise.^[11] Other games where players may ignore the game objectives and explore the world as a sandbox include Freelancer ^[12], Crackdown^[10] the Elder Scrolls series, Prototype, Hulk: Ultimate Destruction, recent Spider-Man games, inFamous, and the Pokemon video games.