Nonlinear gameplay

File:Assassins creed stealth.jpg

Assassin's Creed is a video game that allows 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. The genre may have begun in the 8-bit-era with games like Elite, Mercenary and Cholo. More recent examples would be the The Elder Scrolls series, Ratchet and Clank (series), Grand Theft Auto series, Jumpgate: The Reconstruction Initiative, inFamous, Far Cry 2, S.T.A.L.K.E.R.: Shadow of Chernobyl, Assassin's Creed, Midnight Club: Los Angeles, Saints Row 2, Fallout 3 and Need for Speed Undercover.

A game that is noticeably nonlinear is described as open-ended or as a sandbox. Nonlinear games are sometimes described as providing emergent gameplay.

Classification

Branching storylines

Games that employ linear stories are those where the player cannot change the story line or ending of the story. Most games use linear stories, thus making the stories similar to those of other fiction. However, even in games with a linear story, players interact with the game world by performing many actions along the way. Many games have offered premature endings should the player fail to meet a challenge, but these are usually interruptions in the player's overall experience rather than actual endings. More recently, many games have offered multiple endings to increase the impact of dramatic moral choices throughout the game, although early examples of nonlinear gameplay exist, such as Chrono Trigger or Fallout.

Still, some games have gone beyond small choices or special endings, offering a branching storyline that players may control at critical points in the game. Sometimes the player is given a choice of which branch of the plot to follow, while sometimes the path will be based on the player's success or failure at a specific challenge. For example, Bethesda Softworks' The Elder Scrolls IV: Oblivion features numerous quests where player actions dictate the outcome of the story behind the objectives. Players can eliminate in-game characters permanently from the virtual world should they choose to do so, and by doing so may actually alter the amount of quests available or the type of quests that become available to them as the game progresses. The effects of such decisions may not be immediate. Branches of the story may merge or split at different points in the game, but seldom allow backtracking. Some games even allow for different starting points, and one way this is done is through a character selection screen..

Despite experimenting with several nonlinear storytelling mechanisms in the 1990s, the game industry has largely returned to the practice of linear storytelling. Linear stories cost less time and money to develop, since there is only one fixed sequence of events and no major decisions to keep track of. For example, several games from the Wing Commander series offered a branching storyline, but eventually they were abandoned as too expensive. Nonlinear stories increase the chances for bugs or absurdities if they are not tested properly, although they do provide greater player freedom. Some players have also responded negatively to branching stories because it is hard and tedious for them to experience the "full value" of all the game's content. As a compromise between linear and branching stories, there are also games where stories split into branches and then fold back into a single storyline. In these stories, the plot will branch, but then converge upon some inevitable event. This is typically used in many graphic adventure games.

A truly nonlinear story would be written entirely by the actions of the player, and thus remains a difficult design challenge. As such, there is often no story in truly nonlinear games. Facade, a video game often categorized as an interactive drama, features many branching paths that are dictated by the user's text input based on the current situation, but there is still a set amount of outcomes as a result of the inherent limitations of programming, and as such, is non-linear, but not entirely so.

Nonlinear level design

A game level or world can be linear or nonlinear. 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 can give the freedom to explore or backtrack, there can be a fixed sequence of challenges that a player must solve 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 to win. The ability to skip, repeat, or choose between levels makes this type of game less linear. Super Mario Bros. is an early example of this, where the player had access to warp zones that skipped many levels of the game. Left 4 Dead 2 is a more advanced example of non-linear level design, featuring an A.I. structure that is capable of generating new level layouts on-the-fly according to each player's individual conditions. This makes it so that players are constantly experiencing a dynamic map layout, and as such may never follow the same exact path twice.

When a level is sufficiently large and open-ended, it may be described as an open world, or sandbox. Open world game designs have existed in some form since the 1980s, such as the above-mentioned Elite.

Sandbox mode

In a game with a sandbox mode, a player may turn off or ignore game objectives, or have unlimited access to items. 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 SimCity.

See also

• Massively multiplayer online games
• Grand Theft Auto clone
• Emergent gameplay
• Open world gameplay