Sandbox

Sandbox is a type of game design that consist mainly in an open world environment and non-linear gameplay. Although there is a large variety of sandbox games, the Grand Theft Auto series is considered as one most prominent examples of this type of gameplay.

Game Design
From a design perspective this approach to game design the sandbox has two main traits: There is a third trait in some games, that being a procedurally generated world, which means that each time that a new game is started a new map is made using algorithms. This is not the case in the GTA series.
 * Non-linear gameplay: the player can choose how they like to play the game, such as the order in which missions are played, as long as it doesn't change the storyline.
 * Free-roam: The user can explore the game world as they like. Again, this is often manipulated to avoid discrepancies in the storyline (Like in GTA: San Andreas, where the cities are unlocked as the player advances in the game's story)

In The Grand Theft Auto Series
All GTA games are of a sandbox type. Grand Theft Auto III is considered as the most important sandbox game in video game history, as it was one of the first best-selling games to be of such a nature. This inspired other developers to make games of this kind like Fallout and ''The Elder Scrolls. Although one of the most influential, the GTA games were not the first, nor the last, sandbox games, the series directly inspired a wave of games deemed as "Grand Theft Auto clones" like Saints Row and Driver.''