Sandbox

From Wikipedia

An open world is a type of video game level design concept where a player can freely roam a virtual world.

The term is sometimes used interchangeably with "sandbox" and "free-roaming"; however, the terms open world and free-roaming describe the game environment itself and allude more to the absence of artificial barriers, in contrast to the invisible walls and loading screens that are common in linear level designs. The term sandbox refers more to the mechanics of a game and how, as in a physical sandbox, the user is entertained by their ability to play creatively, boundless of artificial structural constraints, and with there being "no right way" of playing the game.

Despite their name, many open world games still enforce restrictions at some points in the game environment, either due to absolute game design limitations or temporary in-game limitations (such as locked areas) imposed by a game's linearity.

Microbadge:

VGG: Sandbox genre fan