An overworld or a hub world is, in a broad sense, commonly an area within a video game that interconnects all its levels or locations. They are mostly common in role-playing games, though this does not exclude other video game genres, such as some platformers and strategy games.
An overworld or hub world is an area within a video game which connects its other levels or locations. The term can also refer to a safer area which players frequently return to, like a town. They are common in adventure games, role-playing games (RPGs), platformers, and dungeon crawlers. Multiplayer games have hub worlds which serve as a centre for interaction with other players and non-player characters (NPCs).
Hub worlds in single-player games are often used for worldbuilding, while hubs in multiplayer games are more purposed for storage for weapons and equipment, as well as restocking supplies. They serve as safe areas in between dangerous areas and quests where players can take on more passive actions. Wired and Kotaku described overworlds as a sort of "home" for the player in-game. They have also been considered an essential element of RPGs.
The arcade game 005 (1981) was one of the earliest examples of a hub world. An early stealth game, players could enter buildings like ice rinks and warehouses from the main screen to avoid enemies, leading to different screens. The final scene tasks you with controlling your getaway helicopter to escape and finish the level. Dubbed "a game in four screens", 005's main screen was then not considered a hub world, but was described as a "RasterScan Convert-a-Game" in The Encyclopedia of Arcade Games (2004).
In Super Mario 64 (1996), Princess Peach's Castle serves as its hub world. Free of enemies, the castle serves as a safe area where players can experiment with its movement system and serves as an entrance to all other levels. Players are free to leave the castle whenever they wish.
In terms of video game music, overworld themes are often orchestral in nature, and of greater length and complexity than other pieces in the same game, due to the amount of time spent travelling the overworld map. Because players will usually visit a single level or area a few times in a given play session, the music for any such section of the game will typically be shorter and/or less complex, and thus less time-consuming for the designers to produce. The overworld theme frequently functions as a main theme of a game, often used as a motif for other tracks (e.g., a "romance" theme features the main melody of overworld theme, orchestrated in a different key).