Rockstar has revealed how Grand Theft Auto Online will work with the release of a gameplay trailer and some key details.

It will come as part of Grand Theft Auto V, sharing gameplay features, geography and the nuts and bolts of the game, but will allow up to 16 players to play at once in a persistent online world. In addition, Rockstar will continue to develop the online features after the game launch.

"Grand Theft Online takes the fundamental Grand Theft Auto concepts of freedom, ambient activity and mission-based gameplay and makes them available to multiple players in an incredibly detailed and responsive online world," says Rockstar.

It will work like many MMOs in that players can explore alone, co-operate with each other to complete missions, or band together in groups.

Rockstar will also let players create their own characters for GTA Online, change their stats and appearance and even customise vehicles for use in the game.

The multiplayer game will be available on 1 October. GTA V will be released for Xbox 360 and PS3 on 17 September.