If you are playing the original PS2 or Xbox versions, there are local multiplayer icons hidden throughout the world that let a second player join as a pedestrian to help CJ cause mayhem, though this doesn't progress the main mission story.
together with synced gameplay and shared driving. SA-MP & MTA: For a more chaotic "community story," San Andreas Multiplayer (SA-MP) Multi Theft Auto (MTA) gta: san andreas uptodown
The "story" of the game itself—and how you can "put together" a playthrough with others—is as follows: The Story of Carl "CJ" Johnson If you are playing the original PS2 or