Grand Theft Auto: San Andreas
Weed is referenced in earlier games, most notably Grand Theft Auto: Vice City, where it is mentioned by Dwaine, Jethro, and Couzin Ed. It makes its first appearance in Grand Theft Auto: San Andreas. It is seen during the mission Are You Going to San Fierro?, in which CJ must burn weed fields belonging to The Truth before authorities arrive, at the farm in Leafy Hollow. While the marijuana plants are burning, Carl is visibly affected by the resulting smoke, as the camera will start to sway and Carl will comment on how he is starting to get dizzy.
Ryder smokes weed laced with PCP, a mixture which he makes himself and calls "water". All gangs are seen smoking marijuana. Also, some pedestrians in Los Santos can be heard saying things such as "that ese put dust in my weed" and "where the weed at?".
Grand Theft Auto IV and Episodes From Liberty City
During Grand Theft Auto IV, Little Jacob is almost always seen smoking weed during much of the storyline. His best friend and business partner Real Badman also frequently smokes weed. Most of Jacob's missions and jobs for Niko also involve weed.
Grand Theft Auto: Chinatown Wars
Grand Theft Auto V
Weed makes its first official interactive appearance in Grand Theft Auto V. It can be smoked using a bong by both Michael and Franklin. Michael and Franklin will get high and react to the effect. The Ballas have a marijuana growing/packing business set up in an abandoned sawmill just south of Paleto Bay. Smoke on the Water, a medical marijuana pharmacy, can be purchased by Franklin although he won't able to buy anything from the store. Marijuana plants can also be seen growing at Braddock Farm. The Grass Roots series of stranger missions center around weed; Barry, a man wishing to legalize the drug, meets Michael, Franklin and Trevor on separate occasions and wants them to sign his petition. He offers each of them weed, which Michael and Trevor reluctantly take and experience frightening trips as a result of the weed being laced with a hallucinogen. Franklin, however, doesn't experience the effects and chastises Barry for its low quality. Barry later has Franklin deliver two large shipments of weed to his apartment for use in a "smoke-in" protest at city hall. As it turns out however, Barry was lying about the protest and uses the weed for himself.
If the player is Trevor, they can go to a weed farm near Grapeseed. They can rob it for approximately $10,000-$100,000. That is also the only place a Confederate flag can be found.
In Grand Theft Auto Online, weed functions the same way it does in GTA V. It can be smoked by using a bong if the player owns an apartment, or when visiting another player's apartment. The player will experience a blurry effect, green tint and sound being cut out to simulate the feeling of being high. If consumed in a massive concentration the player will eventually pass out and re-awaken at the Central Los Santos Medical Center, even if the player is not located in Los Santos. It is possible this hospital is supposed to serve as a drug-rehabilitation center as well.