Carjacking is a basic act available in all Grand Theft Auto games, where the player possesses the ability to steal an occupied or unoccupied vehicle. It is a fundamental feature in the games, and an inspiration for the "Grand Theft Auto" name, which is a legal term for carjacking.
Carjacking is committed with a simple stroke of a key or button when the player character is close to a targeted vehicle. If the player character isn't already next to a front door of the vehicle (passenger's or driver's side), the player character will automatically walk or run towards the aforementioned door.
Stealing an unoccupied vehicle
If a vehicle is unoccupied, the player may simply break in, start the engine and drive/ride/fly away. For Grand Theft Auto IV, the player must often times take the time to shatter a window of a road vehicle if it is locked (larger vehicles, except for helicopters, however, are unlocked to begin with) and hotwire the vehicle before they can start the engine. If the player interrupts the carjacking by pressing any other button or key in Grand Theft Auto: San Andreas or GTA IV, the player character will simply open the vehicle's door but will not enter the vehicle. Entering a convertible will result in the character simply jumping in without interacting with any doors. Exiting, however, the character will open the door and get out, possibly inferring that the character unlocked the door from the inside.
In certain cases, road vehicles will automatically trigger an alarm when intruded, attracting police attention. This can be averted by tripping off the alarm by hitting it with a weapon or another vehicle, waiting until the alarm stops, and then breaking into it.
In Grand Theft Auto 1, certain vehicles may also be armed with a bomb activated when it has been broken into, serving as a deterrence to carjacking attractive vehicles parked in the game.
Stealing an occupied vehicle
If a vehicle is occupied by a driver, the player must pull the driver in question out before they can enter and drive away. If the player enters via the passenger's side, the player character simply forces the driver out from inside the car; if the passenger side is also occupied, the player character will pull the passenger out before entering (In GTA San Andreas, the player character will even bang the passenger's head to the dashboard before pulling him/her out). If the player interrupts the carjacking by pressing any other key in GTA San Andreas or GTA IV, the player character will simply pull out the first occupant but will not enter the vehicle.
Whereas most games simply depict the player character pulling its occupants out, player characters in GTA San Andreas, Grand Theft Auto: Liberty City Stories, Grand Theft Auto: Vice City Stories , GTA IV and GTA V employ violence to obtain a vehicle. In these games, punches and kicks (common in lower vehicles such sports car) may be used against an occupant, and if the player character in GTA IV is wielding a firearm, he may threaten the occupant at gunpoint and in GTA IV, Niko may slam the head of the driver into the steering wheel if they appear hostile towards him. It is also possible in that game to steal a vehicle without having to "carjack" them. If one aims a gun at the driver of a vehicle (or passenger), they will sometimes say something, and then get out and run away, or, they will back up and drive away, trying to avoid the player. NPC's when carjacked may also end up calling the police for help.
For ships, the player may simply jump aboard the boat, triggering its driver to leave the controls and flee. Carjacking an occupied aircraft may be done in multiplayer modes, but is otherwise difficult in single player mode, if not impossible, as occupied aircraft are often not within reach to the player.
There is a glitch where if the player has a already saved police vehicle, and an officer arrests a criminal, he will get into your car with the criminal in the back and you can carjack your car back and you will not recieve a wanted level (it is unclear whether this is a glitch or not, it can also be done if you aim a weapon at the officer and not get a wanted level). It is possible that the police vehicle that you had saved before is claimed as yours and the officer can be pulled out as if a thug had stole your car. Using cheats and spawning a FIB Buffalo in GTA IV, the police will also get in, but unlike most vehicles spawned with cheats, it will not disappear when another vehicle cheat is used. This is most likely the game identifying it as a police vehicle from traffic rather than one from cheating.
In Grand Theft Auto: San Andreas, if the player enter passenger door while holding the sprint key will push the driver out and kill them instantly for unknown reason.
Interrupting a carjacking
It is possible to interrupt a carjacking in Grand Theft Auto: San Andreas and Grand Theft Auto IV (including its episodes) in full. This can be done on console games, for example, by flicking the analog stick before the character gets into the car. This is useful if you've carjacked the wrong car. However, if the player waits too long before getting in, there's a chance the driver may reenter the car or start attacking the player.
Repercussions of carjacking
Carjacking is not without its dangers. From Grand Theft Auto III onwards, certain drivers will react aggressively towards the player if their vehicle is stolen, dragging the player out, and either reenter their vehicle to drive away, or pick a fight with the player; taxi drivers and gang members are usually depicted with such behaviors.
As expected, carjacking, as is the possession of a vehicle with a triggered alarm, will attract police attention if a police officer is within the line of sight of the crime, often resulting in the player attaining a one-star wanted level. In GTA San Andreas, however, it is possible to entirely avoid police attention during a carjacking. If the player is in the process of pulling an occupant out of a vehicle and notices an officer nearby, they can just interrupt the carjacking. This is because the police officer will only respond if the player gets in the stolen vehicle; simply pulling an occupant out will not earn a wanted level.
In GTA IV, if the player attempts to steal an occupied car belonging to a gang member, other gang members of the same gang nearby will chase the player on foot and in car, usually using firearms such as pistols or SMGs to stop the player to retrieve their gang car back. It is very difficult to outrun a car chasing you, as they act like police officers on a 6 star wanted level, attempting to box the player in and gun them down. Unless you are desperate for a gang vehicle, stay away from them. This can also happen when carjacking normal non-gang members, but isn't as dangerous. In this case, normal unarmed pedestrians (such as homeless people, old women, and people who do not look gang affiliated) will attempt to protect/defend the one who is carjacked (who may or may not join in.) but as they are usually unarmed, they pose no immediate threat unless gang members join in.
If the player attempts to carjack a vehicle just as it begins to move and accelerates, the player will inevitably be thrown off, emphasizing the need to carjack only when a car is traveling in low speeds or is in a complete stop, however, in GTA San Andreas, if the player enters the passenger side of the vehicle, the driver may panic and begin to drive away, but CJ still gets in normally as if the car was stopped, making for a good boost of speed after taking full control of the vehicle (especially a ZR350 or a Infernus); likewise, any NPC attempting to drag the player out of their car may be met with the same experience if the player manages to bring their vehicle's speed up. In GTA IV, the proliferation of ragdoll physics allows for both the player and NPCs to be dragged along the road while clinging to a door handle after a failed attempt carjacking a vehicle which is beginning to move at a higher speed.