A Glitch, also known as a Bug, is an error in the game that produces an effect that was unintended by programmers and appears in almost every game.
The Glitches often arise from mistakes or errors in the game's coding which go unnoticed during development and testing of the game. Glitches can be unintentional and may cause problems to the player, but some glitches may be used to the player's advantage.
Some glitches are prominent than others and each one are specified and/or shared on a certain console (where these depends of the console's technical aspects). One of the most popular and common glitches is nicknamed "Blue Hell", which is featured in every game since GTA III. Once the player enters Blue Hell, they will fall for 5–10 seconds before returning to the surface.
Disappearing Brass Knuckles Glitch
The Brass Knuckles will always disappear after saving the game.
Squashed Bike Glitch
Drive a VCPD Wintergreen to the stadium and buy access to the Phil Collins Concert. Exit or watch the concert. When the concert is over, there is a 75% chance the bike will be squashed. Vic can still mount the bike but it will revert to normal if he manages to do so.
Turn off-and on Glitch
Have a 2-star wanted level or more, then fly a little low in an area where the cops are chasing Victor. The police will arrest Vic in the helicopter even though he is flying.
Invisible Biker Glitch
Sometimes, if a battle with the Bikers is going on in Grand Theft Auto: Vice City Stories, shoot them with an Assault Rifle while they are riding fast and the Angel will perform donuts with no driver.
Invisible Vic on Bike
Get a bike, turn the camera into the outside dashboard camera. Try to look left and right, Vic will be invisible while riding the bike. If he have a sub-machine gun, the sub-machine gun is invisible and if shot at the front, it looks like a free aim.
(tested on PSP) Sometimes, cars appear where they are not supposed to. For example: at the bottom of a bridge, half in a building.
Building entry glitch
Sometimes, when Vic charges against a building without windows or doors in a car, he will end up in the building, but since the building was never designed to be entered, it is empty inside.
No traffic glitch
(encountered on PS2) After the eastern island is unlocked, if the player plays for a while without saving, in particular completing numerous Civil Asset Forfeiture Impound drop-offs in a row, they may encounter a scenario where no traffic (or, at least, very little traffic spawns). This does not affect pedestrian spawning, or the spawning of parked vehicles. There are some benefits to this glitch: less traffic to collide with when driving an Impound vehicle, and even up to a 6-star Wanted Level very few police or military vehicles spawn.
Police Helicopter Glitch
(tested on PS2) Whilst on a three star wanted level or above, going indoors whilst a Police Maverick is pursuing Vic will cause it to freeze in mid-air but with the propellers spinning. If the building has windows, Vic can snipe at the helicopter, providing it is in view, and it will catch fire after enough hits but will never explode. Exiting the building will negate the damage inflicted to the helicopter, although it will still remain stationary in the sky and can now be destroyed.
(tested on PS2) Head to the eastern side of Escobar International, where Vic will find a sand pile with a few cement pipes. Jump on the end of the pipe facing east, and it will teleport the player to the golf course on the first island.
Narrow Wrist Glitch
Enter Airtrain Glitch
The Airtrain is a big plane that is programmed to fly around Vice City by itself, as scenery prop. Due to a glitch it is possible to enter the plane, but the player cannot control it. The player can only cycle through the radio stations and enjoy the view. A video of it can be seen here.
No traffic and pedestrians Glitch
(tested on PS2) While driving a car, move the camera facing the top of your car by holding the right thumbstick up or down(depends if invert look is toggled on or off). If the player keeps driving over the road while holding the camera facing the vehicles' roof, no new cars and pedestrians will spawn. This can be used to go somewhere quick without having to deal with traffic, but the view is limited because of the camera.
Respawn at Leaf Links Glitch
(encountered on PSP) This glitch happens when you did not passed the From Zero to Hero mission. Go swim to Leaf Links near the bridge. After that you will die due to cannot pass trough the waves, your stamina will get low and you will die and respawn in Leaf Links. This glitch may happen when you repeat this many times or rarely.