The rocket launcher is an extremely powerful weapon, capable of destroying almost anything capable of being damaged. The advantages of this weapon are its power and range, with its blast being capable of inflicting heavy damage from several meters away. The warhead self-destructs after traveling a distance, limiting it's range. The disadvantages are slow aiming and the propensity to seriously damage one's own health by accidentally hitting a nearby object.
In GTA III and GTA Vice City Stories, the rocket launcher resembles a US Army M72 LAW rocket launcher with a few aesthetic differences (the weapon is held by a handle on the bottom and fired through a scope, something the M72 LAW lacks in real life).
In the rest of the GTA III Era (GTA Vice City, GTA San Andreas & GTA Liberty City Stories) the rocket launcher resembles a Russian RPG-7 portable anti-tank rocket launcher.
Cedar Grove, Shoreside Vale - On the west side of the roof of the large pink house at the west end of The Homes (closest to Cochrane Dam). To get this weapon icon, wedge an Ambulance under the lowest part of the roof on the east side of the house, climb the Ambulance then to the roof, then go west along the south side of the roof to reach it.
In GTA IV and The Lost and Damned, the rocket launcher again resembles the Russian RPG-7 portable anti-tank missile launcher, it is not fitted with the PGO-7 optical sight usually seen on the launchers. It is the only heavy weapon available.
The Rocket Launcher can be purchased at the back-alley gun shops for $15,000 and each rocket will cost $5,000. The Rocket Launcher cannot be obtained from Little Jacob.
Locations
Northwood, Algonquin - Can be found on a large boulder in the water north of Northwood. This is the easiest RPG pickup in the city.
Castle Gardens, Algonquin - Can be found in an alcove on the southeastern partition of the construction site seen in the mission Deconstruction for Beginners. The RPG is inside an alcove facing the water, and can only be reached by boat or by cafeful helicoptor.