Weapons are at the forefront of all GTA games. Ranging from a fishing knife to rocket-propelled grenades to vibrators, there are many different weapons throughout the series. This article mainly concerns weapons in the GTA III era.
Weapon Skill
In GTA San Andreas, you can increase your skill for a particular weapon by practising, using the weapon either on a shooting range or on real targets. For each individual weapon you can achieve three skill-levels: Poor, Gangster and Hitman. On the Hitman skill level, you will be able to fire lighter weapons whilst walking, as well as being able to double-wield certain weapons (one in each hand).
Obtaining Weapons
Weapons can be obtained by three means. Firstly, a visit to Ammu-Nation will enable you to purchase certain weapons using your money, however not all weapons are available and the cost can be quite high. Secondly, you can kill an armed pedestrian, gang member or character and steal their weapon. Thirdly, once you have reached certain parts of games, such as obtaining a certain number of hidden packages, some weapons will spawn at your Safehouses.
This is a list of weapons and weapon types in GTA III era games. Not all of them are available in all games. They are grouped by the weapon slots from GTA San Andreas.