Built on a modified version of Valve's Source engine, Garry's Mod (or GMod for short) is a physics sandbox game.
One of the great strengths of Garry's Mod is that it is incredibly modder friendly. This has lead to a thriving community that is always coming up with new addons and gamemode for everyone to enjoy.
Create constructions with moving parts. Create a car and drive it around. Create a rocket and fly it to the moon
You can play Garry’s Mod with your friends online, allowing you to cooperatively build together
Garry’s Mod benefits from a rich productive community – so there’s always new addons to try
Installing addons is achieved in a single click
There are a lot of gamemodes to play, and trying them is as easy as joining a server