Garryho Mod -

While the single-player sandbox is great for learning, the game truly shines in multiplayer and with community mods: Guide :: Gmod: How to have fun - Steam Community

The core of GMod is building. You can start by spawning basic props and "welding" them together using the to create cars, rockets, or even complex robots. Garryho mod

Garry's Mod (GMod) is a creative sandbox game where you can manipulate objects, build contraptions, and explore countless community-made game modes. Because it is based on the Source engine, many of its mechanics will feel familiar if you have played games like Half-Life 2 or Counter-Strike . Essential Controls While the single-player sandbox is great for learning,

: Use the Undo (Z) key to quickly remove the last item you spawned. Because it is based on the Source engine,

: Hold Q to open the menu where you can spawn props, NPCs, and weapons.

: You can save your creations or download "Duplicates" (Dupes) made by other players through the Steam Workshop. Multiplayer and Add-ons

: Press V to fly and move through solid objects, which is essential for building and fast travel.