A VMAP file is a map file created by the Valve Hammer Editor, a tool included with the Source SDK and used to create maps for games using the Source 2 engine. It contains a map, which may include lanes, ancients, fountains, barracks, runes, shops, neutral camps, towers, and other map elements. VMAP files are compiled into binary .VMAP_C files, which are then used in a game using the Source 2 engine.

VMAP files are typically seen only by DOTA 2 gamers who want to modify playable maps. VMAP files were introduced with the release of the Source 2 engine and replaced .VMF files, which are used by games with the Source 1 engine. VMAP files are most commonly used by DOTA 2 but may also be used for other games that use the Source 2 engine. You can create and edit VMAP files with the Valve Hammer Editor, which is included in the Source SDK and DOTA 2 Workshop Tools. After you are done modifying a VMAP file, you must build it into a compiled map (VMAP_C file), which is packaged in a .VPK file. Select File → Build Map, choose your settings, and click Build to compile the VMAP file.