SDK Setup Tutorial

This page is based on the Dota 2 wiki.

Install the Alien Swarm SDK. In Steam, go to the Library section, and under Tools, download the Alien Swarm SDK. You can also click this shortcut link.

Extract Dota’s Files

Dota 2’s content files are distributed in compressed VPK form. You can extract them using GCFScape to later modify them in your game mode. You may need to use the x86 version, which works fine on 64 bit systems.

The primary Dota 2 package is the pak01_dir.vpk file under the base dota game directory. Open the pak in GCFScape, right click the root element, and extract the files to Alien Swarm\swarm\addons so they may be used in the Alien Swarm editors.

Rename the directory you have just created in the Alien Swarm addons to Dota2Extract.

Misc. Files

Copy the bin and platform directories into the Dota2Extract directory.

Finally, download dota2fgd (by RoyAwesome on GitHub) and UpVersion.exe (by ModDota) to the bin directory within Dota2Extract.

Alien Swarm Search Paths

Replace the contents of Alien Swarm\swarm\gameinfo.txt with:

        "game"    "Alien Swarm"
        "title"   "    "  // asw - leave this blank as we have a texture logo
        "type"    "multiplayer_only"
        GameData  "swarm.fgd"
        InstancePath   "tilegen/instances/"

        SupportsDX8     0

                "SteamAppId"  "630"
                "ToolsAppId"  "211"

                        "Game"  "|gameinfo_path|."
                        "Game"  "swarm_base"
                        "Game"  "platform"
                        "Game"  "|gameinfo_path|addons\Dota2Extract"

Configuring Hammer

Start the Alien Swarm SDK, select Hammer World Editor and let it open up. Now go to “Tools” -> “Options” and add the “dota2.fgd” from Alien Swarm\Swarm\addons\Dota2Extract\bin\dota2.fgd.

Next, increase the render distance so that the entire map will be visible at any given time. Under “3D Views” increase the Model Render Distance and Detail Render Distance.

Creating a Test Map

Under File, create a new map. Save it as test.vmf. Next, select File->Run Map and press “Expert” in the bottom left corner:

Click “Edit” and create a new config for Dota 2. We will define the build process as a series of commands.

The BSP Command

Click “New”, then “Cmds” and “BSP Program”. Add -alldetail -game $gamedir $path\$file.


Upversion is a tool that will convert the BSP into a format suitable for Dota 2.

Click “new” then “cmds”. Select “Executable” and find “UpVersion.exe” in Alien Swarm\swarm\addons\Dota2Extract\bin. If it’s not there, return t the Misc Files step and download it.

Add the parameters $path\$file.bsp $path\$file.$ext $path\$file.pbm.

Copy Map

Finally, to use the map in Dota 2 we will copy the compiled .bsp to the Dota 2 maps directory.

Click “new” then “cmds”. Select “Executable” and specify: CgWindows\System32\xcopy.exe, the built in Windows copy tool. Add the parameters: $path\$file.bsp "C:\Program Files (x86)\Steam\SteamApps\common\dota 2 beta\dota\maps" /y. Make sure the path is the correct path to your Dota 2 maps directory.`

Next Steps

You now have the Alien Swarm SDK set up properly to start working on Dota 2 game modes. You can follow the mapping tutorial in the next section.