Main Menu


Where can I find support information for DEFCON?


Please review the Third-Party Game Support topic to determine whether your question should be directed to the game developer or to Steam Support. Sending a support request to the wrong party may result in a delay in processing your request.


Retail CD-Keys for this game cannot be registered through Steam. If you wish to create a shortcut to this game under your Library, instructions can be found here:

Adding non-Steam games to your Library


DEFCON Support Site

DEFCON Support Site


Steam Forums for DEFCON

Steam Forums


Contact Introversion Support

Introversion Support


DEFCON Connectivity Issues

DEFCON uses the following Network ports (by default) for multiplayer games:

  • 5008 (UDP) - MetaServer (public server listing)
  • 5009 (UDP) - MetaServer (public server listing)
  • 5010 (UDP) - Game Server
  • 5011 (UDP) - Game Client

Use Steam ports for DEFCON

You may change the default connection ports for DEFCON to match the Steam connection ports if you are behind a proxy which is blocking DEFCON's required ports:

  1. Exit DEFCON and log out of Steam
  2. Locate your DEFCON game folder (by default it will be under your Steam installation folder\SteamApps\common\defcon\ )
  3. Open the preferences.txt file
  4. Locate the following settings:
    NetworkMetaServerPort = 5009
    NetworkServerPort = 5010
    NetworkClientPort = 5011
    NetworkUsePortForwarding = 0
    NetworkTrackSynchronisation = 0

    Change these lines to:

    NetworkMetaServerPort = 27020
    NetworkServerPort = 27020
    NetworkClientPort = 27020
    NetworkUsePortForwarding = 1
    NetworkTrackSynchronisation = 0
  5. Save the file, log back in to Steam, and start DEFCON

Problem with this game?

Contact Support

Problem with Steam?

Contact Steam Support
Related Articles
DEFCON Third-Party Game Support
DEFCON Add Non-Steam Games to a Library