I hope this can get pinned as I believe it will help alot of those who are a little new to their firewalls, or have never touched them.

http://www.portforward.com/

In short:

1. find your firewall model and select it from the list. (most DSL customers it is your modem)

2. Select the program you want to setup a forward for ( as this post demigod has not been added, but I already submitted a request to get it done)

- alternatively -

after you select your model look for a link that says "Default Guide" in orange in about the middle of the page. This will give you walkthrough of how to do it.

PS : if you are in the western US and have QWEST please note that they use a custom firmware. I am sure this is similar for most ISP's. Find your model and read through the walk through, it should give you enough of an idea of what you need to do.

As  good measure I would go to (default install path) C:\Program Files\Stardock Games\Demigod\bin\ImpulseReactorOptions.exe and make sure you input the values 6100 - 6200

Also a post I had answered on doing multiple users behind the firewall wanting to play is at http://forums.demigodthegame.com/350619