I know Fizzer has posted a link to the rules a few times but this is the best I could find.
Here's a link to the thread where I found the rules: http://warlight.net/Forum/Thread.aspx?ThreadID=837
The rules I copy/pasted that might well be out of date:
1) You shall be respectful to other players at all times.
2) Racial slurs, personal attacks, excessive profanity, or any other offensive language will not be tolerated.
3) You shall not operate more than one WarLight account in a way that gives you an advantage in a game or tournament.
4) You shall not impersonate other people or use anyone else's account without their permission.
Any violation of these rules will result in suspensions or banning