From Legacy Wiki
Referring is the process of inviting a new player for rewards. You can get many things from this new system. Some of the things are displayed on side chat or will give you an extra banner or clothing.
To refer, however, you need to agree to more Terms of Service:
Information
The referral system allows you to refer friends or visitors from your websites to the game and recieve a certain amount of awards for each one who signs-up. Some go bigger as you get along and some act as a pyramid.
Referral System Rules
1.You agree that everyone you refer will be an individual person, creating multiple accounts is punishable by ban and reset with the normal terms of service.
2.You may give the referral link to friends, put banners on your own website or post it on forums that allow it and do not consider such posts as spam it may be worth asking a moderator of the forum before you go posting.
3.Websites can now report any spam on their forums/newsgroups/emails. Any account found to be posting these links where they are not wanted, or emailing them to people they do not know to gain referrals may lose their account.
4.Do not refer anyone connecting from the same IP address as yourself, this means people using the same computer or work/school network as it may lead to confusion when we are checking for multi-accounts.
The referral system is here for the game and its players' benefit, any abuse of it will be treated strictly.
You get 50 credits minus 10 for each player you refer. So, the first player you refer you gain 50 credits, the next you gain 40, and then 30, etc. all the way to a base minimum of 5 credits.
There used to be a Top 10 Referrals List, back in the Hall of Records, rewarding a banner and a badge. But when the Weekly Top Ten Lists came in, it was deleted.