Instructions:
1) Follow the link below
2) Click on button that says "Join Your Friend"
3) Create free account
its good for 7 day trial (no code required)
enjoy and hope to see you in the game!
http://www.riftgame.com/en/products/ascend-a-friend/invite.php?voucher=7ZLZYJPEGEKT9CK6QEZK