How to activate a Riot key?
Activating a Riot key is really easy, simply follow these steps:
1/ Log into League of Legend user or go here to register.
2/ Move to Store tab.
3/ Select "Purchase RP" in upper-left corner.
4/ Choose the "Prepaid Cards" option and put your code in.
5/ Click on "Submit" and your Riot Points will be added to your LoL profile.
6/ Return to game client site.