I'm a little unclear on the rivals mechanic. At the end of each global event when it shows you where you have placed there is an option to add other players that show up on the leaderboard to your "rivals" list.  When you do this does the person have to accept your rivals request or does it create a rivalry automatically?  Also, by adding someone to your rivals, is it the equivalent of sending a friend request or is it purely an in game mechanic so you can have some people to compete against in explore mode?

No way to delete your own topic?  I figured it out.