Basically this is a fairly self explanatory game. The first person to get the last post (that is, the final post and not simply the latest post, as that will always be changing) in this topic wins. The topic will end when the final post is posted. Losers are then encouraged to congratulate the poster in this topic, thus making the winning poster lose(?) and making a losing poster win(?).
Confused yet? Now you understand exactly how it works.