Well... Not really a whole lot to explain if you already know about the level system. Of course, I could go into an in-depth explanation of how it works, but I'd rather not. Long story short: LU Points were given an actual purpose with leveling.. There are certain check-points (if that's the right word) that once reached cause you to level-up. Now, levels in LU only provide slight perks, if any. For example, the level cap is 45, and when you reach it you start rebuilding with 8 Life and 20 Imagination (as opposed to 4 and 6, respectively). However, most of the rewards are clothes or accessories. So, in short, leveling is simply something LEGO is using to get people to play more often and for longer periods of time. Hope that helped. Edit: Fixed a typo... I hate those things...