If you come back from Rampage having ridden your lines and not broken either your bike or yourself, you're pretty much winning already. The Rampage is a contest however, and as such, somebody needs to be on the podium at the end of it as well. This video explains what the judges are looking for when scoring the runs:
Credit: Red Bull
Control and Fluidity
Tricks and Style
Finals are going down later today, with live coverage online, be there or be square!