1. The actual project.
2. The rewards doled out to supporters of the project.
The Kickstarter rules are very clear about the following things: 1. The rewards are a contract. If you fail to deliver
the rewards on whose terms the backers supported
you, you're legally liable.
2. The rewards may be delayed, as long as regular
communication about the actual progress happens.
Thus the project itself can fail, as long as you make sure the rewards are given out.The fact that most project are confident/stupid enough to offer rewards that can only become reality if the project succeeds has muddled this reality in the mind of the average person, but the rules and legal realities are crystal-clear.