From the Official Rules to EFF's Defcon 18 Getaway Contest (emphasis mine):
By participating in the Contest, you agree to release EFF and its employees, directors, officers, fellows, interns, staff dogs, and agents from any and all liability, claims or actions of any kind whatsoever for injuries, damages or losses to persons and property which may be sustained in connection with the receipt, ownership, possession, use, or misuse of any prize.
Also from the same source:
By participating in this Contest, you acknowledge and agree that Han shot first.