To clarify, LAS is somewhat unique in that the priority lane at security is for bona fide First Class passengers only (that is, those holding a boarding pass with a First Class seat assignment), and not for any other type of passenger. Other ways to use the priority or "first class" security line that work at most other airports, such as a having a certain elite status, a certain credit card, or otherwise having "elite access" or some similar designation on your boarding pass but with an economy seat assignment, do NOT work at LAS.