I've always interpreted lotteries as any game of chance, but in reading the section noted by David, it seems that there needs to be an exchange of money or credit to be termed a lottery. If the entrees are made available to anyone and there is no exchange of money or credit, does the Federal Law still prohibit the contest?
See below-excerpt from the citation:
c) Definitions
As used in this section—
(1)The term “deal in” includes making, taking, buying, selling, redeeming, or collecting.
(2)The term “lottery” includes any arrangement whereby three or more persons (the “participants”) advance money or credit to another in exchange for the possibility or expectation that one or more but not all of the participants (the “winners”) will receive by reason of their advances more than the amounts they have advanced, the identity of the winners being determined by any means which includes—