Sweepstakes and Contests Legal Speak
In a legal skill contest chance should be limited. Most states will accept some chance element. The skill must be a “bona fide” skill and there must be adequate standards. As a trivial question, if there is a tie, then skill must determine the winner not chance. A “bona fide” skill means that people who are skilled have a clear advantage over people who are not skilled.
I would suggest you include at least these three sections in any sweepstake or contest: void where prohibited, no purchase necessary, requirements for entry, where to find a complete set of rules, and when the contest will be over.