User blog comment:Witnessme/Creepypasta Short Story Contest/@comment-24466828-20151008190724/@comment-25170312-20151008191157

It's a very common thing with contests. Probably some legal mumbo jumbo. Even when it's a contest for kids it will says "must be 18 years old so get your parent's permission, yadda yadda". It could also be because of the trip. They'd have to send you with a parent or guardian which would make it more expensive. Or it could be that the movies are rated R. Many possibilities.