Site terms of service legal age requirement is 18+. Why are many promotions 21+

You are allowed to register an account if you are 18+. Most tournament venues in the United States, minimum legal age required to enter the venue of where the tournament is held is 21+. You must be 21+ to participate in the promotions that state 21+. If you participate and win a prize when you are not of legal age for the promotion. Prize will be forfeited and awarded to the eligible member.