Well folks, today we have a basic lesson in knowing your state's laws. Over on the World of Warcraft Arena Tournament Forums, Vertigan was wondering why Maryland was excluded from eligibility in the Arena Tournament.

Vertigan actually spent some time training on the Tournament Test Realm and was dismayed to find out that he was actually ineligible to play.

As you can probably guess (and which we verified by checking online), Maryland is one of the North American states where gambling is essentially illegal.

Since you're now participating in WoW tournament for a cash prize, you're also legally gambling. Since the arena tourney happens to be a form of gambling, it's also the reason why players have to be of the age of majority in their area.

Of course, this wasn't exactly the answer given by Blizzard reps. Bornakk replied
 to Vertigan's post saying,

Our legal team performed a detailed analysis of the way the tournament works and included all of the states whose residents would be eligible. We were also able to add some new countries to the Arena Tournament that were not eligible for our contests in the past. We continue to evaluate the eligible locations for our contests and will make additions in the future as we are able to.

We suggest that you make expressly sure you're eligible to participate in the Arena Tournament before you sign up. If you don't happen to be eligible, then there's a good chance your area's laws conflict with the nature of the competition.