Our arena theme this rotation is Goblin Wars. Here are the rules on the deck:
1) Extended format. All bannings and Restrictions apply.
2) Minimum 30 creatures of one type in your deck and sideboard. (you could have 10 in your sideboard, and 20 main deck.)
3) No hate-cards/Mass-pump cards, for instance, here are some other banned cards in Goblin Wars:
Engineered Plague
Coat of Arms
you get the idea.
The three decks that are currently dominating Wednesday night are all controlled by the same person, who happens to be the store manager. The three decks are, Beasts (7-0), Goblins (6-1), and Clerics (7-0).
If you are looking for other fun formats, try these:
Godzilla (all creatures must be atleast 4/4)
Continuous Draft (open 3 packs, pull out one card. This card will never see play. Take the rest of the cards, and shuffle them toghether. You and your opponent lay out the top four cards, face up. You choose one, he/she chooses 2, you take the last one. Then he/she goes first, you choose 2, he/she takes the last one. Continue until there are no more cards. Build a 40 card deck, and play best of 3. Then, you move onto your next opponent, take out the lands from your deck, and shuffle your deck with his/hers. Continue until the store closes.)
Creatureless deck (name says it all)
That's the only ones I can remember. Oh, well. If I remember any more, I'll tell you.