[Another person that hasn't heard of Action Duels... she guesses since he didn't recognize the duel disk, it makes sense.]

It's a new kind of dueling with mass introduced to solid vision holograms. "Duelists locked in battle, kicking the earth and dancing in the air alongside their monsters, they storm through the field!"

Basically, it's a duel style that favors physical interaction with one's monsters as they duel while seeking out "action cards", free-for-all spells and traps that can turn the tide of battle. All the kids in Maiami City train in this kind of duel.