In a Draft Duel, two participants decide whether to open one or three packs of cards to stock their teams. In the first round of drafting, players select a card from the packs they purchased. In subsequent rounds, they get to see the remaining cards their opponent holds. The draft then alternates between selecting one from their stock of cards and one from their opponents.
This condition inserts strategic choice into the draft, whether to build the best available team round-to-round, construct a team around a specific player, or simply try to deprive your opponent of quality players at a certain positions.
The draft continues until a starting lineup is stocked (or filled out with random cards, if necessary). The teams are then rated, and the owner of the best rated team gets either a coin bonus or a pack of cards to use in a future Draft Duel. After the game, the winner gets a payout commensurate to whether the game was a standard, "premium" or "elite"-ranked Draft Duel. Regardless, both participants get to keep all players they selected.
Draft Duel packs come in bronze, silver and gold gradings, and must be acquired through the normal route—with Madden coins earned in Ultimate Team play, or bought for real cash. Everyone who begins the mode gets a free pack to try it out. The mode is only available on the Xbox 360 and PS3 versions of the game, as Madden NFL 13 on Wii U has no Ultimate Team mode. Game Informer has more information at the link.
Test Your GM Skills In Madden NFL 13's Draft Duels [Game Informer]