Yu-Gi-Oh! Legacy of the Duelist is a Duel Monsters simulator, featuring a lengthy story mode that spans a number of seasons of the anime. Each season contains notable duels that the player can participate in. Upon winning those duels, the game unlocks "reverse duels," where the player can use the deck of an opponent such as Joey Wheeler in a duel against Yugi. The game features prebuilt decks to use in story mode based on the deck of the main character for that season. Players also have the options of building their own decks as well.
Source: User Summary
Main features include:
Relive past Dueling glory with a Story Campaign that recounts the events from the Yu-Gi-Oh! TV series! Battle your opponent, and then take on the role of that character and Duel against the protagonist in a “Reverse Duel.”
Duel with the latest cards from the official Yu-Gi-Oh! TRADING CARD GAME, including Pendulum Monsters!
For the first time, compete in Battle Pack Sealed and Draft play against the A.I. or with players online. Battle Pack formats supported include Battle Pack: Epic Dawn, Battle Pack 2: War of the Giants, and War of the Giants: Round 2.
Source: Yugioh Wiki - http://yugioh.wikia.com/wiki/Yu-Gi-Oh!_Legacy_of_the_Duelist