From the Fable Wiki:
The game is set 400 years before the events of the first game, in a time before the Heroes' Guild was founded. Heroes are common, but the people of Albion are only just learning what a true Hero can be. During this time in Albion's history, an ancient artifact exists called "the moon on the stick", an artifact that the children of Albion once made wishes to. The heroes in Fable Legends are on a quest to locate this artifact.
The game is based around five players: four heroes, and a villain. The AI controls the characters in the absence of a human player. The villain player controls the nature of the quest the hero characters embark on, such as where enemies will spawn, how aggressive they are, when the boss will come lumbering out of its lair, when to bring down an impassable portcullis or lay a trap to separate heroes from each other to thwart them. The villain earns points over time, which can be spent on units. Two of the playable heroes have been identified so far, a Prince Charming type of character, who flourishes a rapier and wise cracks, and Winter, who is focused on will-based abilities.
Unlike other games in the series, Fable Legends is essentially a dungeon crawler, with little in the way of villager interaction, purchase of property, morphing due to alignment, etc. However, the player can customize their hero's weapons, looks, armor, abilities and more. Like many other games in the franchise, heroes can also use expressions to interact with villagers. In the hub-city of Brightlodge, players have the opportunity to partake in jobs, play mini-games and enjoy pub games. Once the player selects a quest, they are immediately sent out into the world.
The game is intended to have a 5-10 year life-cycle, and will be intergrated into the cloud features of the Xbox One. SmartGlass features will allow villain players to make their plan of attack before a quest