The city of York is being built. Many buildings have already been built, but without a protective outer wall to defend against the Viking raids, the city is bound for failure. The king has called together his best architects to design defensive walls for the city, but only one's design will be used. That architect will be hailed as the greatest architect in all the land.

In Walls of York, players must use the plastic wall pieces to construct a defensive barrier around the buildings on their city map. Each turn, a player will roll the Building die, which will dictate what types of walls are to be used. Players must Enclose their city, containing the required buildings from the King's Decree. But players must beware, for the Vikings will come and lay waste at the end of the first Age, forcing player to build anew in the second Age. The player with the most coins at the end of the second Age is declared the winner.