Map Pack 1 DLC can be purchased to gain 9 new Maps to play.
It contains Map 10a-10h and 11.
There are new addditional settings to choose a map (depending on the game modus):

• Choose a map from a random group of maps in-game
  
• Assign a map to each player in your group in the matchmaker
  
• Or let everyone choose freely which map they want to play in-game

Owning the base game of Castles of Burgundy is needed to play.