Includes Production Buff (Red Flying Settler) Packed Wheatfield Artesian Well The Settlers Online: Castle Empire is the free-to-play browser-based version of the popular pc game series The Settlers by Ubisoft. The Massively Multiplayer Online Game (MMOG) Castle Empire combines all of the important aspects of the Settlers games. To make your citizens happy, you should build as many different buildings as possible and create working production chains to ensure an endless stock of resources. There is also the possibility to expand your empire by attacking other players with military force and claiming their resources and land as your own.