Armies can be sent between kingdoms for a large coin cost and will take 2 hours to move but can be sent immediately with rubies. Resources can also be sent between kingdoms for free but a percentage of resources will be lost on the two hour journey. The resources can again be sent instantly using rubies.
The Robber baron castles get stronger on each kingdom (starting at leve; 20 on ice) but pay out a greater reward for being defeated. The robber baron fortresses on ice, sands and fire pay out a very large number of resources, coins and rubies- they are similar to the Robber Robert event in the great kingdom. You are attacked by the robber baron castles on these kingdoms with stronger soldiers but they don’t use tools and so can be defeated very easily if you use tools
There are new quests which make levelling up much quicker. These quests are similar to the ones in the great empire.