Here are a few examples of Dragon Castle layouts. To build these, you can use the "blank" Central board. Nevertheless, we also encourage you to be creative and make your own! As a general guideline, castles for 2 players work better if they have between 65 and 80 tiles on the ground floor.
Castles for 3 players should have 50-70 tiles on the ground floor.
Finally, castles for 4 players need approximately 40-55 tiles on the ground floor.
On top of that, regarding the two upper floors, we strongly recommend that you avoid having too many rows of tiles with a lot of adjacent tiles (6 tiles or more). With too many such rows, there's a risk you won't have enough Available tiles on the upper floors during the game.