Simply put, your Castle Level is your overall score in the game of CastleVille. It’s the number that is used to rank you against your neighbors and friends in the game. The more Castle Level you have, the more powerful and healthy your Kingdom is. Your Castle Level is displayed in the top right corner of your screen, next to your energy bar. It also appears on your player icon in the friend/neighbor bar at the bottom of the screen. This is where you can view the scores for your friends as well.
In addition to being the primary ranking score for players, Castle Level is needed to fully explore the map. Each area on the map requires a certain amount of Castle Level in order to be explored, and some areas have very high requirements.
Growing Castle Level
The main way to grow your Castle Level is to construct Royal Buildings. These buildings each provide a certain amount of points towards your overall level. Furthermore, as the buildings themselves “level up” with repeated tending to by their staff (your friends and neighbors) each building will add additional level points to your overall score. Additionally, you can grow your Castle Level through certain decorations, like castle walls and towers, but the amount that comes from decorations pales in comparison to what you’ll get from Royal Buildings.