Domain level

There is no actual value given to signify a domain's level. The power and regency of a domain comes from its holdings and their levels. A regent may have multiple holdings in multiple provinces of different strengths.
However, a domain may have a court level to define what the strength of its court is. This can influence its domain actions.
The term "domain level" is also used to refer to game-playing mechanics and actions that effect a player's management of their character's domain, rather than at the level of adventures or the character personally.