Jarls are the rulers of Rothurland. Each jarl controls a part of Rothurland, called a jarldom, for as long as they are able to maintain their grasp. Rulership is usually highly contentious, with challengers to the jarls both inside and outside their realms. In this autocratic form of government, no standard method of succession exists. Some jarls manage to pass on their lands to their children, or to trusted friends, but if the new ruler is unable to keep control through force, or less likely through diplomacy, then they soon find their realms divided by their rivals.
Jarldoms are not fixed areas, like provinces or hereditary lands usually are elsewhere. Rather, they change regularly to reflect what a jarl is capable of controlling. If two jarls lay claim on the same territory, the inevitable conflict determines whose jarldom it falls within. Conflicts of these sorts may involve combat, but are just as likely to be resolved by trickery, payment, or some other method. Jarldoms usually follow natural geographic boundaries, but not always.
Occasionally the term jarl is used to refer to tribal leaders of western Talgazan, especially those of giants, but otherwise it has little use outside of a Rothurlandic context.
Certain regions within Rothurland, notably the mountainous interior of Icepeak Island, have historically managed to remain free of the controls of any jarls.