Please help with verifying or updating older sections of this article. At least some were last verified for version 2.8.
Republic is a government type in which the ruler is elected from the citizenry, via the Open Elective succession law. Because there is no dynastic persistence between rulers, Republic governments are not playable. They are the government type of cities.
In general, ruling over republics is similar to ruling merchant republics, except for a few key differences. While not as powerful, and unable to create trade posts, regular republics actually pay more in taxes to their liege lords and aren't quite as dangerous to their lieges.
A republic can have its government type changed in two ways:
First, to change a grand city into a merchant republic, the grand city must have a coast. Granting a coastal grand city a ducal title will create a merchant republic. If it can, a republic will create a ducal title by itself and transform on its own.
To change a large republic into a county or a theocracy, a king would have to revoke its primary title, then bestow it upon a baron or count within the borders of the republic. Having control of a feudal holding within the republic will automatically transform the republic title into a feudal title.
To prevent a republic from becoming a merchant republic, its best to hold a de jure ducal title directly above their county. This will stop them from creating it themselves.