Blood Enemies: Abominations of Cerilia

Birthright is a Dungeons & Dragons campaign setting that was first released by TSR in 1995. The setting is based on the world of Aebrynis on the continent of Cerilia, in which the players take on the role of the divinely-empowered rulers, with emphasis on the political rulership level of gameplay. In 1996, Birthright won the Origins Award for Best Roleplaying Supplement of 1995.

The setting revolves around the concept of bloodlines: divine power gained by heroes and passed to their descendants. Characters with a bloodline create an aura of command known as Regency, which is measured in the game using regency points or RP. Using regency, characters acquire a domain composed of provinces and holdings. The development of these domains is as much a part of the game as development of the characters. The game uses three-month domain turns to model actions of rulers over nations in much the same way as Dungeons & Dragons uses combat rounds to simulate time to model the characters' actions in battle.

In 1994, Rich Baker and Colin McComb co-designed the Birthright campaign setting.

Matthew Pook for Pyramid magazine recognized the campaign as the first setting to support player characters as rulers, providing players with a game based on "diplomacy, politics, trade, construction and (of course) war".

According to writer Michael J. Tresca, Birthright was inspired by Tolkien's Middle-earth setting, as a "universe profoundly influenced by bloodline, nation building, and war".

The world of Aebrynis has at least four known continents, the frozen continent of Thaele, the continent of Djapar to the southeast, the great southern continent of Aduria, and Cerilia, the location of the actual Birthright campaign. Cerilia itself is divided into five regions: Anuire, Rjurik, Brechtür, Khinasi, and Vosgaard, each named after the primary human group that first settled there.

Anuire is in the southwest portion of Cerilia. To its south are the Straits of Aerele, which separate Cerilia from Aduria. To the west lies the Sea of Storms (Miere Rhuann) and to the east the Gulf of Coeranys. The river Maesil forms a great highway through the heartlands of Anuire. Generally a temperate climate similar to Western Europe. Conceptually similar to England during the War of the Roses.

...
Wikipedia