The Birthright Campaign Setting (1995) is a unique, high-fantasy Advanced Dungeons & Dragons 2nd Edition setting. Focused on political intrigue, ruling domains, and "bloodlines". Set in Cerilia, players often act as rulers managing lands, leading armies, and exercising divine magical power rather than just being adventurers.
Unique among Dungeons & Dragons settings, Birthright can be played by 2+ players by design. If you are a fan of World building, setting flavor, and turn based strategy games; Birthright is an amazing supplement.