You are the head of a respected but troubled family estate in mid-19th century England. After several difficult decades, the family's fortune seems to be improving! Your goal is to enhance your estate to be in a better position with the truly influential families in Derbyshire.

Obsession is a game of 16 to 20 rounds in which players build a bank of members of the English aristocracy, renovate their estate by acquiring building tiles from a central builder's market, and manage an extensive service staff, including butlers, housekeepers, footmen, maids, valets, and servants, using a new worker placement mechanic. Successfully hosting prestigious social events such as hunting trips, musical readings, billiards, political discussions, and grand balls increases the player's wealth, reputation, and relationships with the elite.

Each round, players choose a building tile that represents a room or outdoor space around the 19th-century English countryside. The chosen tile determines the event that can be hosted and the guests that will be invited. Players must carefully plan to have the appropriate staff available to serve the event and support the guests as needed. The reward for success is new investment opportunities, allowing further estate renovation (acquiring more valuable or powerful building tiles), increasing reputation in the county, expanding the circle of influential acquaintances, and a larger and highly trained staff.

Throughout the game, a competitive bid for the hand of the most suitable young men and women in the county highlights specific renovation and reputation goals. The player who best meets these goals by collecting victory points will win the hand of the wealthy interest and the game.