Twenty-four planets speckle the tiny galaxy of Insyllium. These planets have been jointly ruled for an eon by five appointed Viceroys. Each player has a new vision for the galaxy, and will manipulate the Viceroys and their Agents in attempts to conquer the planets of the galaxy using a variety of devious methods. Insyllium is played over series of rounds, and each round is broken into several parts, or phases: Viceroy Phase, Agent Phase, and Cleanup Phase. During a round, players will draft a Viceroy and an Agent, and attempt to gain control of new planets through a variety of devious methods. Players score points based on the planets they control as well as any completed objectives.