Cepheus Light is a set of rules for playing classic science fiction games. It includes rules on creating characters, resolving actions, fighting other creatures, and engaging in space battles, generating worlds, handling the risks of interstellar speculative trading, exploring new worlds, and many other activities. While rules-light and designed for fast, action-packed play rather than an accurate simulation of reality, Cepheus Light encompasses a wide variety of rules and materials for building a science-fiction universe and playing in it. Cepheus Light draws its inspiration from old-school science-fiction roleplaying games. It shares a lot of similarities with these games. Material from older rules sets and those created with Cepheus Light, the Cepheus Engine Core, and old-school sci-fi roleplaying games are easily compatible with only a moderate amount of adjustment. The future awaits! Compatible with the Cepheus Engine System Reference Document and other OGL 2D6 Sci Fi games.