Cepheus Engine and Traveller both have the same underlying themes. Players are involved in various aspects of living and working in a futuristic space adventure. Characters have a pretty open universe to visit. They have a large sandbox to play in. The players can do pretty much whatever they want to do in it. They can take jobs in order to make money. They can commit crimes or acts of piracy. They can explore or meet new alien races. The sky is the limit.
Exploration is but one possible theme for adventure. Exploration could involve mapping massive expanses of space. Or it could involve visiting new unexplored worlds. These worlds may be hostile in more ways than one. Is it a vacuum world? Does it have the same gravity as humans are used to? Does it have an atmosphere? Is it breathable air or poisonous to humans? Do aliens live there? Do humans? Even the plant life could be dangerous.
Moons, planets, asteroids, comets and even derelict space ships or space stations could be objects of an exploration mission.
Not every adventure has to be about combat. Exploring new territory is a fine way to spend an evening at the gaming table. Wondrous things might be found on such a world. Ancient alien civilizations might be found. Relics and artifacts from dead alien races might provide interest. Animal and plant life on such a world can be the object of exploration. Strange and valuable geological finds might create interest. Clues to the origins of humanity itself might even be found!
