Nebula is a turn based strategy game of galactic conflict written by Julian Gollop. Players play the role of the leader of a race and try to expand and conquer the rest of the galaxy. Random events such as unrest and plague can create problems for each leader on their way to galactic supremacy.
Nebula can be played by up to five players, or a one player game against the computer. The game screen is split into two maps of the galaxy. The left hand map shows symbols representing each solar system. The symbols display which race inhabits the system, and the colour of the symbols denotes which player owns that system. A black symbol represents an independent system.
The right hand map shows resource levels and force points (troop levels). Cyan represents a resource level of 3, green 2 and magenta 1. The player that owns that system will receive new force points based on resource levels after each turn. The numbers on the right hand map show how many force points or troops are in that system.
Source: Wikipedia, "Nebula (computer game)", available under the CC-BY-SA License.