There are two players. The Imperial player (red counters) sets up first, with two corsairs, three orbital bases, and three dummy counters. All counters are placed upside-down, stationary, on or adjacent to any asteroid hexes.
The Leix player (blue) gets ten packets. Each packet starts the game in orbit around Terra, Luna, Sol, Venus or Mercury. These starting positions represent various possible spots near the sun Leix B. To represent the heavy planetary defenses, Sol and each inner planet may attack as an orbital base (strength 16) if an Imperial ship comes in range. Sol and the planets may not be attacked.
Substitute counters as necessary, since the game's counter mix does not include (for example) ten packets of any color.
Mars does not exist at all. Neither do the asteroids (except as Imperial setup markers). Jupiter and its moons exist and have gravity. Sol and the inner planets exist normally for game purposes, though they do not represent separate bodies.
All units begin the game undetected. An Imperial unit is detected when it first moves, or when a packet comes within three hexes of it. A packet is detected when it first burns fuel afterleaving orbit, or when it comes within 3 hexes of an Imperial ship or base. Dummies do not detect. Once a ship is detected, it stays detected unless (for a packet) it returns to an inner-system orbit, or (for Imperial ships) a "re-set" is achieved - see below. Detection occurs at the end of movement, but before combat.
Packets may undergo one overload maneuver, and then require minor maintenance. The same is true of Imperial ships in the basic game. Refueling and minor maintenance take place (for packets) in an inner-system orbit only, and (for Imperial ships) at orbital bases, or after "re-set."
Imperial corsairs carry one mine each, which may be replaced by rendezvous with an orbital base. Imperial bases are detection stations only, with no combat strength. Packets have a strength of 1 (as printed in the rulebook) rather than 2 (as printed on the counters).
Imperial units begin the game motionless, and may not move until at least one packet is detected. They may not attack, or deliberately move toward, an undetected packet. However, a packet may maneuver to avoid any Imperial unit, detected or not. This will itself allow fuel to be burned, letting the Imperials detect the ship, but can be worthwhile. The game ends when no packets are left on the board.
If at any time there are no surviving packets on the board outside the five inner-system orbits, the Imperial player may remove all his units from the board, replace any lost dummies, and set his units up again. All units are inverted and motionless, as per the original setup rules. All ships are automatically refueled and given minor maintenance, and corsairs get new mines if needed. All ships are now undetected.
The Imperial player seeks to destroy as many packets as possible; his own losses are not important. The Leix player seeks to get as many ships off the top of the board as possible. To successfully exit, a ship must have at least five fuel units (half its original store) left, and may not be disabled. If seven or more packets successfully escape, the Leix player wins. Six is a tie. Five or fewer is an Imperial win.
Players will soon discover one or more maneuvers to allow a near-certain Leix victory. At this point, add the following complications, starting with the first and working up.
And so on . . . any of the above may be further balanced in favor of the Leix player by letting packets fight at their printed value of 2 - or in favor of the Empire by turning all the packets into unarmed transports.