From Astro Wars
Planets are numbered within each system. The planet's number is its Planet ID, and is used when launching fleets. Planet IDs will always be numbered 1 through 12. Some Systems may have fewer than 12 planets when they are first created; this is due to the amount of players in that system.
Each time a player joins the game, he or she is allocated a Home Planet to start on, and two adjacent planets are created as Free Planets in that system. Should another player join the game, three more planets will be added to the system, and so on, up to the maximum of four players and twelve planets.
The first person to join a new round is spawned on Rana 2 and is surrounded by an empty Rana 1 and 3. The next person to join is placed on Rana 5, creating Rana 4 and 6 also. Person No. 3 and 4 are on Rana 8 and 11, respectively, and Rana 7, 9, 10, and 12 are created as empty planets. The Fifth person is placed on Achird 2, since Rana is now full with 12 planets.
- If a player should resign or be defeated, his or her planet(s), and any additional 'free planet'(s) will remain in the system. Planets once owned by a resigned player will be marked Unknown and will retain any buildings, PPs or fleet already present.
- As of Gold 21, some systems are spawned with 12 empty planets