A young system is one still forming. Most of its mass is in many small bodies on stretched, crossing orbits, each a single mixed layer, with few planets or fields. The small bodies are not spaced clear of each other, so they meet during play: accretion merges gentle meetings, collision breaks hard ones, and moon capture puts a light body passing close to a much heavier one into orbit around it. The system changes as the game runs.
YOUNG SYSTEM
NOTE> STATUS reference note.