I read that sometimes, a star's first planet is missing, because it's orbit was too close to the star after generation. That makes sense.
However, I notice now, that in quite a lot of systems, there's also planet numbers missing in between.
For instance, the system I just explored, has planets I, II, IV, V, VI, VII, IX, X and XV.
That means, III, VIII, XI, XII, XIII and XIV are missing.
III and VIII can be explained, as they have asteroid belts in their place. Which also makes sense.
But what stellar mechanism made the planets between X and XV go missing?