Board Thread:Questions and Answers/@comment-24071602-20141011230416/@comment-25012056-20141012165547

This is what I have discovered, in short:

The code is basically the probality of the invasions. Every 20 ticks it runs through and computes the chances based on the rarity of each invasion.

Hope it helps, Gen. Grievous1138 (talk) 16:55, October 12, 2014 (UTC)