Build r14675 (01/31/16)Planet is not depopulated after tank-only invasion with less than one million survivors.
From the design documents posted the other day:
If a planet is conquered, and the surviving population is less than 1: The result depends on whether or not any infantry is included in the attacking force. Assuming the attackers have surviving infantry, they disembark and take control of the colony. However, if the surviving attacking units include only armor, then he planet is depopulated in a vicious ground war. For game purposes, this is much like depopulation due to bombardment (see: Planets Destroyed by Bombardment), but, morale penalties that may apply in the bombardment case would not be applied here.
Conquered Akkeri II with nothing but tanks. 1.9 million people, 1 militia, destroyed during capture. Received the planet with 934,940 Yoral remaining. Uploaded as "game_780". The planet was not destroyed and eventually grew to be over one million Yoral.