Has anyone ever seen AI use troops and capture a planet

[Noble713]

I've been invaded by the AI ONCE. It landed 3 large or medium troops on a totally undefended planet and captured it.

I wish troops couldn't be killed from orbit without damaging the facilities and population. This would make them far more useful for defensive purposes. I'd really like to see some troop vs troop battles, complete with stalemates and contested planets. I had a contested planet once, and when you go back to the main screen it has a little message on the planet saying it's contested and whatnot. Unfortunately I promply re-invaded so I don't know what happens to a contested world when the AI's turn comes around.