I'm playing in Omega world and last night (i.e. 9 hours ago) tried to take a ghost town by attacking with a colony ship with supporting naval and land units. An error showed that I had to have research conquest. I thought that if a ghost town was cleared (which it is) you didn't need research conquest to take it. The ghost town is diedel12's city. I looked at previous postings here and it said that. Not sure what is going on here. I'm playing in Delphi world and took a ghost town without research conquest. Am I missing something here? Thanks! By the way, I do have the culture points to take another city.