It is possible that a civilization signs a research agreement for the sole purpose of getting an enemy to spend money that could be used for other purposes; AI civilizations are programmed in such a way that they sometimes use this tactic before declaring war.  British actor W. It is easy to defend in your own country if you have enough troops. Notice how I set up a fortified line in one of the screenshots above to protect my country. Babylon has been quite friendly, but things can get worse if you start earning by building spaceship pieces. Castles, etc. in your cities, are also a deterrent. In this game, I was able to build Neuschwanstein that favors a little defense and offers happiness in the melody of 8-10 in total for 3-4 cities. The money you put into the agreement is lost. That`s not necessarily a bad thing – if you can put someone in a research agreement before they go to war, they`ll lose the money they could have used to defend themselves. Conquered cities can be annexed, destroyed, or turned into a fanatical state, with each option having different advantages and disadvantages. .