sorry, but is this the main issue? aren´t you trying to break the game´s mechanics/laws here? i´m not an expert in these vassalage features... but if "vassals and masters can´t exchange cities", shouldnt you have taken that into account during your player-to-player negotiations? and now you are asking us to sign a 10-turn peace deal? please let me know if i´m not getting this right @Nighthawk and the rest: any comments on this?