Sorry for necroing but is an interesting subject...IF the de-vasalization option can be done interface-wise it also must have some kind of penalization for realism and fairness IMO...like a relation penalty with every other nation for...lets say...3 points? with the excuse of "You didnt respect a vassal contract" or something like that PLUS 5 points with the de-vassalized nation with the same excuse AND worst penalties if you both are at war...(maybe the same penalties mentioned before plus a 30 turn -5 happines across your nation) But for all this to make any sense there should be a bonus to having a vassal state on the first place...a REAL bonus of some kind...one option is to use the vassal to work for you in an area you chose...and make it REALLY usefull...like giving the vassal the order to research for you (not specific, just a sub-menu to force it to choose if research-gold-espionage-suggestions?) then that research gets ADDED to your own research without the need to sharing previous project with said nation...and make it a percentage of the mass production he can spew maybe? so if that nation is in renaissance and you are in modern age then they add for a minuscule amount of research... I can think of other options to add but...maybe im dreaming to much...way to much Vassal system need some love...thats something a lot of ppl agree EDIT: should i post this on the ideas thread?