I want to buy Europa Universalis: Rome Gold, but I'm not sure if it will run in Linux.
Assuming you're going to buy it through GOG, it should run fine according to WineHQ
, where it has a Gold rating.
Additionally, there is an installation script available on Lutris
if you're not comfortable with using WINE directly.
As for the Steam version, ProtonDB
gives it a much poorer Bronze rating, although there are several reports on there where users rated it Gold after applying a couple of minor tweaks.