Für Europa Universalis 4 steht die Download-Erweiterung Res Publica (Preis: 4,99 Euro) zur Verfügung. Das Add-on umfasst ein neues Herrschaftssystem (republikanische Diktatur) sowie ein Fraktionssystem rund um Aristokraten, Händler sowie Gilden.

• A Republic If You Can Keep It: Manipulate the factions of  Merchant Republics, create new trade posts and reap bonuses. You can also exploit the inner power struggles of the Dutch Republic and their unique election events
• Meet the New Boss: Try the all-new Republican Dictatorship government type, and decide between increases in national power or Republic Tradition through new in-game opportunities and events
• Don't Fight the Power: Retain power for the ruling family by backing your heirs in Elective Monarchies; boost your growth with the National