Europa Universalis 4 continues to sprawl like my historically inaccurate British Empire (sorry, France, but I think we can agree that Paris was fair trade for Calais). So far, EU's expansions have improved warfare, granted the ability to play as colonial nations and introduced Common Sense. Now, the unblinking eyes of Paradox Development Studio have turned to the seas for Mare Nostrum.
In Mare Nostrum, no longer will you construct self-piloting ships, instead recruiting sailors from coastal populations to keep them on course and ship shape. That could prove a headache, so Paradox is adding a mission system to simplify naval management—a godsend to anyone with a trade empire, which will get the ability to form economic alliances too. If you want to play lord of the Iron Islands, Barbary Coast nations can raid their neighbours for gold and conscripts, although I can't see them being happy about it.
Away from the coast, those of you with massive, anachronistic standing armies can rent out your soldiers as mercenaries to beleaguered states, and you can request intel from other nations to roll back the fog of war.
Diplomacy and subject nation management are due yet another round of changes, plus the release of Mare Nostrum will be accompanied by a free patch for all.
Mare Nostrum hasn't been dated, but I'm ready and waiting to pick on countries too small to build galleons.