Mare Nostrum adds some very helpful features to new EU4 players who are just starting out, one of the main ones being the ability to assign missions to your fleet to reduce the micromanagement. The trade leagues can be fun to mess with as a nation like Venice that benefits from it and the ability to rent out your armies is helpful in multiplayer. I rarely use the map sharing feature but it definitely has its uses. Overall, at its current price of 6.75 its really not a bad idea to pick it up.

The dlc doesn't add much, some naval missions I didn't really use, and some events. the only cool thing was the timeline. buy only if there is a sale

I have been a long time fan and player of the Europa series, since EUII in fact. I have put in well over 1000 hours in the EUIV alone. Is this dlc worth getting and does it add to EUIV? Well I guess that really depends on the person. Mare Nostrum adds some great content to an already great game. For a long time I thought it was lacking that you didn't use up manpower specifically for use with your ships. You get sailors to recruit to build your ships along with additions such as raiding coastlines for supplies, extra missions for fleets, renting out land armies to other countries to make extra cash, especially if you are a smaller country can be VERY helpful. You also have new espionage actions, merchant republics can create trade leagues, etc. The big thing to take away here, does this DLC give you great content? Yes! Is it worth 15 dollars for the content it brings? NO! I love EUIV dearly and I generally like paradox for the games they create, however I do not agree with their pricing of DLCs as of late. When this DLC along with the content pack that goes with it goes on sale for around 50 to 75% off, then YES this DLC is worth and the price and the content it brings. That is what I did and have not regretted my purchase.

Mare Nostrum is the eighth and, currently, is newest expansion for Europa Universalis 4. This DLC adds new features for navy units such as new missions for navy ships (creating blockades), the ability to raid coastlines for supplies, and coastal provinces provide you with sailors that are used to man and repair ships. The changes make fleets easier to manage but more difficult to create with the new needed resource of sailors. Nations are given the ability to rent out armies to other nations, a set amount with a limit and a time limit are given with the time limit able to be increased until one country revokes the agreement. Merchant Republics can create trade leagues to increase profit or defense. New espionage and counter espionage actions have been added, and nations are able to share or steal maps from each other. A new feature allows you to watch the map and see how it evolved throughout the time you have been playing. While it does add some nice new options, it doesn't add as much as some of the past expansions making the price seem a little high by comparison.