The Cossacks is the seventh expansion for Europa Universalis IV. It was announced on 2015-10-15. It was released on 2015-12-01. The expansion coincided with Patch 1.14. The Cossacks was widely criticized by many for being highly unstable, having a high price, and not offering much content, and led to EU4: The Cossacks being called "the worst DLC of the year" by IGN.
- New diplomatic options: let the world know what you think of your neighbours by setting a public attitude to foreign powers.
- Tell the world what you want: designate neighbouring provinces as "places of interest", build trust with other nations, and entice allies with the promise of land for their support.
- Tengri: Tengrism is now a syncretic faith, allowing it to tolerate certain secondary religions as if it were a national faith.
- Horde unity and razing: nomadic nations now must pay attention to the horde unity of their tribes – a unity that can only be maintained by the occasional pillaging.
- Improved culture changes: you can now restore a previous culture to a converted province, or convert a province you hold to a culture that is not your own.
- Native policies: set your policy for colonial encounters with natives. Are you focused on quick subjugation, peaceful growth or trading advantages?
- Improved espionage: new spy actions allow you to study the technology of more advanced countries and prod your rivals' subjects towards independence.
- New diplomatic feedback: select provinces of interest, manage opinions, and a new trust and favors mechanic.
- An internal politics system called Estates which brings more risk and reward to country management
- Revanchism: a ability allowing a nation to survive a loss and live to fight another day
- A random New World update: requires the Conquest of Paradise bonus DLC exclusive pack
- Updated nation designer
- Victory cards: another way to gain score in a game
- New areas and regions which give a better naming scheme for conquered lands
- A Leaderboard which records the highest top of the Ironman scores of players from around the world. Must be logged into the Paradox account to use this feature, tough.
- New colonial trade goods system that shows player chances of discovering specific goods in uncolonized provinces.
- Cultural unions: They have been top highly refixed and worked.
A list of the developer diaries for The Cossacks can be found here.