The game's userbase maintains a number of communities across the internet, created by Paradox Interactive and by fans themselves
Paradox Interactive has its own official forum. The forum is divided into subforums based on games.
- Paradox Interactive's EU4 forum
- Twitch channel where developers discuss upcoming updates and content
- Youtube channel where developers discuss upcoming updates, content and community members can contribute with spotlights, tutorials or playthroughs
The Leaderboard is an official feature allowing players to upload score results from an Ironman game to the official website. The leaderboard requires that the player be logged in using their Paradox account. It also enables searches by user name and both overall and monthly rankings.
The unofficial community often hosts various events and multiplayer games. Members of /r/ParadoxPlaza (subreddit on reddit) often post content like AARs, bug reports, and strategy guides as a form of entertainment. Paradox Interactive staff also frequent the site on a regular basis.
- Paradox IRC channel at #paradox on irc.rizon.net for discussion of all Paradox games
- /r/Paradoxplaza, one of the largest third-party communities around, located on Reddit. They have approximately 36 100 subscribers as of 25-11-2015.
- /r/eu4, another subreddit dedicated to Europa Universalis IV, which also features content such as AARs, bug reports and strategy guides.
- /r/CrusaderKings/, a third subreddit dedicated to Crusader Kings II, which as well as the other ones features content such as AARs, bug reports and strategy guides.