EU4 Combat Simulator

  • Combat simulator for Europa Universalis IV by Paradox Interactive
  • Version 1.3 (alpha), reflects the state of the game at Patch 1.18.

  • Only sporadically maintained at the moment due to other projects, feel free to fork/do merge requests/use the code base in any way you wish.

Update (11/02/2017): Downloads are once again enabled. Simulation is still reflects Patch 1.18. Some combat logic bugs have been fixed, others surely remain. Major change is that now you can go step-by-step through a battle. However, there are many things that could be done UI-wise that I have no time to fix myself (make die rolls configurable, allow selection of individual units and display detailed stats, etc.

How do I get it?

  • Go to Downloads (in the sidebar) and get the correct jar for your platform; the 32bit/64bit distinction pertains to your JVM, not your OS. The download counter does not represent the actual traffic, since it is reset on each new build which triggers redeployment of jars to the Downloads folder. The service, where it was previously hosted, was discontinued.
  • Alternative: manually build it with maven, for example mvn package -P windows64
  • IMPORTANT note for Mac users: macos swt jars need to be manually started with the -XstartOnFirstThread command line option, e.g.: "java -XstartOnFirstThread -jar eu4-combatsimulator-1.2-mac64.jar"

Resources used for combat logic modeling

  1. EU4 Wiki: Land warfare (main resource)
  2. EU4 Wiki: Land units
  3. EU4 Wiki: Military technology
  4. EU4 Wiki: Technology groups
  5. Knowledge of contributors, discussions under Issues

How to contribute

Don't be afraid to hop in and contribute - everyone can help:

  • Contribute code via git
  • Source code is Java, with Lombok annotation features (see
  • Ideas for new features
  • Report bugs
  • Point out wrongly modeled combat logic
  • Code review