Paradox Interactive has revealed a new Theater Pack for Hearts of Iron IV, Thunder At Our Gates, which is bringing new focus trees for three nations and additional game features. At the same time, a free update is coming for all players.
Hearts of Iron IV: Thunder At Our Gates adds new focus trees for Australia, Siam, and the Dutch East Indies.
The new Australian focus tree focuses on balancing the needs of Australia after the Great Depression with British demands. Players will influence elections, develop natural resources, and explore alternate histories of either a nationalist or communist Australia.
The Siamese focus tree puts players in charge of deciding either a civilian-led constitutional government or a military coup — or a balance between the two. Players will industrialize Siam while navigating international political spaces, resisting imperial powers or submitting to them. Alternatively, players can conquer the surrounding nations to follow the path of the old Rattanakosin Kingdom.
The Dutch East Indian focus tree follows the nation during wartime with its highly valuable rubber and oil reserves. Players will choose between rebelling against or staying loyal to the Netherlands, and a special military focus tree is focused on an operation with Duch and East Indian forces.
When it comes to new content in general, players can now manage Ship Captains, Generals, and new Raids.
The release of the Hearts of Iron IV: Thunder At Our Gates theater pack will come alongside a free update that includes a few game changes. Details on these haven’t been fully explained, though there will be a Regimental Support feature that includes new ways to put support units with your military divisions.
A trailer for the Thunder At Our Gates theater pack can be watched below:
The Thunder At Our Gates theater pack for Hearts of Iron IV is set to release on June 11, 2026, on PC. Players can check out some screenshots of the new content below:
