Hearts of Iron 3 is a classic military strategy where players are expected to control countries during the Second World War. Gamers will have the opportunity to choose any of 4 scenarios: Germany in September 1941, the USA in January 1936, Japan in December 1941 and the Soviet Union in June of the same year. Each of them highlights a number of aspects that can be activated or deactivated after launch. At the beginning of the campaign, the player will be presented with a world map, which carefully depicts the territory, including a large number of provinces and even very small towns.

At the beginning of the gameplay of Hearts of Iron 3, you need to start organizing the strategy and secondary tasks. States will begin to interact, and soon an enemy attack will cause the first warnings. One of the initial points is that military messages will be sent in which the high command will address the player as if they were a military leader.

Battles and alerts in Hearts of Steel 3 will be displayed in a pop-up window so you can be informed about different options every minute. They will show the beginning and end of the battle, as well as the leader's decision on many issues. The decision-making system will bring the gamer closer to the executive power of the controlled country. Various military banners will appear on the screen in the form of national flags. The appearance of each of them will be associated with the fact of offering a transaction. Rejecting them will affect relations with these countries.

The economic section will be directly related to production. The creation of human resources will allow the creation of new units, but they will be reduced by various mobilization and other laws. As part of production, you can access the menu for building squadrons, flotillas, installations, divisions and additional brigades. Here you can see the technical characteristics of each unit throughout the game.