Armies fight poorly without bullets and fuel; never outpace your logistical network.
Research takes time, so decide on your primary military focus (e.g., armor, submarines, or fighters) before the war starts.
Manage supply lines that dynamically trace back to your capital, making infrastructure and weather critical strategic factors.
Control everything from division-level unit compositions to precise industrial production lines.
Use the game's AI automation sliders for diplomacy or trade while you learn the combat mechanics.
To get the most out of Hearts of Iron III, playing with its major expansions is highly recommended:
