Factories gain efficiency the longer they produce the same equipment. Retooling to a new tank model causes a temporary "efficiency cap" drop.

Victory in HoI4 is often decided in the factories years before the first shot is fired.

Writing a "long paper" or guide on requires breaking down its massive mechanical complexity into digestible pillars. Whether you are preparing a master's thesis on the game's systems or a comprehensive strategy guide for a community, the structure below covers the essential "heats" or core mechanics that drive the game. 🏛️ Pillar I: Political Foundation & Economy

Build Civilian Factories (CIVs) first to increase your future building speed, then transition to Military Factories (MILs) as world tension rises.