Hearts of Iron IV (2016)

A front can fail because the equipment, railway supply or production plan behind it is wrong. Learning to diagnose one such failure makes the industrial scale of the Second World War tangible. Begin with the tutorial and base game, concentrating on a limited theatre before adding specialised expansion systems. Diplomacy is heavily shaped by the coming war, so choose this for mobilisation and logistics rather than free-form peacetime statecraft. Expect several evenings of learning before the plans feel reliable.