Empire's engine is most closely based on Wizardry Gaiden: Suffering of the Queen and Wizardry Gaiden II: Curse of the Ancient Emperor, but like Wizardry Gaiden III: Scripture of the Dark and Wizardry Gaiden IV: Throb of the Demon's Heart it started incorporating elements of Wizardry VI: Bane of the Cosmic Forge, while retaining the core gameplay derived from Wizardry V: Heart of the Maelstrom. It also adds a significant amount of additions of it's own. Notable changes include: