Armored Core: Project Phantasma is a standalone expansion to the original Armored Core, released for the PlayStation in 1997. It focuses on arena-based combat, introducing ranked one-on-one battles against rival pilots Players customise a humanoid mech using interchangeable parts that affect mobility, firepower, and energy use. The game places less emphasis on mission variety and more on mechanical optimisation and combat skill. Its structure and mechanics helped define competitive elements that became central to later entries in the series.