Panels and their modules, such as for walls and roofs, are disclosed that provide armored shelter for protecting people and equipment from ballistic projectiles and mortar attacks. Each module is made from multiple co-parallel plates arranged in a stack, spaced apart, and held together along their sides by side elements. This is done in such a way that, when assembled side-by-side or end-to-end into panels, adjacent modules overlap one another to prevent straight-through seams yet allow any damaged module to be removed and replaced without moving adjacent modules. Space within a module, between plates and sides, can contain energy absorbing material in a variety of shapes. Plates serve as structural flanges, and side elements comprise structural webs, to permit each module to function as a structural beam.