A system and method are provided for employing man-portable unitary platform system segments, particularly as components of integrated castle defense systems. A lightweight modular and mobile system of integrated platform segments is provided to facilitate users integrating flexible platform configurations secured to existing wall structures to support myriad user tasks. Individual platform system segments can be autonomously employed, or can be linked together after being quickly attached to a wall, a structure, or another supporting surface by two users in minimal time. In law enforcement, security, military and/or paramilitary employment scenarios, individual platform system segments are emplaced, and linked together, to provide a unitary defensible position in a matter of minutes. An overall platform structure of a plurality of individual man-portable platform system segments provides operational and employment flexibility that was previously unattainable to bolster or boost defenses of a particular position against increasing, and increasingly agile, threats.