Lego
The Lego brick presents a fascinating paradox in matters of stealth. By day, these colourful constructions sit innocently upon shelves and floors, their presence entirely unremarkable. Yet in the darkness of night, the singular Lego brick transforms into perhaps the most devastating anti-personnel device ever accidentally deployed in domestic settings.
The brick's 0.016 square-inch surface area delivers approximately 3.4 million pascals of pressure to the human foot—a surprise attack that has brought grown adults to their knees with the efficiency of any shadow warrior. The element of surprise is absolute; no victim ever expects the brick beneath their heel.
Ninja
The ninja's mastery of onshinjutsu—the art of invisibility—represents centuries of refined technique. Historical records suggest that Iga and Koga clan operatives could infiltrate fortified castles, traverse guarded corridors, and complete their missions without detection in an era before motion sensors or CCTV.
Their arsenal of stealth technology included ashiaro (wooden foot attachments leaving misleading tracks), specialised climbing tools, and an intimate knowledge of human perception's limitations. The ninja understood that true invisibility was not about being unseen, but about being unremarkable—a psychological insight that predates modern camouflage theory by four centuries.