With the advent of modern household products and office supplies-binder clips, clothespins, rubber bands, ballpoint pens, paper clips, plastic utensils, and matches and barbeque lighters-troublemakers of all stripes have the components needed to build an impressive, if somewhat miniaturized, arsenal. Toy designer John Austin provides detailed, step-by-step instructions for each project, clear diagrams, and construction tips, for mayhem-loving MacGyvers. The 35 devices include catapults, slingshots, minibombs, and combustion shooters. Build a tiny trebuchet from paper clips and a D-cell battery. Wrap a penny in a string of paper caps to create a surprisingly impressive ''bomb.'' Several of the projects even include variations where combatants mount laser pointer sights to their shooters to increase their accuracy.