A few minutes of downtime is all you need to wage a furiously scribbled war, battling friends or an evil artificial intelligence who knows exactly how to defeat you. The battlefield is a wartorn, crumpled sheet of notebook paper. Half belongs to you, half to your opponent. Build your forts, then brace for combat as you cross sharpened pencils, taking turns lobbing handdrawn bombs until their forts are mere scorched smudges. Victory belongs to the sketchiest player!
It's all-out warfare. On paper, of course!