The art of flipping someone's backpack inside out without them noticing. Nuggeting somebody requires ample stealth because if your victim catches you before their bag is completely nuggeted you must restore their bag to its original un-flipped form. In order to successfully nugget a bag you must empty all contents, turn the bag inside out, put everything back in, and re-zip the bag leaving it, put simply, looking like a nugget. When your victim finally realizes the hilarious fate of his humble nap-sack THAT is the reward in itself.
I'm going to the bathroom DO NOT nugget my bag!