The theory that it's possible to avoid being bollocked for misbehaviour if it's so blatant that the teacher will be unable to believe it actually happened, or incapable of responding in a dignified and appropriate manner. For instance, a twenty minute tirade about "stringy chicken dicks" and "this woman, right, gets shagged by a horse" in response to reading Animal Farm (qv) will generally result in a feeble "that's enough now, Paul" Immunity in excess does not extend to those laughing, however, who will be punished with misdirected severity.

This theory was pushed to its very limits when we set fire to a desk and started doing deodourant-flamethrowers in front of a cover teacher in our drama class. Punishment? Not a sausage.

Clint brought a dead dog he found in the road into our form room and proceeded to make the corpse dance on his desk. After taking a moment or two to absorb the true horror of Clint's actions, our form tutor merely asked him to "put that away until break". This suggested that playing with dead animals at school was acceptable provided that it didn't distract us from answering the register.

I was lucky enough to experience immunity in excess one Thursday afternoon, when my P.E. class whiled away the idle hours by ripping down the blinds and using a metal metre ruler to poke holes in the ceiling. Apparently, public schools are made from Plaster of Paris hidden by a thin coat of paint.