The Manifesto of the Anti-Prank, also known as Meta-prank
The client lays down on the table and it's ready to get his massage with hammer and stick (as in Tok Sem or Seitai). The masseur, instead of returning with wooden tools, comes with a heavy steel hammer and a pointy steak. The cliente is scared with this something inappropriate and dangerous, but thinks: "He knows what he does". The steel comes hard, puncturing his skin and hurting him a lot. He leaves feeling stupid.
The anti-prank is born on the exact spot where the trust in common patterns is punished by the world it itself has rationalized.
Laughs come from reality - how the instant of realization (it's a prank) doesn't affect the real outcome if not by an action that could be defined as unrational. Anti-prank is a consequence, a late surprise that goes beyond the social contract of humour, which can envolve marks, pain or bruises.
Trust on the rational is a ingenuity trap itself. There is no catharsis, only the fact that we are naive. Reason does not protect from suffering, things remain incoherent. The absurd is constant and needs to be refunded to the popular collective.
As in the modern Milgram Experiment, the subject enters the experiment aware of the big picture and rationalizing it as something controlled. They hear screams as he increases the voltage of the shock delivered to the target. "Torturing people with electricity goes against human rights... therefore, for the experiment to exist, the target must be just an actor and the shocks are a lie." Maximum voltage is reached, then the scream stops, followed by a heavy sound hitting the floor. When leaving the test, the subject sees the target, dead on the ground.
A friend tells he committed homicide and asks you to hide the weapon, speaking in a serious tone that probably could be taken as a joke. Agreed, hide the weapon, assuming it's a prank. A few days later, the police knocks on your door and arrests you.
Or, as in an art gallery, a work can be discreetly inserted from outside: staff will recognize the intervention, while tourists believe is just another work in the collection.
It is discovered too late that there was never any pact to be broken...