Compulsory to drink before going on stage to compete in Hot Shot, the actual effects of Cuppliance are not entirely clear. It does seem to affect the judgement of those who take it, making them more vulnerable to badgering by others.
As the name of Cuppliance – a portmanteau of ‘cup’ and ‘compliance’ – implies, it is a vital tool in the maintenance of the status quo in the dystopian future where most episodes of Black Mirror seem to occur, ensuring the vulnerability of the contestants on Hot Shot to the wishes of the judges.