Uno Reverse — the maths only goes one way

The rule sounds generous: pick how much you drink, then hand out double that number of drinks to the table. The catch is built into the arithmetic. Whatever figure you set for yourself becomes the bill everyone else pays, twice over, so there's no version of this wedge where you come out ahead.

At a real table it splits people into two camps. The cautious ones take the smallest sip they can get away with, then owe just two out. The braver ones down the whole glass for effect, then realise they've now got to find ten drinks' worth of takers round a table that's already eyeing them warily. Either way, the room works out fast that whoever lands this wedge is about to be briefly, deliberately unpopular.

Where it usually snags is the definition of "a drink." A mouthful? A full glass? Settle that before the dart's even in the board, or you'll lose more time arguing units than actually paying out.

It sits in the 1st Circle — one of only ten wedges on that ring, cut wide across the board — so it comes round more often than the rarer stuff further out. Keep your own glass small before your go. It's cheaper insurance than most people work out in time.