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They're an institution in the UK. They're in the arcades at every seaside town, and every kid plays them. Now that I have kids I actually think they're brilliant; for £2 each they taught mine everything they need to know about gambling.

- You sometimes win a bit along the way, but eventually you lose everything.

- The jackpot prizes are only there to lure you in, and you never win them. Towards the middle of the shelf are things like £20 notes. We noticed that one of them was getting quite near the edge, and might actually become winnable, but then the following morning its position had been reset to the back of the shelf.

- It's still fun as long as you're just playing with money you don't mind losing, and not expecting to come out ahead.

They even learned something about company scrip, from the tickets that come out of the machines and the ridiculous exchange rate between tickets and the actual rewards at the prize shop.

I asked my son on the way home if he'd put all his Christmas money and savings into the machine if I let him, and the answer was hell no - maybe a pound, but he didn't want to lose all of his money. Valuable lessons all round.