Games: Learning at a snail's pace why it is that children get so lucky

Never play a child at a game where chance plays a part, says William Hartston. They are just too lucky.

I first discovered the Principle of Infantile Aleatoric Advantage when playing Snails with Nicholas, aged five. The rules are simple: you go into the garden and select two snails (or more if you wish to play with more than two players) which are then placed on the outermost wooden slat of the garden table. Each player in turn then rolls a die. If a "1" shows, the player may move his snail one slat forwards. If any other number is rolled, the snail stays where it is. (On a particularly lazy afternoon, one may play with two dice, only moving the snail when a double-one is rolled.) The first snail to reach the centre of the table wins.

Now our garden table has eight steps before you reach the centre and Nicholas's snail was up to the seventh before mine even started. By that time I did throw a "1", the snail had exuded so much slime that it was quite a feat to unstick it from the table and slide it a square forwards. Then my young opponent threw another "1" and the game was over.

In the next game he beat me 8-1. I scored a thrilling win, by 8-7, in game three, but his 8-3 win in game four made a total score of 31-12, far above anything predicted by the laws of probability.

It's not just with snails. He regularly beats me at any card game of pure chance too. I suspect this is why they ban children from casinos. It's not because they are considered too young to fritter their money away. It's just that they are so lucky.

Last Saturday we played Monopoly which I know is predominantly a game of skill. I did everything right: I bought up the light blue set and the Marlborough Street set. Meanwhile, Nicholas was single-mindedly buying up and developing the green set. Ridiculous! Nobody ever wins with the green set. Unless, of course, the principle of Infantile Aleatoric Advantage comes into operation, guiding the five-year-old unfailingly to all the Chance and Community Chest cards that offer financial reward, while dumping all the "Income Tax Pay pounds 100" type of penalties on the hapless opponent. A copy of Billionaire had arrived the previous day from Spear's Games. It's a sort of dysfunctional Happy Families, with players trading cards in an attempt to get a full set of commodities while avoiding the penalty card. There are eight cards representing Oil, Gold, Shipping, Diamonds, Property, the Movies, Media and Computing. You use as many sets as there are players (from 3 to 8), deal the cards, they offer swaps of number cards of the same type - only it's all done face down, so you never know what you're getting.

Far too complex for a five-year-old who struggles to hold a hand of eight cards. So when Nicholas, his brother James and I began the first hand, I was quite confident. Until Nicholas shouted "Billionaire." He had eight Diamonds. It's no good. I'm going toteach him chess.

Billionaire, from Spear's Games, retails at around pounds 10.