On the poker floor of The Hippodrome Casino in London's Leicester Square there are lots and lots of men. There are men in baseball caps, men in sunglasses, men in suits. 

One looks as though he has been sitting in this carpeted, windowless room for 100 years. He's slumped over a poker table, eyes just about open, while a masseuse rubs his shoulders.

'Around 95 per cent of our players are men,' says the casino's director of poker, Kerryjane Craigie. Known by everyone as KJ, Craigie, 54, is the only woman in the country to run a poker floor. Possibly, she thinks, the only woman in Europe.

So why is it such a male world? 'Who knows? I can theorise as much as anyone else,' says TV presenter and professional poker player Victoria Coren-Mitchell, 50. 

'An obsession with numbers and statistics is more traditionally male; there are security issues involved in travelling alone with cash sums and walking around at night; the long hours of a poker tournament are not conducive to family life – but in a way I'm the worst person to ask, because I do play poker and I don't know why more women don't!'

Craigie has other theories: 'A lot of women are interested in poker but feel uncomfortable walking into a room that's predominantly male.' The atmosphere on the floor is intimidating, the banter in particular. 'Boys can be tough to deal with on a table,' she says.

To encourage women to play, Craigie started Ladies Club at the Hippodrome. It's a monthly poker tournament for anyone, of any level and age; some players are in their 20s, some are in their 70s. 

It costs £15 to play and the top three players win cash prizes. There's a league, too, and this year a trip to Las Vegas is the winning prize. Normally, Craigie has around 20 attendees a month, but some evenings there are more than 30. 

Crucially, Ladies Club always takes place in its own room, away from the men. I've never played poker before, but Craigie assures me the ladies night is friendly, so I join for the evening. She wasn't lying. 

When Craigie introduces me as a total beginner, one player called DeAnna – booming voice, rolls cigarettes at the table, tells knock-knock jokes – shouts, 'I love a virgin!' Everyone cackles. The mood at Ladies Club is very different from the floor outside.

I am put on a table with seven women: DeAnna, Olga, Rose, Nilda, Emily*, Kelly and Jane. Bar Olga, who is also new, they all seem to know each other; as we sit down there's lots of chattering and hugging. The only man present is Nick, the curly-moustached card dealer. 

All the women adore him. And, although he does a lot of sighing and eye-rolling, Nick clearly adores Ladies Club, too. He says the usual 'cash players' – people who bet money, not chips – are quiet and serious. But this evening is a racket. 

At one point, after DeAnna has made yet another joke and Nick has made yet another eye-roll, she leans over to him and says: 'You love dealing here really, don't you!' Nick says no, and they all howl.

I sit next to Kelly, who is seriously sunny but also a stone-cold pro. The Hendon Mob, the world's biggest poker player database, ranks Kelly Saxby from New Jersey in the US 45,660th best player in the world. (There are around 758,115 players in The Hendon Mob system, so this means Kelly is in the top six per cent.) 

The Hippodrome night attracts an international clientele: sitting opposite me is Jane, a bespectacled retiree from New York.

Maths and strategy are key in poker, but the most important skill is reading people. In the poker world they call it a 'tell' – the tiny thing that gives away a player's motive. A tell could be how aggressively someone slaps their chips on the table, or the way their nose twitches when they look at their cards. There are reverse tells, too. Emily says she makes her hand quiver. It tricks her opponents into thinking she's nervous.

DeAnna says: 'When Boris Becker played tennis, he stuck his tongue out before he served. And he would hit the ball in the direction of his tongue.' The only player to realise this was his rival, Andre Agassi. 

For years, Becker couldn't understand how Agassi predicted his shots. Once they'd both retired, Agassi explained the secret. 'That,' says DeAnna, 'was Becker's tell.' (DeAnna's tell, if you wondered, is that if her cards are good, her ears turn red. When she plays a big game she wears her hair down.)

The women at Ladies Club often repeat the line: 'There are no friends in poker!' But it doesn't seem that way. When Nilda bets all her chips, Jane wishes her good luck; when Rose goes out, DeAnna seems genuinely sorry; when I win my first hand, the table cheers. 

Halfway through the game we sing happy birthday to Kelly, who is turning 45. Then, after a cigarette break, we sing it again, only this time with a slice of millefeuille that Craigie has ordered from the kitchen. Kelly sweetly offers everyone a bite.

'People talk at the poker table,' says a player called Kylie. 'If you come every month you get these incredible snippets from people's lives: work, health, family, breakups, death.' (This is true; during one hand, I overhear a woman tell her neighbour that she was born missing a kidney.) 

Kylie got into poker when she was 41. She had recently divorced and her husband and daughter had moved abroad. 'I was alone in London, and miserable.' So she started playing poker. 

Within six months she was competing around the world. The game, also 'gave me a social life'. Now she's 52, happy and close to her daughter. 'Poker changed me. I've metamorphosed. I've made friends. I've found myself.'

She adds: 'The thing is, poker and life reflect each other.' When Kylie started playing, she was insecure. 'It was like I was blushing in my personal life and, as a result, I was blushing at the poker table. 

But that changed the more I played. This game taught me to be courageous. You have to bluff in poker – and sometimes you have to bluff in life. You need to tell yourself you're great.'

Near the end of the evening, things become more serious. 'This is 'freeze-out mode',' says Jane. 'You can't buy any more chips, so when you're out, you're out. That's why it got quiet all of a sudden.' 

Olga is the first on our table to go, then Rose, then Jane. I lose next – which puts me in 12th place out of 23. I still don't understand how poker works, but it's the best night out I've had in months.

To find out more, visit the Facebook group Ladies that Poker at the Hippodrome