WE went to lunch at Nanny and Granddad’s at the weekend.

After a lovely roast dinner we got out the board games, as we usually do on a rainy Sunday afternoon at their house.

Then suddenly, halfway through a round of Yahtzee, Nanny leaped to her feet. “Damn and blast,” she said. “You’ll know what I’ve forgotten to do.”

Everyone else around the kitchen table obviously did, as no one batted an eyelid at her hasty departure, but I must have looked puzzled.

“I need to breed my dragons,” she shouted over her shoulder as she ran into the lounge and picked up the laptop.

This didn’t really help with my puzzlement.

It turned out that she was only the latest recruit in the family to Facebook game Dragon City. They’ve all been at it, but I had somehow remained oblivious.

The game requires you to build virtual habitats for your dragons, breed them, hatch them, house them and feed them until they’re big enough to battle against other dragons.

“And what do dragons eat?” I asked.

“Apples,” came the response.

Obviously. What else would dragons eat?

And you have to build farms and grow the apples for them to munch on.

It all seems like an awful lot of trouble to go to for virtual mythical creatures.

My son was quickly mesmerised as he watched Nanny care for the dragons – which come in all sorts of different types, from the coral dragon with its colourful reef-like head and body, to the glimmering crystal dragon, to the pirate dragon with its jaunty hat. The poo dragon is less of a looker.

I was bemused. I had a look at it again when I got home, and had to get my ten-year-old to show me the rudiments of the game.

He now has his own starter set of dragons and is waiting for the latest to hatch. This one only takes four hours. Apparently some of them make you wait for days on end for the pitter patter of tiny claws.

I’m still a bit confused. And I have more important things to turn my attention to – like getting past level 181 of Candy Crush.