Dr. Annie Gray

They said that the more they played it, the more they liked it.

and that they would take it up.

But first, the cast is trimmed to six, and the weapons updated.

There are now 324 possible solutions, but there's something the company just doesn't like.

My dad, he called it, not very imaginatively, murder with two exclamation marks.

I suppose they felt Cluedo would be a much catchier title.

It's a combination of Clue, which of course is what the game's about, and Ludo from the Latin I play.

My dad, he admitted it changed for the better.

The war, and a shortage of materials, delay the game's launch.

And it's not until December 1949 that it appears on the shelves.

It was produced in quite a small black and white, but not ostentatious or eye-catching box.

But if Anthony's motive was money, the murder game doesn't quite make him a killing.

In 1953, the Waddingtons offered my dad £5,000 for the overseas rights to the sales.

They had told him that they were very disappointed in the sales figures overseas, particularly America.

Now, in 1953, £5,000 would have bought two respectable houses and a car.

So he probably thought it was the responsible thing to do.

But he had no way of knowing just what a phenomenon it would become.

And it was that 1960s version, coloured red, with a figure of Sherlock Holmes on the front, which really increased the sales dramatically.

Since its launch, more than 150 million copies have been sold around the world, including in the US, where it's known as Clue.

Why is it so popular?