If I was to ask you to think of a timeless computer game, what immediately springs to mind? Perhaps the ultra-violent Doom, or Age of Empires, or even Tomb Raider?

How about Microsoft Solitaire?

Solitaire - the preserve of procrastinating office workers and bored housewives - is celebrating its 25th anniversary, and Microsoft is commemorating it by bringing an updated version of the game to Windows 10, and a no-holds-barred group tournament.

It's an iconic game; one that's shipped on hundreds of millions of computers, with billions of games played. But why has Solitaire been so successful, and how did it start out?

The History Of Solitaire

Cast your mind back to 1989.

Microsoft was about to release Windows 3.0; this was a radical (for the time) change in the way operating systems were designed, with a richer, more colorful graphical interface, and a reduced emphasis on the MSDOS prompt.

It was released during a time when few had a computer in their home, and the idea of using a computer through a graphical interface was novel and dangerous.

3.0 would be an phenomenal success for Microsoft, and cement their position as market leader, but it had to overcome one major hurdle first.

At the time, relatively few people knew how to use a keyboard and mouse in tandem, within the context of a graphically oriented computer system. Things now taken for granted, like dragging and dropping a file, were alien for many.

So, Microsoft, with the help of an intern called Wes Cherry, developed a basic card game that would ship with every copy of Windows 3.0, and every copy of Windows to ship since (minus Windows 8).

That game was Solitaire, and ostensibly it was to train office workers how to cope with the shape of computers to come. But in reality, rather than being a training tool, it became the ultimate tool for procrastination and time wasting, and one that will once again ship with the latest version of Windows - Windows 10.

The version of Solitaire that shipped with Windows 7 was controversial, with some choosing to port over the older version from Windows XP rather than use the newer one.

The Rules

Solitaire is a paradox. Firstly, the card game itself isn't called Solitaire; it's called Klondike, and is one of the many card games in the Soltaire family. It's also deceptively hard, despite being ostensibly simple to play.

A standard 54 card deck is shuffled, and the two jokers are removed, leaving 52 cards remaining. 28 cards are then removed, which are then divided into seven piles of cards. The first pile will have one card, the second pile will have two cards, and so on, until the seventh pile has seven cards.

There are then four "foundations" above the piles of cards. These allow the player to store stacks of cards that are of the same suit, thus making it possible to complete the end-goal, which is to build a stack of cards that ranges from 2 to king.

As the name suggests, Klondike Solitaire is played with only one player. But with over 7,000 trillion possible hands, it can certainly offer enough variety to keep you guessing. Not every hand dealt is winnable, and it's possible to make a mistake at any point that can transform a game from theoretically winnable, to impossible to win.

The simplicity of its rules, and the fact that no two games are the same, has lead to it being enduringly popular, and now this iconic game has reached a major milestone.

Solitaire at 25

Microsoft, not one to shy away from a grandiose celebration, is commemorating this particular anniversary in style.

Firstly, they've announced that Solitaire will be returning to Windows 10 as part of their default install. Solitaire has, of course, been a part of every Windows, with the exception of Windows 8 as a downloadable extra. Also joining Solitaire as part of Windows 10's default games collection is Candy Crush Saga.

They're also going to challenge your Solitaire skills, in a card-game battle royale, taking place in June.

In the run-up to the public tournament in June, Microsoft has been hosting an internal Solitaire contest among its employees. That competition has been taking place over the past few days, and the same challenges the Microsoft staff have faced will be put to the public in June.

Microsoft have been pretty hush on the specifics, and as Peter Bright writing for Ars Technica put it, it's not obvious how they'd be able to turn a single-player, randomized game where only 80% of all games are theoretically winnable into a competitive tournament.