Georg Leopold von Reisswitz was not your typical wargamer.
He never applied paint to an orc or a space marine. He never spent pizza-fuelled weekends conquering distant parts of the universe. Nor did he ever step foot inside Games Workshop. But he laid the groundwork for all these pastimes, because he designed one of the first wargames in history, if not the first.
And he wasn't doing it because he wanted to escape from reality, or prove that he was a military genius despite never having been anywhere near a serviceable firearm. He knew how to fight, and how to lead men in battle. He was a Prussian officer who fought in the Napoleonic Wars of the early 19th century.
(Anyone who doesn't know where or what Prussia was is in sore need of a history lesson. It was in eastern Germany, had Berlin as its capital, and held a lot of very bad farming country in what is now Poland. Their aristocracy, known as 'Junkers', lived in constant fear of a peasant uprising and developed their military to a frightening degree in order to defend themselves against it. That military made them big players in 19th century Europe - and eventually the core of the German state that Bismarck created. The downside is that the military culture became way too important, helping set the stage for all the horrible things that happened in the 20th century. But I digress...)
Kriegsspiel - literally 'wargame' - was intended not as a harmless diversion but as a tool to train officers. In peacetime, it's really rather difficult to give officers a way to learn how battles actually work, because it's hard to simulate the chaos and unpredictability of combat.
Firstly, Reisswitz designed maps without hexes or squares, so that units could move much as they would in real life. This was no stylised game like chess: if you order a unit of dragoons to advance 50 paces NNE, then that's what they'll do.
Secondly, Reisswitz removed the random element. Kriegsspiel does not use dice. Instead, there is an umpire who is independent from the players and adjudicates the results, with the aid of various tables provided with the rules.
Thirdly - and here's where it gets really interesting - there isn't a single board. There are at least three.
Each player gets their own map/board, on which they have to keep track of troop movements themselves. The umpire holds the correct, accurate board - and only tells the players of troop movements they would be aware of if they were a commander in the field. They have to figure out how to interpret reports from their subordinates. If they want to find out more, they have to send out scouts - but if a scout is captured by the enemy, the players may never know what's over the next hill until it's too late. This restriction of perspective is really the most important aspect when it comes to training: the players have to learn how to deal with the limitations that a commander would face in reality.
By a combination of good networking and even better luck, Reisswitz managed to get the game in front of the Prussian king, who played it along with some of his generals. They spotted the potential straight away. You'd think Reisswitz would be made for life - but while he may have been entirely unlike most wargamers, he did live up to the stereotype in one way. His social skills were... not that great. Which meant there was one aspect of military prowess he couldn't train for with Kriegsspiel. The one most important to a peacetime staff officer: politics.
Jealousy and resistance within the army meant that Kriegsspiel was not used as much as it could have been, and Reisswitz eventually committed suicide in despair. His son picked up where he left off, and kept it alive until it was discovered by Bismarck-era strategists, before eventually being forgotten until the 1980s. While it can't compare in popularity to anything from Games Workshop, it enjoys a keen fanbase, and can be bought from a company with an amusing name.
For more information, check out kriegsspiel.org.uk.
(Note: there are other games with similar names, but they aren't Kriegsspiel. If in doubt, remember that Kriegssiel has two s's)
(and if anyone ever finds or makes an online version, let me know. Also if Sid Meier ever updates Gettysburg!, which I've just realised was a pretty good RTS implementation of many of the basic ideas)
(later note: never mind. Empire: Total War covers the general tactical game just as well - though it fails utterly in representing the restriction of information a commander of the day would have faced)