As I’ve already mentioned (a few times), Matthew Caffrey’s Toward a History Based Doctrine for Wargaming, sounds terribly dull, but it includes some fascinating anecdotes, like this story from World War II:
The Germans made heavy use of wargaming throughout the war. The Germans’ wargame of the “Middle” Battle of the Ardennes may have been their most unusual. Early in the fall of 1944, the Fifth Panzer Army conducted a wargame of an American attack on their assigned sector — the Ardennes. While the wargame was going on, the Americans actually attacked. Instead of dismissing the game, Field Marshal Walter Model sent only the commanders of units in contact back to their commands. He then directed that actual American movements be fed into the game. The Germans then wargamed each of their orders before executing them. Finally, when it was time to commit the reserves, Model called their commander over to the wargame map, personally briefed him, and sent him on his way.
I love this story:
On the morning of the Iraqi attack [which initiated the First Gulf War], Mark Herman, the designer of the commercial wargame “Gulf Strike” and employee of the defense contractor Booz Allen, was approached by the Joint Staff and asked to produce a wargame of the developing situation. He was on contract by lunch. By modifying his commercial wargame “Gulf Strike,” he was able to begin play of a now classified wargame by midafternoon!