they wrote orders for their virtual troops on pieces of paper, which they submitted to the umpire. The umpire then moved the pieces across the game map according to how he judged the virtual troops would interpret and carry out their orders. When the troops engaged the enemy on the map, the umpire rolled the dice, computed the effects, and removed defeated units the from map. The umpire also managed secret information so as to simulate the fog of war. The umpire placed pieces on the map only for those units which he judged both sides could see. He kept a mental track of where the hidden units were, and only placed their pieces on the map when he judged they came into view of the enemy. Earlier wargames had fixed victory conditions, such as occupying the enemy's fortress. By contrast, Reisswitz's wargame was open-ended. The umpire decided what the victory conditions were, if there were to be any, and they typically resembled the goals an actual army in battle might aim for. The emphasis was on the experience of decision-making and strategic thinking, not on competition. As Reisswitz himself wrote: "The winning or losing, in the sense of a card or board game, does not come into it." In the English-speaking world, Reisswitz's wargame and its variants are called Kriegsspiel, which is the German word for "wargame". The Prussian king and the General Staff officially endorsed Reisswitz's wargame, and by the end of the decade every German regiment had bought materials for it. This was thus the first wargame to be widely adopted by a military as a serious tool for training and research. Over the years, the Prussians developed new variations of Reisswitz's system to incorporate new technologies and doctrine. Worldwide spread Prussian wargaming attracted little attention outside Prussia until 1870, when Prussia defeated France in the Franco-Prussian War. Many credited Prussia's victory to its wargaming tradition. The Prussian army did not have any significant advantage in weaponry, numbers, or troop training, but it was the only army in the world that practiced wargaming. Civilians and military forces around the world now took a keen interest in the German military wargames, which foreigners referred to as Kriegsspiel (the German word for "wargame"). The first Kriegsspiel manual in English, based on the system of Wilhelm von Tschischwitz, was published in 1872 for the British army and received a royal