as the height of a model of a human measured from the base of its feet up to the eyes or top of the head (e.g. 28mm). Military wargames typically aim to model time and space as realistically as is feasible, so everything in the simulation conforms to a single scale. Recreational wargame designers, by contrast, tend to use abstract scaling techniques to make their wargames easier to learn and play. Tabletop miniature wargames, for instance, cannot realistically model the range of modern firearms, because miniature wargaming models are typically built to a scale between 1:64 and 1:120. At those scales, riflemen should be able to shoot each other from several meters away, which is longer than most game tables. If model soldiers could shoot each other from opposite ends of the table, without the need to maneuver, the game would not be much fun. For example, the miniature wargame Bolt Action solves this problem by reducing a rifle's range to 24 inches, a sub-machine gun's range to 12 inches, and a pistol's range to 6 inches. Even if these ranges are not realistic, their proportions make intuitive sense (a rifle's range ought to be longer than a sub-machine gun) and thus preserve some verisimilitude, all the while compressing the battle to fit the confines of the table. Additionally, the ranges are multiples of 6, which makes them easier to remember. Fog of war In real warfare, commanders have incomplete information about their enemy and the battlespace. A wargame that conceals some information from the player is called a closed game. An open wargame has no secret information. Most recreational wargames are open wargames. A closed wargame can simulate the espionage and reconnaissance aspects of war. Military wargames often use referees to manage secret information. The players may be forced to sit in separate rooms, and communicate their orders with the referee in the game room, who in turn reports back only the information he judges the players should know. Some recreational wargames use a referee too, often referring to them as "the GameMaster" (e.g. Warhammer 40,000: Rogue Trader). The fog of war is easy to simulate in a computer wargame, as a virtual environment is free of the physical constraints of a tabletop game. The computer itself can serve as the referee. Types Miniature Miniature wargaming is a form of wargaming where units on the battlefield are represented by