Gaming
The Prussians started to apply gaming situations to military training during the 1800s. The games consisted of detailed maps and different colored blocks to represent troops. After the games, the players' decisions on troop placement and appropriate armaments were discussed and critiqued.
A good present day example is Madden NFL football. Unlike basketball or baseball, where you may play hundreds of games a year, in football you normally only play a few handfuls. But with a game like Madden NFL football, gamers can play thousands of simulated games, which allows them to read defenses, see routes, and learn various formations and terminology. And most players and coaches agree that this gives the players a huge learning advantage.
Game theory is mathematical method of decision-making in which a competitive situation is analyzed to determine the optimal course of action for an interested party, often used in political, economic, and military planning.