As we now know it, war gaming started in Germany about 165 years ago, where the term Kreigspiel was applied to a game played on a map rather than on a chessboard. Here at the Naval War College, war games have been played for just over a hundred years.
"What Is a War Game?,"
Naval War College Review: Vol. 42:
4, Article 6.
Available at: https://digital-commons.usnwc.edu/nwc-review/vol42/iss4/6