I would suggest there has been quite a significant impact of wargaming on military -operations_. As we Americans are presently finding out to our chagrin, there’s a massive gap between what military intelligence suggests to decision makers and what those decision makers actually do. The same is true with wargames–a couple examples from WW II:

1) German Deputy Chief of Staff General Paulus hosted Barbarossa wargames in late-November, early-December 1940. They demonstrated that the Germans would have to destroy the Red Army west of the Dvina-Dnepr line and make a logistics pause upon reaching that line. The wargames were correct on both points. But on the first the Germans looked at the problem purely from the operational point of view (i.e., addressed only Soviet forces fielded at the time) and ignored the strategic (i.e., the potential levee en masse that the USSR would mobilize). On the second the Germans simply wished away the problem of logistics. Significantly, subsequent German logistical wargames for Barbarossa were conducted AFTER Hitler issued his Directive #21. Bottom line: The Germans went ahead with the operation despite wargame indications of its difficulty.

2) In the spring of 1942 the Japanese Navy conducted wargames covering their anticipated Midway operation. Numerous wargame results pointed to the Japanese getting their butts kicked. Their naval staff therefore kept tweaking the various inputs until they got the desired result. At that point they essentially said, “There, wargames demonstrate the battle is winnable, let’s launch the attack.” Bottom line: The Japanese went ahead with the operation despite wargame indications of its ill-advisability.

I’m sure there are examples of decision makers successfully taking wargame results to heart. Senior leaders know they have staffs to do things like “play” wargames, make recommendations based on those games, etc. But they also feel they get “paid the big bucks” to make the “tough decision” sometimes against the advice of their staffs. They like to emphasize the _artistic_ intuitive/intangible aspects of leadership over the _scientific_ wargame/modeling aspects.