I went to the Museum twice. The first time I got the times mixed up and after getting about half way through the 3rd floor heard the announcement that the museum was closing in five minutes. There were some great exhibits on the Thirty Years War and the Great Northern War. I'll need to go back to this section.
I went back a couple of days later and this time went right to the Wargame exhibit that was on. This was an excellent exhibit which did a great job of explaining the history of wargaming and then relating it to use by the military and then showing how the hobby developed and the different types of games that reflect military histories of battles and the adventures of men during wartime.
So there it is. There were many other games from Chess to War Hammer. You can check out the facebook pages for the exhibit and the museum. If your visiting Stockholm I would highly recommend going to the museum.
https://www.facebook.com/armemuseum/
https://www.facebook.com/krigsspel/