“Back in the day” I admit I was one of those D&D geeks. This was back when you could play with just a coupe of books, a handful of dice and your imagination.
I always thought that gaming was an excellent “tactical thought” exercise when approached in the right manner. The USMC Marine Corps Gazette has had a tactical scenario game section going for years and USMC leaders use them to train junior officers . Even though the whole “Sword and Sorcery” aspect of D&D removes much of the “realism” of modern tactical decision making, the core trait of organizing and utilizing equipment and personnel remains intact.
If you are an old time gamer you will love these comics. They are called The Order of the Stick. Take a look at their site. Those “in the know” will find them hilarious.