A wargame, generally, is a type of strategy game which realistically simulates warfare. A professional wargame, specifically, is a wargame that is used by military organizations to train officers in tactical and strategic decision-making, to test new tactics and strategies, or to predict trends in future conflicts. This is in contrast to recreational wargames, which are designed for fun and competition.

The exact definition of "wargame" varies from one writer to the next and one organization to the next. To prevent confusion, this section will establish the general definition employed by this article.

Still, some professional wargamers feel that the term "game" trivializes what they see as a serious, professional tool. One of these was Georg von Reisswitz, the creator of Kriegsspiel and the father of professional wargaming, but he stuck with the word "game" because he could not think of a better term. In the US Army, many preferred the term "map maneuvers" (in contrast to "field maneuvers"). At the US Naval War College, some preferred the terms "chart maneuvers" (when simulating campaigns) and "board maneuvers" (when simulating battles), although the term "war game" was never officially proscribed.

Professional wargames tend to have looser rules and simpler models than recreational wargames, with an umpire arbitrating situations based on personal knowledge. If the umpire is highly knowledgeable about warfare (perhaps they are a veteran), then such wargames can achieve a higher degree of realism than wargames with rigid rulesets. In a recreational wargame, such looseness would lead to concerns over fairness, but the point of a professional wargame is education, not competition. Having simple, loose rules also keeps the learning curve small, which is convenient since most officers have little or no wargaming experience.

Likewise, there is less concern regarding "balance" when determining each player's armaments and strategic advantages. In a commercial wargame, the rules are usually designed to ensure that the players' armies are of equal strength to ensure fairness, but professional wargames will tailor each side's capabilities to the scenario to be investigated, and warfare in the real world is rarely fair.

As professional wargames are used to prepare officers for actual warfare, there is naturally a strong emphasis on realism and current events. Historical wargames are wargames set in the distant past, such as World War II or the Napoleonic Wars—simulating these wars realistically may be of interest to historians, but are of little use to the military. Recreational wargames may take some creative liberties with reality, such as simplifying models to make them more enjoyable, or adding fictional armaments and units such as orcs and wizards, making them of little use to officers who must fight in the real world.

Military organizations are typically secretive about their current wargames, and this makes designing a professional wargame a challenge. Secrecy makes it harder to disseminate corrections if the wargame has already been delivered to the clients. Whereas a commercial wargame might have thousands or even millions of players, professional wargames tend to have small player bases, which makes it harder for the designers to acquire feedback. As a consequence, errors in wargame models tend to persist.

Although commercial wargame designers take consumer trends and player feedback into account, their products are usually designed and sold with a take-it-or-leave-it approach. Professional wargames, by contrast, are typically commissioned by the military that plans to use them. If a wargame is commissioned by several clients, then the designer will have to juggle their competing demands. This can lead to great complexity, high development costs, and a compromised product that satisfies nobody.