Over the past several decades, most regional and local conflicts have merely been the scenarios prepared in advance in the "kitchens" of great powers. The aforesaid scenarios are practically tested on simulation-based models that are formed as war games, which considerably save resources and improve the strategic and operational-tactical planning process. Information technology has had the decisive impact on the development of war games resulting in the fact that various software packages have been developed, as well as the systems which provide support to commands and HQs in a decision-making process at all command and control levels. The findings showing that resources can be rationally exploited and financial funds considerably saved indicate the efficiency of applying war games in the operational planning process and cause specific simulation-based models to be developed in commands and HQs of modern armed forces. The aim of this paper is to point out the role and importance of war games in the operational planning process. To that end, various models of war games have been analyzed, along with the possibility of applying them in the operational planning process and activities conducted by the commands and HQs of the Serbian Armed Forces. The paper examines the disadvantages of models that have already been applied in the drill of the Serbian Armed Forces units, at the same time indicating the modern models of war games. The topic has been addressed through four items: 1) the term and characteristics of war games; 2) the elements of war games; 3) the structure of war games and 4) the application of war games in the operational planning process. It has been concluded by the research results that war games are an integral and inseparable part of the operational planning process in modern armed forces and that they are implemented as various models for making decisions during the preparation and execution of combat actions and armed conflicts. The collected findings have shown that war games are an integral part of the operational planning process in the Serbian Armed Forces too, as well as that the level they have reached is not satisfactory and should be improved by being more comprehensively implemented in commands and HQs, provided that automated command-information systems have previously been established. Ensuring that the above-mentioned conditions are met at all command and control levels would contribute to introducing a decision-making support system in an organized manner and improving the efficiency of the operational planning process, and thus making timely decisions while conducting missions and tasks of the Serbian Armed Forces.