With every year, a new installment in the long running Call of Duty franchise is now a guarantee. Since the series began in 2003, the immensely popular first person shooter has not missed a major annual release a single year, even to this day. Many of these games have been huge successes, from Call of Duty 4: Modern Warfare revolutionizing multiplayer shooters, to Call of Duty: Black Ops breaking new ground is first person storytelling.

Additionally, considering the nature of these games, the many battles the Call of Duty series has placed players smack dab in the middle of has varied with each release. From multiple entries in World War 2, to the Vietnam war, all the way to many years in the future, Call of Duty seems to have tackled just about every variation and era of combat. However, even with the numerous entries already available for players, there do remain a handful of possibilities for locations and timelines that the developers can dive into for subject matter.

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Call of Duty: Advanced Warfare features a fictional depiction of a second Korean War; the United States and South Korea against North Korea. These battles contain many futuristic weapons, hardware, and other wild advanced military technology living up to the subtitle of the game. As bombastic as that was, an account of the real Korean War is still untapped territory for the Call of Duty franchise in terms of narrative and setting.

The Korean War, much like other real life events featured in Call of Duty, was a horrible time in history. Spanning three years, the conflict pit the United States, China, and both the North and South parts of Korea into a deadly battle. In the end, nearly five million lives were lost from all the fighting, marking the war as one of the most tragic moments in human history.

The bleak and violent tone of this conflict may be heavy subject matter, but if handled with enough grace and respect, a Call of Duty game could pull it off as a compelling look at the past. Infinity Ward did deliver a viscerally disturbing take on war with 2019's Modern Warfare, so something like this would play out similarly in execution.

A notable war for barely lasting a month (January-February 1991), the Gulf War was a brief but brutal struggle between the United States and other allies against Iraq. The invasion of Kuwait was the most pivotal moment in this conflict, which would serve as the largest portion of the storyline if a new Call of Duty game would center its story around this war. The Gulf War was also notable for being the introduction of actual live news broadcasts directly from the front lines of the battlefield. This could open doors for new methods to depict the violence stylistically, in the form of news reports and possible found footage gameplay sequences.

Considering that historically, much of the events that occur in the Gulf War are connected to the Cold War between the U.S. and Iraq, this would be a good follow-up to Call of Duty Black Ops: Cold War. Since that game and the one preceding it, Call of Duty: Modern Warfare, had some shocking connections to each other. Intersecting the Gulf War storyline into an overall narrative arc could help tie everything together for fans.  

World War Two was at one point, the basis for nearly every first person shooter on the market. It was hot subject matter to be used for setting and gameplay, and considering it was a global war spanning multiple years, its understandable why. However, the conflict preceding this one, World War One, hasn't been interpreted nearly as often in video game form. The most notable recent example would be EA's Battlefield 1, which offered a gritty, brutal vision of the horrors of this major worldwide battle.

Call of Duty has yet to tackle this time frame outside of a flashback sequence during the campaign for Call of Duty: Black Ops 2. The franchise hasn't been afraid to depict the uglier, more grungy side of what war can be. World War One was predominantly fought inside trenches, making for some horrific, closer quarters encounters. The advancements in next-gen consoles in terms of graphics and functionality could also make this the most immersive Call of Duty yet.

Granted, the Call of Duty series has already dabbled in concepts of future war and sci-fi elements with 2014's Advanced Warfare and 2016's Infinite Warfare. However, there were still aspects to the designs and weaponry that had a grounded, realistic feeling to them. Much of what is seen appeared to be technology that could actually exist someday, but this can be pushed even further in an upcoming game.

Swap bullets for lasers and jetpacks for teleporters, and you have a truly sci-fi based Call of Duty experience. The closest comparison to what this title could be is to look at EA's recent Star Wars titles. The blistering pace of space dogfights in Star Wars: Squadrons and on-foot action in Star Wars: Battlefront 2 can be representative of what the all out warfare in Call of Duty would be like. This would also open the door to even more multiplayer options, with the potential for battles that can begin on the ground and then seamlessly soar into the skies above.

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