The Call of Duty series has been around for decades and is one of the biggest and most well-known in the games industry. Over the course of the franchise's run, it has managed to redefine what a first-person shooter could be as well as set the standard for what campaigns and multiplayer modes in the genre can offer. As such, Call of Duty titles enjoy a spot amongst the top-selling games every year.

With how long the series has been around for, it is no surprise that it has also changed and adapted a lot over those years. While the series began with multiple entries exploring the famous battles and events of World War 2, it exploded in popularity with the release of Call of Duty 4: Modern Warfare. Call of Duty then found success in more modern titles like the rest of the Modern Warfare series as well as the Cold War-era Black Ops titles. However, for a streak that spanned over half a decade, the series seemed dedicated to releasing titles that were more futuristic.

RELATED: Pro Call of Duty: Warzone Player Gets Pep Talk from Mom in the Middle of the Match

Call of Duty: Black Ops 2 (2012)

The trend was kicked off in earnest by the release of Call of Duty: Black Ops 2 in 2012. While this introduced a lot of new weapons, equipment, and scenery for the title, it also brought innovations to the series like a branching storyline in its single-player campaign. It also gave players the option to customize their loadouts before campaign missions. The game was largely well received, and was praised for its explosive campaign, the scope of its multiplayer mode, and the new ideas presented in its Zombies mode. With Call of Duty 2023 rumored to be futuristic again, and it assumedly being developed by Treyarch, many fans are hoping that it will take notes from Black Ops 2.

Call of Duty: Ghosts (2013)

While 2013's Call of Duty: Ghosts is not as futuristic as other titles in the series, it does take place in 2027 after the Middle East has been decimated by nuclear warfare. The game featured plenty of futuristic technology, a new game mode called Extinction that saw players fending off hoards of aliens, and a mission that saw players shooting in space.

Call of Duty: Ghosts was also the first title developed by Infinity Ward after the studio's acclaimed Modern Warfare trilogy was concluded, although it received a mixed reception. Critics and players largely appreciated the game's willingness to innovate on the series' multiplayer mode, though the game's answer to Zombies was less favorably regarded. Ghosts' campaign also received a mixed response, with many players finding it to be very lacking when compared to Modern Warfare. Still, some have called for Call of Duty: Ghosts to receive a proper sequel.

RELATED: Call of Duty: Vanguard Xbox Beta is Having Issues

Call of Duty: Advanced Warfare (2014)

The first Call of Duty title helmed by Sledgehammer Games was 2014's Call of Duty: Advanced Warfare. The game took the series even further into the future and even introduced exo-suits to the franchise. At release, the game was widely regarded as an improvement over Call of Duty: Ghosts and it found commercial success. However, some players did find the story to be too linear and predictable. Further, the Exo-Zombies mode was lacking a lot of what made Treyarch's Zombies mode so beloved. The game also led to the popular "Press F to pay respects" meme as well as introducing a unique custom scorestreak feature to Call of Duty that has yet to return.

Call of Duty: Black Ops 3 (2015)

The next year brought Treyarch's Call of Duty: Black Ops 3, which continued the series' push to the future and took place in 2065. The game allowed players to tackle its campaign in four-player co-op, which allowed it to feature more open level design and gave players special abilities thanks to cybernetic enhancements. However, one of Black Ops 3's biggest legacies in the Call of Duty franchise is its strong Zombies mode.

Black Ops 3 brought many innovations to Zombies and largely defined how fans think of the mode to this day. The game's Zombies maps and easter eggs set a new standard for the series and developed the mode's overarching storyline in a more considerable way than any titles had prior. Black Ops 3 even received the massive Chronicles DLC that added many Zombies maps from previous Treyarch titles to the game, making it the definitive Zombies title to many.

Call of Duty: Infinite Warfare (2016)

2016's Call of Duty: Infinite Warfare was Infinite Ward's first title under a new three-year development cycle, and was largely the beginning of Call of Duty's move away from futuristic settings. The game's trailer received a largely negative reaction, and quickly became the second-most disliked video on all of YouTube since fans series derided the game's movement mechanics, sci-fi campaign, and futuristic weaponry. The CEO of Activision Eric Hirshberg has since said that Infinite Warfare failed due to not feeling enough like Call of Duty. However, some players and critics had praise for its campaign and Zombies modes, though others found those same modes to be lacking and too predictable.

Call of Duty: Black Ops 4 (2018)

The first Call of Duty game to not include a single-player campaign was Call of Duty: Black Ops 4, which was released in 2018. This led to fans voicing their disappointment leading up to the game's release, although it was received much more positively when it was fully available. The game also introduced Specialists for players to choose from in multiplayer, which determined what special equipment they could use throughout the match.

Call of Duty Black Ops 4's Blackout mode also served as the series' first foray into the battle royale genre. For many, Black Ops 4 was the end of an era for Call of Duty, with 2019's Call of Duty: Modern Warfare ushering in the series' new approach with free seasonal updates and integration with Call of Duty: Warzone. With the rumors that have started circulating about the series' future, however, it will be very interesting to see how Call of Duty's next futuristic setting turns out.

MORE: Call of Duty: Warzone - All the Halloween 2021 Leaks So Far