AAA Games (pronounced “triple A games”) are video games most distinguished by their massive development and marketing budgets. They are meant to be a game development company’s best work and provide a high quality video game experience--comparable to a summer blockbuster. Aside from budget, there are a number of other common features that these games posses. Though there is no limit on genre, unifying qualities among these games are typically photorealistic graphics, game worlds of massive scale, cross-platform releases, and violent content. There are certain exemptions for each of these qualities, but on the whole, these trends hold. However; money is by far the most important factor in determining whether a game is AAA or not, and equally important to these games’ massive budgets is their massive expected revenue and profit. Today, AAA games are expected to sell over 1 million copies, and often provide a multiple-of-cost return on investment for publishers.  AAA games are often the most culturally relevant video games because of their massive marketing campaigns--with titles such as the Call of Duty and Pokemon series becoming household names.
As with the video game industry as a whole, the term AAA is relatively new. After the North American video game crash of 1983, game companies felt pressure to create a standard term to distinguish high quality games from poor quality games. AAA is derived from the US system of grading where A is the highest possible mark. Each A has a different meaning: the first A denotes “critical success”, the second A marks “innovative gameplay”, and the third is meant to signify commercial success . This notation was first adopted by game development companies at gaming expos, such as the Electronic Entertainment Expo or the Game Developers Conference, to mark video games that were of high quality. Nintendo’s “Nintendo Seal of Quality”, used to mark games that had been properly tested and approved, is often credited as the inspiration for this system .
However, the merit behind each of the A’s in AAA have come to mean less and less as the notion of a AAA game has gravitated towards simply being a game that is produced and developed with a massive budget. Titles nowadays are often considered “AAA” before they are even released, simply because of the amount money involved in production, and also because of the precedent set by earlier titles  (e.g. the Call of Duty series). This happens most frequently with companies or franchises that have established reputations, because players expect similar high quality experiences before actually even playing the game. If a game generates an extraordinary amount of revenue, it is typically considered to be a AAA title.
Massive marketing and development budget
This is above and and beyond the most important feature for AAA titles. The recent Grand Theft Auto V received almost equal budgets for development and advertising: roughly $125 million each . To date, this game has sold 32.5 million copies (at $60 apiece), generating massive profits for developer Rockstar Games, and is now the 8th best selling video game of all time . Some titles may even receive more money for their marketing than their development. For example, Call of Duty: Modern Warfare 2’s marketing budget was three times that of its development budget! (150 million and 50 million, respectively). However, this game has grossed over $780 million dollars and is in the top 20 highest grossing games of all time . Yet, massive revenue is not necessarily a feature of AAA titles because there are instances of these games being financial failures. The most recent example is Tomb Raider (2013), which had a total budget of over $100 million, but was considered a failure because it only sold 3.6 million copies in the first month--500,000 short of production company Square Enix’s goals .
Cross Platform Releases
This quality of AAA games is inherently tied to the common theme of big budget and big revenue. Simply put, AAA developers have a strong financial incentive to develop for all major platforms in order to increase their potential audience. This usually entails releases on all main consoles (though this has been less true in the current switch between console generations) and PC/OSx (these are usually secondary to consoles). If a triple A title is released as a console exclusive, the console maker will often pay for this exclusivity to offset the potential lost profit to the developer.  Examples of this are the Gears of War series for Xbox, or the Killzone series for Playstation.
Game-worlds of massive scale and photo-realistic graphics
Again, this quality is tied to the big budget that AAA games receive. However, photorealistic graphics and massive game worlds can often be the cause of this large budget. The video game arms race to develop more and more realistic graphics is a big reason why AAA titles have such high development budgets. Infinity Ward’s executive producer Mark Rubin (responsible for half of the Call of Duty series) even commented that this ballooning cost is “kind of a bummer” . These titles now frequently tout the spectacle and technological feat of having such realistic graphics as major selling points for triple A games. The race to create the best graphics is seen especially in AAA shooters, sports, and RPG games.
There is no clear explanation as to why AAA titles are usually violent, but it is undeniably the case. Most speculation concludes that it is because violence is universally understood and generally provokes adrenaline--two features that developers often strive to include in a quality game . Notable examples of AAA games without violence are most sport games, music games, and some Nintendo titles.
Small amounts of innovation
The massive amount of money pumped into these games often makes developers relatively cautious in the changes they make to conventional mechanics. There is a financial incentive to stick with a tried and true formula, so AAA titles rarely push genre boundaries. Instead, it is common to see games with small changes made across iterations, such as in the FIFA or Call of Duty series. AAA games are rarely the source of major innovation, but instead strive to offer the most refined experience possible in a genre. 
Genres and examples
From the Action RPG page: “Action RPG or Action role-playing games are a sub-genre of role-playing video games that incorporate elements from the action-adventure genre into their gameplay. They "eschew menu-based play for more direct input from the player" emphasizing more real time consequences for each maneuver, unlike turn-based RPG. They key to their development is adding depth without sacrificing the action. As such repetition is often a problem with this genre.”
From the First-Person Shooter page: "The First-Person Shooter (FPS) is a genre of video game defined by a first-person perspective and the use of guns, tools and other projectile-firing items to interact with the world. The genre is made up of many sub-genres, many of which feature adversarial themes. The first-person perspective gives the player the same field of vision and line of sight as his/her controlled character. Because of the first-person perspective, First-Person Shooters have been naturally suited for the use 3D graphics. In addition, their perspective lends well to senses of immersion due to the similarity in experience between the player and the character. Many First-Person Shooters feature multiplayer game modes in both co-operative and adversarial forms. In recent years, FPS games have enjoyed substantial commercial success alongside critical acclaim and positive community reception."
From the Sports Games page: "Sports games are a genre of video games based on popular sports and sports leagues throughout the world. Most frequently, the gameplay is designed to simulate playing the sport; however, there may be many other aspects to the later versions of these games, such as owner/managerial roles, specific player customization and development, mini-games, etc. Additionally, these games are sometimes designed around fictional sports."
From the MMORPG page: "A MMORPG (massively multiplayer online role playing game) is a game in which players from all over the world take control of unique (often self-designed) avatars in an online gameworld. Games in this genre frequently take place in fantasy or sci-fi settings much like other Action/Adventure games. MMORPGs, like other role-playing games, are what Simon Egenfeldt Nielsen et al. might call "process-oriented games:" instead of giving the player one, ultimate objective, the game offers a system with which the player can endlessly interact.  For example, in World of Warcraft, a player may complete a quest-line in an area in the game, but might continue to slay monsters for the sake of leveling up or saving up for a new item. In MMORPGs, then, there is no ultimate goal beyond what the player prescribes for him or herself."
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