It's an overused phrase in the world of video game journalism, a tired cliché that very rarely finds itself attached to a title that will actually change anything.
With this in mind, we've searched through the great gaming archives to dig up those titles deserving of wild hyperbole. It probably won't include your favourite-ever title, but it will undoubtedly mention the game that inspired your current evening killer.
These are the 20 games that changed everything.
An archaic marvel by today's highly pixelated standards, Allan Alcorn's tennis simulator was one of the first to populate living rooms and arcades alike. The first 'commercially successful' video game that launched the console industry, you owe it big.
After the initial rush of Pong clones and space shooters, gaming was running out of ideas by the close of the Seventies. Then, Pac-Man arrived, uniting all gamers - male and female - around one arcade cabinet. It's responsible for gobbling more coins than any other arcade game, and is one of the longest running game franchises of all time.
There are earlier 'first person shooter' games, but Battlezone was one of the most fluid examples of the imersive combat style that's come to dominate gaming. Taking the controls of a tank, hunting down boxy, vector-drawn menaces, it was a 'proper' simulator that made shooting asteroids with a triangle look quite dull.
And you thought Donkey Kong was the first major platform game? A year before Nintendo's hero began its domination of arcades, Universal released Space Panic, players control a character who must take out waves of aliens by digging holes to push them into. There was no jump button, so ladders were the only way to move vertically. Without this, Mario would never have gone in search of Peach.
3D Monster Maze
Built by the UK team of designer J. K. Greye and programmer Malcolm Evans, the cassette-based 3D Monster Maze saw players dropped into a randomly generated maze that contained the terrible lizard. Limited to a first-person view, as the player moved about the maze, the T. rex would begin to hunt them down. It was the first ever horror video game, and proved that the genre was capable of something more than point-hunting.
Track & Field
In the early years of video games, tennis simulators were the go-to sports titles - hugely addictive but not greatly involving. In 1982, Konami released an athletics simulator that managed to group six events into one title. Such was the popularity of Track & Field and its scoring system that arcades around the world reported cabinets being broken or illegally adapted, as players sought new techniques for setting '100 Metre Dash' records. It proved that sports titles could be just as popular as alien invaders and arcade shooters.
Over 170 million. That's how many copies of Tetris have been shifted over the years, both digitally and physically. No grander narrative was required - other than you wanting to kill a few hours and chase a high score. The creator, Alexey Pajitnov, only started earning money from the game in 1996 when he founded 'The Tetris Company'. He made a handful of other games, but none proved anywhere near as popular.
With seven teams (including West Germany and Great Britain), Soccer arrived on the NES as the first 'proper' soccer game, with players that could run in any direction, passing options and a shot meter. The major faults lay in the way it used the NES controller, with many users complaining of cramped hands after a full 90-minute game - but it established a DNA that would pass into the Sensible Soccers and Pro Evos of later generations.
On its surface, Maxis' world-builder didn't sound like much of a laugh - a complex management game short on graphics and big on tasks (HEAVY TRAFFIC! Oh good). But this oddly addictive resource manager would go on to inspire a deluge of clones and spin-offs, from the brilliant Theme-Park to the vastly successful Sims series. We never could figure out how to stop the power station workers from striking.
Command and Conquer, Civilization, Age of Empires - every real time strategy game you care to list owes its success to this game. Based on Frank Herbert's sci-fi classic, players had to build an army, gather resources and seek to dominate the planet of Arakis, in blocky real-time combat. It's still hard as nails.
Before Quake, Duke Nukem 3D and Doom started setting all sorts of records - beginning the narrative of violent video games in the process - iD Software unleashed the grandfather of all first person shooters. Hugely popular thanks to its shareware copying, William "B.J." Blazkowicz's escape from castle Wolfenstein set down many of the 'laws' of the FPS genre. It was also a central title in shifting gaming away from arcades and into homes.
Pokemon (Red &Blue)
Go on - admit it. You've got the theme tune playing in your head right now? Somehow, this animal-collecting combat game had the right chemistry to become the biggest selling RPG series of all time, shifting over 10 million copies in its first outing. Incredible game design resulted in a huge title (for a Game Boy game) that could be played countless times with endless variation. It's subsequently helped Nintendo maintain its domination of the handheld market.
Not Metal Gear Solid, Final Fantasy, Tomb Raider nor Fifa. The biggest selling franchise across the PlayStation consoles started with a super realistic racer that sounded like an pensioner holiday tour. Back in 1997, the graphics and game physics were unparalleled, with rumours circling gaming magazines on how to unlock the fabled hidden Honda Del Sol racer alongside track guides and car stats. Without the success of this racer (it's sold some 10.85 million copies to date), PlayStation wouldn't be the brand it is today.
Where to start? The best licenced movie video game of all time; the shooter that helped keep Nintendo's N64 in the race with Sony's PlayStation; the game that introduced the majority console gamers to the delights of multiplayer combat; a superior control system, unlockable multiplayer characters, a 'heads-up-display' that didn't block the action. Rare's GoldenEye 007 might not be responsible for each of these elements, but it was the first to put them in a single package. That's it, we're off to dig our copy out of storage.
Grand Theft Auto
The blood, carnage and record-breaking sales of Rockstar Games' franchise was almost cancelled before launch due to production issues - but in 1997, it caused a tabloid stir that would become synonymous with the series. Sure, 1999's GTA 2 was a better game, but it was this first plucky title that introduced gamers to the controversial violence that would later translate into the biggest selling video game of all time.
The superlatives lined themselves up when critics first got their hand on Valve's sci-fi shooter, which scooped up 50 'Game of the Year' awards. With a revolutionary story that moved away from cut scenes to tell its narrative in-game, Gordon Freeman's journey through Black Mesa was only one aspect of Half-Life's legacy: the Counter Strike multiplayer expansion helped redefine online PC gaming, giving internet cafés the world over a serious revenue boost.
Halo: Combat Evolved
When rumours start circulating that Microsoft was entering the console business, many industry commentators were eager to declare it a brainless move: without a gaming legacy to match the likes of Nintendo and PlayStation, it was surely set to be a doomed venture. Bungie's game not only managed to launch a new console platform, it proved that console shooters could be as immersive as the more-capable PC shooters, setting a new standard of multiplayer mechanics, and with Halo 2, online console combat.
World of Warcraft
Over 100 million accounts have been created on World of Warcraft since its servers were first booted up in 2004. That means that if WOW was a nation, it would be the 13th most populated in the world, just after the Philippines. Besides its constant updates, vast community and dungeon raids, the real magic of WOW was in changing the nature of how a video game could make money, with its subscription service rewriting the rule book for online gaming.
Yes, Angry Birds was a game changer. Mainly because it changed the way that people played video games, helping kickstart the app revolution that would see more gamers take to mobile phones than any other platform to get their gaming fix. Some two billion copies have been downloaded since 2009, making it the biggest-selling app of all time.
You might not be one of them, but there are some one million people playing Minecraft right this very minute - with a whopping 100 million registered around the world. A simplistic, charming builder/adventure game, possibly the most remarkable aspect of Minecraft is its independent origins, with Markus "Notch" Persson eventually selling the title to Microsoft for $2.5 billion in 2014. It's on every platform you can imagine, from mobile to console, and the HoloLens functions set to arrive next year could see it change living room gaming all over again.