Answer: Procedural Generation

For most of video game history, video games have featured two key components: they’ve had limited content and they’ve been closed worlds. In other words, the games had a set start, middle, and ending, and within that linear story line you couldn’t go off the road map, so to speak. In classic games like the side-scrolling Super Mario Bros. series, to use a very well known example, you start at point A, you work towards point B, and at no point can you stop trying to save the Princess and instead climb out the castle window and go play in a field. Further, no matter how many times you play the game, the levels are identical.

There is, however, a variation of video game design that allows for a more varied player experience: procedural generation. In traditional video games, a team of designers lays out the game and designs all the levels much like a movie director laying out all the scenes in a film. In procedurally generated games the levels aren’t individually created by the game designers, but are instead created by a computer algorithm designed by them.

While there have been more than a few games over the years that featured procedural generation (stretching all the way back to the 1978 release of Beneath Apple Manor, which used procedural generation to construct dungeons for ASCII-based systems), the most famous procedurally generated game around, both in cultural impact and sheer sales, is Minecraft. In the game, every map is uniquely based on the seed which was used to create it (by default the seed is the precise time at which the world is created, unless the time is manually specified by the player). Players could create a new world just fractions of a fraction of a second apart from each other and those worlds would be completely unique with mountain ranges, rivers, caves, and dungeons unseen by any other player in the history of the game. Further, players are free to roam wherever they want (and for as long as they want) in true open-world play style.

Thanks to procedural generation, video game designers are able to create games which have nearly infinite variety and a very high replay value thanks to the uniqueness of each play experience.