On June 22, 1996, id Software released Quake, an evolutionary leap not only for first-person shooters, but for the industry at large. But before id could leap, it had to learn how to crawl.

In 1991, id released two landmark games that don't get nearly enough recognition today. The first was Hovertank 3-D which, while not the first first-person game nor the most detailed, was easily the fastest. Catacomb 3D built on Hovertank's foundation by applying texture maps to surfaces, transforming flat, single-colored areas into dungeons built from bricks and covered in slime and gore. On a smaller note, Catacomb 3D was the first FPS to show the player-character's disembodied hand.

Then the id crew made Wolfenstein 3D, and their advancement hastened from a crawl straight into a run. Programming prodigy John Carmack rendered corridors and walls in pseudo 3D by using raycasting, a rapid-fire series of tests that cast invisible lines called rays in every direction to detect the location of the next physical object, before painting them with textures. Doom upped the ante in 1993 by stretching Wolf3D's boundaries. Rooms varied in height and width, staircases and elevators connected platforms, and flying enemies like Cacodemons and Lost Souls could swoop over land monsters like Imps... or so it seemed.

Doom's 3D playground was wrought from smoke and mirrors. It was fast, but incapable of executing true 3D environments. Enemies only appeared to fly over or walk underneath one another, and no two platforms could be made vertically parallel. Nevertheless, Doom popularized deathmatch, a mode where two or more players could blast each other to bits over modem or network connections, as well as mod tools that let players build their own maps and campaigns.

Enter Quake, a revolutionary game made by a small team—less than two dozen developers. Yet despite id's small stature, Quake quickly grew into a giant whose technical pedigree and deceptively simple gameplay notions set the standard for FPS and 3D titles going forward.

True Blue (and Brown) 3D

Breaking down the technical obstacles that had curbed Doom's engine, Quake rendered worlds in three dimensions. Rooms and platforms could be stacked; enemies such as the slug-like Scrag could fly over and under actors; lightmaps fashioned through a combination of real-time and baked-in effects like shadows and flickering lights; and physics brought about new ways to navigate levels: rocket jumping, the process of jumping while firing a rocket at the ground to blast off to out-of-reach areas, and bunny hopping, moving at a sprint while strafing and pressing jump in a Twister-like feat of finger gymnastics.

More impressive than any single technical feature was the fact that Quake's engine produced capacious military compounds and Lovecraftian castles on Intel's relatively new Pentium processors. Carmack hired on Michael Abrash, a programmer renowned for making strides in graphics programming in and out of the games business, to help nail down fine details.

Quake may have dispensed with Doom's optical trickery, but Abrash and Carmack employed plenty of shortcuts to blast polygons to the screen. After finalizing a map, id's designers put it through a lengthy compilation that winnowed away excess surfaces. During play, algorithms shaved off yet more surfaces outside the player's view; rotating the camera toward them popped them back into view. At the same time, a separate process determined a line of sight so players could see items and enemies.

The Wide World of Quake

Quake took online play to the next level by implementing TCP/IP protocol, allowing multiple players to join servers through their modem just as if they were connected to a network. When it became apparent to id that players competing over phone lines were hobbled by latency issues, Carmack joined forces with a couple of other programmers to write QuakeWorld, an update pushed out in December 1996.

QuakeWorld used client-side prediction algorithms to iron out issues for players dialing into Internet servers from a modem. It wasn't as silky smooth as broadband Internet, still years away from becoming ubiquitous, but it was more than good enough. So good, in fact, that friends and foes met through the game and formed teams known as clans.

Fueled by nerdy adrenaline and buoyed by Carmack's code, clans led to the advent of eSports, where names like Dennis "Thresh" Fong and Jonathan "Fatal1ty" Wendel earned paychecks by becoming professional players.

Quake Accelerated

Rendered in software like any other FPS, Quake looked great. Fueled by the growing supply of 3D graphics cards, it looked spectacular. Long before NVIDA and AMD competed for consumer dollars, 3dfx's line of Voodoo chipsets made eyes bug out when players got a gander of GLQuake, a free update for the game written by id and optimized to take advantage of OpenGL graphics standards.

Night-and-day differences separated Quake running in software versus OpenGL libraries. Water was transparent, glass textures showed reflections, gun muzzles flashed, and rockets streaked across the screen surrounded by their own glowing balls of light.

GLQuake was at least partially responsible for PC gamers' obsession with framerates and higher resolutions. The update supported resolutions unavailable in the original games such as 1280x800, and switching from 16- to 32-bit color depth sharpened graphics even further. To keep the game running as fast as possible, players spent hundreds of dollars on RAM, processor upgrades, and the latest and greatest offerings from 3dx, which always sported more video RAM than earlier models.

Look, Mouse!

Quake did not invent mouselook. That honor goes to Ultima Underworld, released in 1992. Descent allowed players to toggle the option, and one could argue it was necessary to properly navigate the game's topsy-turvy world, predicated on offering six degrees of freedom.

However, mouselook was not a given. Some games had it, some didn't. Quake is considered the first game to make it practically necessary: players who flipped the mouselook switch dominated their keyboard-only opponents in deathmatch.

Console-ized

Quake's underpinnings were so flexible that id had no issues letting players redefine them to further shape their gameplay experience. Pressing tilde opened up a text-based console where players could change control bindings, movement speed, gravity settings, and even how far back players should stagger when shot.

Launch Pad

Devotees of Quake can have just as much fun playing the game today as they did 20 years ago today. Still, those who missed the polygonal boat (rendered in OpenGL) might wonder what all the fuss is about. What relevance does Quake have today?

Simply put, Quake, while great in its own right, also served as the bedrock for a litany of new ideas. Carmack, Abrash, and id's other coding gurus wrote the game in a scripting language known as QuakeC, and then passed it along to players. Thanks to its free cost of entry, players were able to put together mods like Team Fortress and Threewave Capture the Flag—modes that became standards in later FPS titles.

Quake also bridged the gap between id's style of FPS—shoot all the things en route to collecting keycards and heading toward the exit—and Valve's Half-Life, the next chapter in FPS design: cohesive environments, scripted events, and narrative- rather than goal-driven directives. Valve, a scrappy company in the mid-90s, used Quake's engine as a springboard for their ideas, drastically overhauling the engine to accommodate larger environments, smarter enemy AI, and other innovative tech considered run-of-the-mill in today's games.

Twenty years from now, like today, Quake will still be sending aftershocks through the industry.