Doom didn't just revolutionize the first-person shooter; it changed the video game landscape as a whole. Its fast-paced, demon-slaying gameplay enthralled players back in 1993, and its addictive, competitive multiplayer destroyed office workplace productivity.

More than twenty-five years after release, Doom remains a thrilling experience, as proven by the recent ports of the original games to modern hardware. One of the people responsible for the game's development and outstanding success is John Carmack. The veteran game designer worked on countless other classics as well like Wolfenstein 3D, Commander Keen, and Quake. The following ten entries will present ten lesser-known facts about this influential industry pioneer.

10 Criminal Past

John Carmack talking on a stage
John Carmack talking on a stage

As a youngster in his native Kansas, John and a group of other teenagers attempted to steal computers from a school. Being about as adept at crimes as typical teenagers are, their plan failed and Carmack was caught. Because he was a minor at the time of this indiscretion, he avoided any lengthy jail time, but spent a year in juvenile detention. To be fair, a year for a teenager is an eternity. Fortunately, his hard criminal ways are long behind him, and his energy is better spent crafting bleeding edge technology for awesome video game experiences.

9 Introduction To Video Games

John Carmack Talking Into A Microphone
John Carmack Talking Into A Microphone

Most gamers discovered the medium at a young age and can vividly recall their first run-in with a console or arcade. Game designers are usually no different, save for Dark Souls' creator Hidetaka Miyazaki, who didn't play games until adulthood. John Carmack's first experience with video games was in the arcade, with Pac-Man and Space Invaders having the biggest impacts on him.

Related: 10 Things You Never Knew About Hidetaka Miyazaki

They are far cries from the blood-filled experiences he'd craft in his professional career, but one can see the maze-like levels of Doom and Quake coming from the literal mazes the hungry circular character runs through.

8 Rocketry

John Carmack Talking In Front of an Ipad
John Carmack Talking In Front of an Ipad

Being a programmer and more focused on technology, one shouldn't be surprised that his hobbies lean heavier into a scientific field rather than the artistic. Carmack became infatuated with rocketry at the turn of the millennium, and started investing money into his newfound fascination.

Related: 5 Best Weapon Upgrades In Doom (And 5 Worst)

He eventually founded Armadillo Aerospace, which had the lofty goal of accomplishing spaceflight and starting space tourism. It never made its goal, otherwise the whole world would be worshiping Carmack at this very moment.

7 Current Career

John Carmack With Oculus Shirt
John Carmack With Oculus Shirt

Carmack left Id Software, the company he cofounded, in 2013 to work as the chief technology officer at Oculus. The game designer was fascinated with the prospects offered up by the burgeoning VR technology, but his position at Id was limiting his time and resources to explore such possibilities.

Related: 10 Facts About The Cancelled Doom 4 You Never Knew

As a result, he made the decision to leave the company and focus full time on VR. His presence is missed at Id, but the company forever owes him a debt of gratitude.

6 Lawsuit

John Carmack talking with Ipad in hand
John Carmack talking with Ipad in hand

While the split between Carmack and ZeniMax, Id's parent company, seemed amiable, it did spawn two lawsuits. The first was ZeniMax claiming Oculus stole their VR intellectual property. Carmack himself wasn't held responsible, but Oculus was found liable to the tune of half a billion dollars.

Related: 10 Most Powerful Main Characters In First-Person Shooters, Ranked

The second suit saw John take his former employer to court over unpaid wages. This suit ended in private with little fanfare. When money and trade secrets are involved, things sure can get nasty.

5 He Loves Pizza

Electronic Arts E3 Press Conference
Electronic Arts E3 Press Conference

This may seem unremarkable at first⁠—saying "I love pizza" is about as informative as stating "I like breathing,"⁠—but it's the extent of his admiration for the Italian cuisine that is truly impressive. Allegedly, Carmack would order a medium pizza daily during his time at Id. Any normal person would have fatally succumbed to such a diet after more than a decade, but Carmack seems to be in good health. We hope he doesn't indulge in it as much these days, however, since an older body generally can't handle unhealthy foods like a younger one can.

4 The Name Doom

Tom Cruise Color of money
Tom Cruise Color of money

The word Doom perfectly encapsulates the game's ideas and mood, but it doesn't make that much sense when one really thinks about it. We supposed in biblical terms "doom" might have something to do with Hell, but it really just sounds cool.

Related: 10 Things You Didn't Know About Doom

The name, as it turns out, was John's idea, and comes from a line Tom Cruise says in Martin Scorsese's The Color of Money. When someone asks what he has in his pool cue case, Cruise opens it and says, "Doom."

3 Family Life

John Carmack with his wife
John Carmack with his wife

John Carmack married Katerine Anna Kang in 2000 at a ceremony in Hawaii. Katherine founded Fountainhead Entertainment, where she produced a variety of Machinima pieces. In addition to her pioneering work in that field, she also directed several mobile games at Id software, including the highly venerated Doom RPG and Wolfenstein RPG. These titles are especially noteworthy because they came out when mobile gaming on cellphones was still in its infancy.

2 His Last Work At Id Software

Doom SnapMap
Doom SnapMap

While Carmack left Id long before 2016's Doom hit shelves, he still has a small footprint on the title. According to his Twitter, Snapmap was the last thing he worked on before leaving for Oculus. By his own admission, the final Snapmap was way different than what he was doing, but he was there for the beginning stages. Snapmap had promise, but some of its odd limitations, like the inability to use the maps in regular multiplayer, squandered its potential.

1 Ferraris

OLYMPUS DIGITAL CAMERA
OLYMPUS DIGITAL CAMERA

It's amazing the types of hobbies one picks up once they start making some money. Most people settle for music collecting or painting. Carmack, on the other hand, has a particular fancy towards Ferraris. These cars are famous for their glamour and speed, with anyone buying it basically stating, "Look how rich I am." Though far it be from anyone to tell a successful person how to spend their money. Carmack gave away one of his Ferraris to a Quake tournament winner, so it's not like he's completely selfish with his earnings. The money he used to spend on Ferraris was eventually channeled into his rocketry hobby.

Next: 5 Things About The Original Doom That Haven't Aged (And 5 Things That Don't Hold Up)