This story was originally published in December 2013 for Doom ’s 20th anniversary. We’ve updated it in reflection of the game’s 25th anniversary.

Doom may well be the most influential game of the last three decades. As it marks another birthday, it's a work that is worth celebrating.

Leaving aside the usual plaudits and the warm nostalgia, it is also worth asking just how important the game is in the great scheme of modern entertainment. Noted at the time of its launch for its technological achievements and its violence, its legacy now seems to be as an early catalyst in multiplayer gaming, in literally bringing people together around a single video game.

Marking the game's birthday at a gathering held on the University of California, Santa Cruz, campus on Sunday, Dec. 8, 2013, a few of its creators came together to discuss its importance, along with Professor Henry Lowood, a technology historian based at Stanford University.

Part-lecture, part-LAN/social-academic gathering, the Doom party sought to affirm the game's place in history, and why it means so much to people. John Romero, the game's designer, is regularly recognized in the street. People will approach him and talk about how much Doom meant to them, growing up. They will often talk about how it filled a gap in their lives.

At the party, there were many game design students, studying under a program organized by John and Brenda Romero, for whom many of the design fundamentals of Doom are hard-wired into their view of what games can be. To play Doom against other people is basically the same as playing the most modern shooter. Certainly, in the deathmatches that sprang up, the partygoers shared an enjoyment that few 1993 games could really emulate today.

The question of how far its influence spreads is a matter of spirited debate. In his well-regarded book about developer id, Masters of Doom, David Kushner tried to make the case that the game had transformed popular culture. Reviewing the book when it was published ten years ago, the influential critic Wagner James Au argued that its power, while significant inside gaming, had spread no further, that the game was a technical feat just waiting to be achieved, overlain with some standard action-horror assets.

Today, separating games from mainstream culture is a more problematic notion than 10 or 20 years ago. Our movies, our communication devices, even our sports, are all intertwined with gaming. And gaming, without any doubt, has been shaped by Doom.

It spawned a genre called Doom clones, now known as first-person shooters, which are, for many people, the very definition of 'video game.' The importance of FPS games like Call of Duty: Ghosts and BioShock Infinite speak for themselves. They follow the same structures as Doom. They feature, essentially, the same weapons.

Of course, Doom was not the first FPS. "We had made five first-person shooters before Doom," said the game's writer, Tom Hall, now head of PlayFirst. "We released Wolfenstein, which had been a hit. But this was the first that had multiplayer, the one that innovated in lots of ways that are now standard in shooting games."

It may not be the first FPS, but it was the first FPS game that millions of people played, many of whom were seeing, for the first time, first-person game worlds that were not abstractions but which operated in the same way that they experienced life. In Doom, the player moves through a world, at a rapid pace, interacting with things. This was not the same as playing sideways-view or overhead experiences like Pac-Man or Super Mario Bros.

Professor Lowood, giving his speech at the party, argued that it was also the first game to separate an "engine" from the game's assets, and in so doing, purposely allowed users to create mods and machinima easily. This played into the growing culture of the independent developer, and of the consumer as creator. It might be fanciful to credit Doom with facilitating this, but it definitely played a part in fostering the understanding that anyone could play with a pre-made engine and create levels or movies out of the technology.

This was something that Romero and John Carmack, the other half of id's core team, worked together to realize. Carmack's zeal for open-source tech partnered with Romero's love of creating fun and, in his words, "anything that might be cool."

Carmack was not at the 20th birthday gathering. It has been a very long time since he and Romero have worked together. Masters of Doom portrayed their relationship in Lennon-and-McCartney terms in which their differences eventually outran their similarities. Romero said that he would have invited Carmack, but doesn't have his email address, since he left id. This suggests a relationship that falls somewhere short of exchanged Christmas cards.

The game can claim some credit for our culture of consumer creativity, but there is another area of our culture in which its place is more solidly secure. When Doom came out it offered a multiplayer option, that quickly became extremely popular. Interestingly, Romero said that the multiplayer part of the game was only included at the very end of the project. "We started working on [the multiplayer] in October [1993]," he explained. The game was released in December.

When the game was launched, it revealed a demand to play against others. "People would grab those heavy old PCs and monitors and transport them to a friend's house and spend half a day networking them all together," Romero told Polygon. "Then they'd spend days just playing Doom. It was the intensity of the experience that people remember."

Multiplayer gaming was nothing new in 1993, but thousands of people moving computers around in order to play for long sessions, electronics stores unable to cope with demand for networking dongles, workplaces instigating rules about playing this one game on their networks, that was all new. Within a few months, the most savvy players had figured out how to play the game over the Internet, a complicated matter best left to those with deep technical knowledge and lots of patience.

Doom showed that the appetite for running around and shooting your friends was enormous. Today, multiplayer gaming, the culture it has created, the e-sports leagues and memes and 'let's plays', are something that are both unique to gaming while also belonging to the human culture as a whole. Those guys organizing LAN parties were finding a new way for people to play together and it is still being felt today.

"People spent crazy amounts of time deathmatching," said Romero. "It was so intense and it brought people together in ways that were new. That is why I think Doom still means so much to people, why people I have never met say hello to me when I pass them in shopping malls, they had fun in ways that they will never forget."

In a Q&A session, a student asked Romero if he understood that the game would be so enormous. He said that, yes, the id team had understood that it would be a big hit, but that at the time "we were just trying to make a game that was better than the ones we had made before."

Doom's place in history may not be based on its provenance as the first FPS, it may not even be as the first game to come with a self-contained engine that encouraged modders. But its place as a game that bound people together like never before, is its likely legacy.