Art may largely be a matter of taste, but one conclusion is close to inarguable: 1998 was the best year ever for video games, producing an unparalleled lineup of revolutionary releases that left indelible legacies and spawned series and subcultures that persist today. Throughout the year, The Ringer’s gaming enthusiasts will be paying tribute to the legendary titles turning 20 in 2018 by replaying them for the umpteenth time or playing them for the first time, talking to the people who made them, and analyzing both what made them great and how they made later games greater. Our series continues today with a look at Half-Life, a revolutionary first-person shooter whose influence has only grown stronger over the years.

Hosea, Charles, and I are in a carriage riding south alongside a roiling river. We’re heading for Horseshoe Overlook, planning to set up camp and lay low for a while. It’s a beautiful spring day. I’m struggling to pay attention as Hosea fills me in on the history of this fertile land and how it was violently ripped away from the Native Americans who once lived here. It’s an awful, tragic story, contrasted starkly by the overwhelming beauty of our surroundings. After a few more minutes of ruminating about the fleeting nature of life, our conversation trails off, but the unnerving words linger in the crisp air. We ride the rest of the way in silence except for the sounds of our rickety carriage and plodding horse hooves, with the river at our side and birds soaring overhead.

Red Dead Redemption 2, which came out earlier this month, is easily one of the most immersive games of all time—rich with story, full of dialogue, and overflowing with detail. My ride to Horseshoe Overlook was an experience that set the tone for my new surroundings. The game could have easily showed me a cutscene and plunked me down at my next location. Instead, I was present for the whole journey. While listening and observing—and consequently, intensifying my connection to the game world—I drove my crew to Horseshoe Overlook.

Twenty years ago, I took a similar journey, only this time on rails. Through the chunky pixels of a CRT computer monitor, I looked out the windows of a tram car as I slowly made my descent deeper and deeper underground into the heart of the Black Mesa Research Facility. A slightly inhuman voice unravelled procedural information over the tram’s loudspeaker for the duration of the ride as I marveled at the scale and complexity of my bustling industrial surroundings. I felt uneasy.

Released in November 1998, Valve Software’s Half-Life changed the way we experience video games. Half-Life sought full player immersion in its game world. In the heyday of video game cutscenes, there were none. In an age of long loading times, Half-Life found clever ways to hide them, creating the illusion of a fully connected, seamless environment from start to finish. Half-Life was a conceptual and technical marvel at the time of its release, and its influence is more enduring and wide-reaching than we could have imagined 20 years ago. It still sits in a tie for the highest-rated PC game of all time on Metacritic—a tremendous accomplishment, especially when you consider that Half-Life was the first game released by Valve. Valve cofounders Gabe Newell and Mike Harrington essentially won a championship in their first year in the league.

Half-Life stars the somewhat controversially mute Dr. Gordon Freeman, a crowbar-wielding MIT grad with a degree in theoretical physics. A new employee at the ominous Black Mesa Research Facility, Gordon quickly finds himself fighting for his life after a failed experiment rips a tear between dimensions and unleashes a horde (gaggle? pride?) of aliens upon the facility’s inhabitants. What begins as a fairly routine plot of monster invasion soon becomes much more nuanced as Gordon encounters a military agency dispatched to cover up the incident. Released in the same year as the X-Files movie, Half-Life’s main “bad guy” is not an alien, but rather a shadowy, omnipresent agent known only as G-Man.

At the time of Half-Life’s release, PC first-person shooters like Unreal, Quake II, and the racially problematic Shadow Warrior were very simple player-versus-everyone affairs. All of the bad guys were out to get you—the grizzled one true hero. Gordon Freeman, however, was caught in the middle of a plot that was much bigger than himself. There are moments of being trapped and helpless in Half-Life. There’s a built-in vulnerability that drives the player to panic as you stumble into situations that no physicist should be able to handle on their own. You’re not always expected to kill the huge monster in the room—you’re expected to find a way to survive another minute. A world is more believable when you don’t perceive yourself as being at the center of it.

Half-Life’s innovations in immersive storytelling and game-world fluidity can’t be understated. We take them for granted in modern games. But some of the more dated elements of Half-Life are hard to miss upon revisiting Black Mesa. They ripped a hole between dimensions, so obviously there’s some heavy-hitting science going on, but it would be easy to mistakenly believe that the primary focus of the facility is actually the study of empty or near-empty wooden crates. (They are everywhere.) The voice acting is quite uneven. The AI is buggy. The same handful of character models are repeated ad nauseam. If we really want to scrutinize a landmark game an unfair number of years after its release, there is a lot of room for improvement in Half-Life. But there’s also undeniable charm in many of Half-Life’s imperfections. There’s a winking dark humor in seeing the same scientist model over and over again in new distressing situations. There are subtle nods to the camp of B-horror movies. Half-Life was clearly a labor of love, but it never took itself fully seriously. It oozed personality and provoked curiosity at a time when first-person shooters mainly peddled inarticulate machismo.

In retrospect, one of the most incredible elements of Half-Life’s legacy is that its off-the-charts review scores were doled out when the game barely had an online component. It was only after receiving countless accolades that Half-Life evolved into something that completely revolutionized the online gaming landscape. Half-Life was released in 1998, but online, it’s still evolving today.

Having won more than 50 game of the year awards on the strength of its single-player campaign, Half-Life also originally shipped with an online multiplayer “deathmatch” mode. Here’s what IGN had to say about Half-Life’s initial multiplayer offering in its 1998 review:

It’s obvious that Valve spent all its time and energy perfecting the single player experience, and so as far as deathmatches go, Half-Life’s is just that, a standard deathmatch. But who cares? You shouldn’t be buying this game to play deathmatch.

At the time, IGN was right. Half-Life’s multiplayer experience felt like an afterthought. The bread and butter of the game was so clearly the single-player experience. Was Valve forced to tack on a trendy online game mode? Did it even care about providing an online multiplayer experience? Well, it turned out that Valve had big plans for Half-Life’s multiplayer—plans that could begin only after the game had been released: The company outsourced the development of multiplayer modes to its fans.

At the start of the game’s development, Valve licensed the existing Quake engine from Id Software and used it as a foundation to build upon. The result of Valve’s extensive modifications and additions to the Quake engine became known as GoldSrc (or “Goldsource”). Valve also created a piece of level-editing software called Worldcraft (later renamed Valve Hammer Editor), which the company used to design all its game environments. Both the GoldSrc engine and the Worldcraft level editor were eventually released to the public, for free. Inspired by Id Software cofounder John Carmack’s open encouragement of user modifications to the Doom and Quake series, Valve encouraged novices to dive in and design their own maps, or even create their own games using the engine. Valve provided documentation and resources to anyone trying to understand their tools. The user-made games that came about from modifying Half-Life were known as “mods.” Before long, teams of strangers who had never met in real life were assembling in online forums to make their own mods. Mappers hooked up with texture artists who knew someone who could massage GoldSrc code. Entire communities sprung up around the creation of Half-Life mods. Similar communities already existed for games like Quake, but Valve made modding easier than ever and virtually every PC gamer already had a copy of Half-Life. You didn’t need a computer science degree to make your own Half-Life map. You just needed Worldcraft and some time and patience.

Promising mods emerged from the community that Valve fostered. In 2000, Valve purchased the rights to Counter-Strike—a mod that featured SWAT-inspired gameplay. Counter-Strike raised the stakes for online first-person shooters: Damage from one bullet could be fatal and fallen players stayed dead until the end of each round. Counter-Strike’s creators, Jess Cliffe and Minh Le, were not only paid for the rights to their mod but also hired on at Valve to continue to develop it. Valve made similar arrangements with the development teams of Team Fortress in 1999 and Day of Defeat in 2003. The fourth game in the Counter-Strike series—Counter-Strike: Global Offensive—had more than 11 million unique players in October 2018. A professional players association was formed earlier this year. Team Fortress 2 is estimated to have been played by more than 50 million people. Valve opened Half-Life up to the world and supported its community, and it’s still benefiting from that decision nearly 20 years later.

The wide-reaching influence of Valve’s games is easy to spot in the present-day gaming landscape. Would Overwatch even exist if it weren’t for Team Fortress? Probably not. Overwatch developers consider Valve’s Team Fortress 2 team to be “geniuses.”

And if it weren’t for the success of Half-Life, Valve would never have created Steam—the digital distribution platform they launched in 2003 that is now the largest digital PC game distributor in the world, with sales of over $4 billion in 2017. If you’ve never played Half-Life or would like to revisit it, I have a suggestion for a game you should download in Steam: Black Mesa. It’s a higher-res, painstakingly faithful (and sometimes respectfully embellishing) re-creation of the original Half-Life, created entirely by a group of adoring fans who had absolutely nothing to do with Valve. It took them eight years of hard work to make. Valve could have sued them into oblivion. Instead, Valve proudly sells Black Mesa in its online store and allows their development team, Crowbar Collective, to profit from their work. Xen, the final chapter of Black Mesa, will be released in Q2 of 2019—21 years after the members of the Crowbar Collective were initially inspired by a mute nerd smashing open empty crates. Or if you’d rather revisit the very first, original Half-Life from 1998, now’s a great time. Valve just released a new patch for it a few weeks ago.

In physics, “half-life” is a term used to measure decay. The “half-life” of something is the amount of time it takes for that property to decrease to half of its initial value. Improbably, after two decades, Half-Life’s value to the gaming world has remained constant.