When released in 1998,Half-Life was so ahead of its time that it actually rarely gets credit for all of the innovations it introduced to the shooter genre and gaming as a whole.Things like scripted story sequences that play out without cutscenes have long been associated withHalf-Life, but theres more to Valves PC shooterthan just its game-changing approach to storytelling. From grenade throwing to mods, Half-Life changed how you play video games in ways that you may not even realize.In terms of impact on PC gaming, Half-Life stands as one of the most important titles ever released. Valves PC shooter is not only one of the titles that defined gaming on your computer in the late 90s, but an experience that few developers of that era could match in terms of artistry and quality. For years, you could argue that there was really only oneHalf-Life.To celebrate over two decades of Half-Life, lets look at the innovations that made this classic one of the most important PC games ever released.A Surprising Degree of RealismRealism probably feels like an odd word to use when talking about Half-Life. When many of todays shooters force us to stay hydrated, eat, and take our vitamins, thats probably not the way modern gamers would choose to describe an FPS that ends with a trip through an alien dimension.Yet, so many of Half-Lifes best touches are grounded in realism. The most famous example of this is humorously highlighted in the games manual, which boasts that in-game weapons are found in practical locations rather than just floating in the air. Titles like GoldenEye 007 played with similar ideas, but there really is an internal logic to the location of nearly every gun and item in Half-Lifethat goes beyond whether a gun is floating magically or laying in wait.On top of that, youve got impressive details like the fact that crossing a body of water that is touching an exposed electrical source will electrocute the player or enemies. It all sounds simple, but in an era when the shooter genre was still trying to escape the Doom clone label, this is one of the ways that Half-Life showed that even more action-oriented FPS titles could still benefit from a dose of realistic design.The Logic of the HEV SuitPrior to Half-Life, the concept of health and armor in most first-person shooters (and many other games for that matter) was pretty simple. You would just pick up health packs, armor, and power-ups as you went along, and you didnt ask any questions. Half-Life changed all that by introducing Gordon Freemans HEV suit during the games opening sequence.Not only did the HEV suit serve a practical purpose in the games story (its used to protect Freeman during the experiment that sets the story in motion), but it assigned a logic to in-game items, which at the time were usually treated as if they were magic mushrooms in Super Mario. Health was what kept Freemans body alive, while the suit, which functioned as additional armor, needed to be charged in order to continue protecting Freeman from harm. Health and recharge stations were also found in locations that generally made sense to the environment and narrative. It also featured a toggleable flashlight, which was either the first appearance of that mechanic in an FPS or a very early example of it.You could argue that the relationship between Gordon and his suit would even lead to things like the rechargeable shield in Halo: Combat Evolved. Interestingly, later games kind of went the other way by allowing characters to just magically heal by finding cover or resting, but there was a period when assigning logic to how a players in-game health worked in FPS titles was all the rage.Enemies, Grenades, and YouMuch has already been said about Half-Lifes revolutionary enemy and companion A.I. Yet, the ways in which Half-Life changed the art of PvE first-person combat can best be summarized by what happens when someone in the game throws a grenade.If you throw a grenade at human enemies in Half-Life, they will usually run away. If you are trying to hide behind a wall or box in the game in order to lure soldiers to you, they will typically use a grenade to flush you out or outright kill you. Non-human enemies are less likely to run from grenades, but thats because they dont really understand what they are.It all sounds simple, but Half-Lifes use of grenades showcases two concepts you didnt typically see in most FPS titles of the day. The first is that your enemies actually have a desire to live or, at the very least, live long enough to kill you. The second is that you wont be able to fight a highly-trained soldier the same way you would fight a shuffling zombie.Combined, those two details alerted players to the fact that winning every battle in this game wasnt just a matter of circle-strafing an enemy while firing your largest weapon. Instead,Half-Lifes grenade mechanic pushed players to employ a little creativity to survive the most intense combat sequences.A Cohesive FPS EnvironmentThe most notable first-person shooters released before Half-Life (Doom, Unreal, Hexen, etc.) didnt necessarily suffer from lackluster level design, but few of them really sold the idea that every level was part of a larger world.Half-Life accomplished this in a few notable ways.On the technical side of things, Valve created a fairly large in-game world where much of the loading happened behind the scenes. This meant that players didnt have to regularly stare at loading screens and experienced noticeably less loading as they moved from area to area. As a result, you felt like you were truly navigating a large and immersive research facility rather than bouncing between traditional gaming levels that felt unrelated to one another.However, this innovation is about much more than just technical accomplishments. The Half-Life team designed each area of the games map to feel like a place that existed for a purpose, even if that purpose didnt directly impact your path through the game in a notable way. There were break rooms, labs next to labs that were studying similar subjects, and numerous instances of objects and environmental events that made the Black Mesa research facility feel more real.This is something of an odd innovation as even the great FPS titles that would follow elected to adhere to a more traditional level/mission-based structure. Still, Half-Life raised the bar in terms of environmental design in ways that are still noticeable today.Different Kinds of Action PuzzlesMany of the FPS games released after Doom followed that games playbook in terms of puzzles and non-combat obstacles. In other words, most of those titles required you to collect keys or passcards in order to progress to the next area. It was a simple way to throw in some hurdles without forcing the player to drop out of combat for too long.Half-Life did things a little bit differently. The most obvious examples of its approach to a better class of puzzle design involve memorable sequences such as the one where you must find a way to launch a missile in order to remove an otherwise unbeatable enemy that is attracted to sound and will instantly kill you if it hears you. Most FPS titles from the 90s didnt feature such elaborate obstacles that expertly combined stealth, multi-step solutions, and even a dash of horror-based tension.Yet, Half-Lifes best (and most influential) puzzles were found in the combat itself. Half-Life forced you to adapt to what your enemies did and also consider other ways to survive encounters beyond blasting everything in your path. Such encounters adhered to the primal pleasures of the genre while still requiring the player to utilize a little brainpower from time to time. Obviously, Half-Life 2 would expand on this concept with its use of physics-based combat (especially in the legendary Ravenholm sequence).For a game that is sometimes implicated in the death of the pure FPS, Half-Lifes combat sequences and organically integrated puzzles sections showed that fetch quests werent the only way to add puzzles to the genre.A Smarter Weapon Progression SystemIn many of the FPS titles that precededHalf-Life, weapon progression was fairly simple. You usually used whatever gun you picked up until you found a better one. There were exceptions (Dooms shotgun was a somewhat notable example), but the idea was that weapons were closer to power-ups that gradually improved over the course of a game and were generally only limited by ammo.Half-Lifes introduction of the crowbar was its earliest and clearest declaration that it intended to break the weapon wheel. Despite being the first weapon you received in the game, you end up using the crowbar throughout Half-Life as both a tool for breaking boxes and arguably the best weapon against certain enemies (such as Headcrabs).While some weapons in Half-Life are arguably replaced by better versions of a similar concept (the MP5 fairly easily replaces the pistol), youll end up using most of your weapons until the end of the game. It all depends on what youre fighting and what the situation calls for. A rocket launcher is great against a helicopter, but its not really practical in many of the games confined areas. Trip mines can be devastatingly powerful, but they also require clever placement. Shotguns work great against lumbering monsters that get in close, but they do less against soldiers who keep their distance.Not every FPS game that followed Half-Life walked this path, but here again, we see another example of how Half-Lifehelped show there was a different way to do things.Improved Sequence Scripting and Set PiecesFile this one under controversial innovations, but Half-Life certainly raised the bar when it comes to scripted in-game events (especially in a first-person shooter).Half-Lifes own GoldSrc engine may have relied heavily on the Quake engine, but Valve managed to tweak that technological source in fascinating ways that greatly advanced the potential of the genre. One of their most important tweaks was the creation of a new scripting tool that made it easier for developers to not only create more elaborate scripted sequences but to allow the player to interact with their environment like never before.While the most positive examples of this innovation are Half-Lifes grand set pieces, its really the smaller moments that secure the games place in history in this respect. For instance, the ways that you interact with NPCs and small environmental elements in this game feel commonplace now, but it was anything but back in 1998.Some say that Half-Lifes innovations in this field eventually led to an era of overly-scripted shooters, but Half-Life actually found a nice balance between offering set pieces and allowing the player to feel like they were organically experiencing a journey.More Accessible ModdingDoom will always hold a special place in PC gaming history as the FPS title that helped modding reach the mainstream. However, Half-Lifes contributions to the mod scene are often overlooked despite the fact that Half-Life mods like Counter-Strike rank among the most important PC titles ever.Valve made the decision early on to allow the Half-Life community to easily access the design tools that powered the game. This not only led to more people playing around with modding but experienced mod creators enjoying nearly unprecedented access to a developers toolbox.Not long after, other studios started to catch on to the idea that the community isnt just there to buy your game and maybe swap some textures around. Instead, its possible that they can not only fix issues present in the base game but create experiences that the original development team would have never dreamed of, greatly expand the lifespan of the title in the process.