I don't remember which game we were playing, but it was the kind of Japanese RPG that listed everything you needed to know about its characters down the side of the screen. Magic points, coins, food, all summed up with helpful numbers. Only one of them was abbreviated: HP.

“What does HP stand for in this game?” I asked my friend, an expert on JRPGs.

“Health pineapples,” he confidently replied. “You have to knock all the pineapples off before you can hurt someone.”

HP, whether it stands for hit points, health power, or indeed health pineapples, is one of many mechanics to come to video games via the original tabletop roleplaying game Dungeons & Dragons. However, the idea of representing the amount of punishment a character can take with a discrete number of points is much older than D&D. And while we might all know what the abbreviation means, it turns out that what hit points are meant to represent isn't quite so obvious.

In a 2004 interview with GameSpy, D&D's co-creator Dave Arneson explained that the earliest version of the game didn't have hit points. The rules had evolved from wargames he and fellow D&D inventor Gary Gygax played, in which a single successful attack was all it took for a soldier to die.

That changed when they started experimenting with having players control individual heroes rather than entire armies, as players identified with them much more strongly. As Arneson put it, They didn't care if they could kill a monster in one blow, but they didn't want the monster to kill them in one blow.

Arneson had previously made his own rules for a naval wargame set during the Civil War called Ironclads, and together with Gygax had collaborated on a Napoleonic naval game called Don't Give Up The Ship! Both games had a mechanic that allowed for ships to take multiple hits before being sunk, which they'd borrowed from the wargaming rules designed by author Fletcher Pratt in the 1930s. They borrowed those rules again for D&D.

In his book about the history of simulation games Playing At The World, Jon Peterson explains why hit points were such an important idea: Hit points introduce uncertainty and variance [ ] In Dungeons & Dragons, even when the prospects of a hit are near certain, the damage dice provide another potential survival mechanism via endurance, another way of forestalling death and increasing the drama of combat.

From table to screen

Like D&D, video game combat discovered a new sense of drama with hit points. Early arcade games like 1978 s Space Invaders typically killed players with a single successful enemy contact, using multiple lives to prolong the experience. Replacing that with the ability to survive a set number of hits before dying added a finer-grained rise in tension. It removes the frustration of being reset to the start of a level every time a player is so much as brushed by an enemy, and as the number of hit points remaining falls your anxiety rises in direct correlation.

Being on your last life may make you cautious, but there's a smoother transition with hit points. You gradually shift between playing more carefully as you approach half-health, biting your metaphorical nails as it dwindles below that, and sinking into erratic risk-taking when only a sliver of life remains.

Video games inspired by D&D were the first to copy hit points, as far back as 1975 games PEDIT5 and DND, which were coded for the PLATO system designed by the University of Illinois. DND was also the first game to have bosses, who could have hundreds or even thousands of what it called Hits.

The first official adaptations of D&D to PC were the Gold Box series begun by SSI with 1988 s Pool of Radiance. They followed the rules of what was then called Advanced Dungeons & Dragons closely, which meant beginning characters had very few hit points. Playing around a table there s always the option to fudge dice rolls to prevent deaths from feeling too arbitrary, but the computer was never so forgiving and players got used to reloading frequently.

Games that weren t licenced had no such problem. The first Ultima began players with a tidy 150 hit points, and the second with 400. Important non-player characters like Lord British had totals so high that killing him became seen as a challenge, and by Ultima III players were luring Lord British to the beach so they could attack him with cannon-fire, as if he was one of the naval ships in the wargames hit points came from.

Arcade games tended not to represent hit points numerically, however. Memorably, in the platformer Ghosts 'N Goblins (ported to the Commodore 64 in 1986) Sir Arthur lost his armor on taking damage, continuing to fight in his underwear.

One of the first game to represent hit points with the now familiar life bar was Dragon Buster, a 1985 dungeon crawler by Namco with a Vitality meter that changed from blue to red as you took damage from its bats, snakes, and cave sharks. While red life bars would go on to become standard, other ways of visualizing hit points have been tried with varying degrees of success.

1983 ZX Spectrum/BBC Micro game Atic Atac had a slowly depleting roast chicken that tracked your starvation, and dinosaur fighter Primal Rage used veins leading to a heart that exploded at the moment of defeat.

Other games have tried to make their life bar a part of the game world, as in first-person Jurassic Park game Trespasser where it's a heart tattoo on the protagonist's breast you have to look down at to check. In sci-fi horror game Dead Space the life bar is represented by lights on the back of your armor, which would be very useful if you had a doctor standing directly behind you. Each of these visualizations is just a way of integrating a hit-point counter into the world, but in doing so they free the player from having to correlate a number with something that should feel real and immediate. They re all still the same old hit points, under the surface.

MIDI Maze, a 1987 first-person shooter on the Atari ST, was an early example of both the deathmatch shooter and the idea of representing hit points visually. Each player was a floating smiley face, like a three-dimensional Pac-Man, and an icon of that face at the top of the screen became sadder as they took damage. Later shooters like Wolfenstein 3D and Doom would copy this idea, their protagonists' faces growing more bruised and bloody as they absorbed bullet after bullet.

On the next page: hit points through the 90s and 2000s with regenerating health and more twists from their D&D origins.

The regeneration generation

MIDI Maze is an early example of another change in the way hit points worked, as it also had regenerating health. It wasn't the first, however. The action-RPG Hydlide, released on Japanese home computers like the PC-88 in 1984, gave players back hit points when they stood still. Where other games had food and first-aid kits that functioned as magically as the healing potions in fantasy RPGs, regenerating health though no more realistic at least took health items out of the game world. It made healing an abstraction like hit points are, rather than requiring players assume Johnny Medkit has wandered the world ahead of them scattering healing items like seeds.

It was Halo: Combat Evolved that popularized regenerating health, which is ironic because it didn't really have it. Halo's hero Master Chief wears an energy shield that regenerates after a short interval without taking damage, but once that's gone he has a traditional life bar that can only be refilled with medkits.

However, the recharging energy shield was what gave Halo its famous 30 seconds of fun that happened over and over and over and over again as designer Jaime Griesemer put it, letting players pop out of cover to shoot aliens and then duck back to recharge and reload, and that's what had a lasting impact.

The idea was copied and modified by plenty of other games. Call Of Duty has become the flag-bearer for regenerating health, taking the blame for its propagation though it wasn't introduced until the second game in the series. Even in the mid-2000s as it was first becoming widespread, regenerating health was criticized by old-school shooter fans for removing some of the drama and tension that hit points represent. It's still enraging comment sections today.

Three games released in 2005 and 2006 all tinkered with ways of making regenerating health retain the sense of rising tension that hit points were first introduced to create. Condemned: Criminal Origins, Prey, and F.E.A.R. all set a floor on automatic healing so that if you take enough damage to fall below around 25% of your hit points you can't regenerate back above that line. It models a difference between taking a serious wound and the kind of graze action heroes can just walk off, and adds grit to more serious games.

When the Just Cause games toy with this, only letting you regenerate a percentage of the most recent damage you take, it can seem at odds with their over-the-top action.

Horror games have also tweaked the way they use hit points to suit the genre. Zombie game Left 4 Dead slows you down the more you're hurt, making it harder to run away from the infected as if you're a movie character being worn down by the chase. In Silent Hill 4: The Room you regain health in your apartment, but when that safe space becomes tainted it stops healing you, a mechanical sign of its corruption that ensures you feel the same dread the character would.

Back to the source

Still, across all of these games, what hit points represent isn't entirely clear. Are they purely the injuries you endure, as the suffering face of Doomguy suggests? If that's true why is it so easy to get hit points back, whether through healing items or regeneration or drinking Fallout's irradiated toilet water?

In The Lord of the Rings Online hit points are replaced by morale, which explains why singing a jaunty tune helps top it up. In the Assassin's Creed games it's synchronization, a representation of how accurately your digital simulation is recreating historical events although that raises the question of why being hurt during events where your historical analogue was also hurt doesn't improve synchronization.

Even in D&D it's unclear what hit points really are. In the Dungeon Master's Guide for Advanced Dungeons & Dragons 1st Edition, Gary Gygax wrote that hit points reflect both the actual physical ability of the character to withstand damage as indicated by constitution bonuses and a commensurate increase in such areas as skill in combat and similar life-or-death situations, the sixth sense which warns the individual of some otherwise unforeseen events, sheer luck, and the fantastic provisions of magical protections and/or divine protection.

(Charmingly, the rules then went on to explain that Rasputin would have been able to survive for so long because he had more than 14 hit points. )

Constitution, skill, sixth sense, luck, magic, and divine protection are a lot of things to bundle into one number, and raise further questions about why, for instance, poisoned attacks cause extra damage to your “sixth sense”. When asked about what hit points really are at conventions Gygax was dismissive, giving different answers to the question each time. Sometimes he said hit points represent the way swashbuckling movie heroes survive so many fights, or that they were an entirely meaningless number that represented nothing more than a way of making the game's combat more enjoyable for players. 

That second answer is perhaps the best explanation. Given that hit points started out as a way of simulating the ability of a ship's hull to weather cannon-fire, it's only natural that there's going to be some vagueness and necessary abstraction when we apply that same concept to our video game heroes. They may as well be health pineapples, after all.

This feature was originally published in August 2016.

The original Quake was a muddy medieval world of knights, Lovecraftian horrors, and grim castles. But the sequel, cleverly titled Quake II, goes in a different direction entirely. You re a space marine, naturally, who has crash-landed on an alien world called Stroggos. In a desperate attempt to prevent an invasion, Earth sent an army to the distant planet, but the Strogg knew you were coming and your arrival was a slaughter. The dropships were shot down by anti-air defences and pretty much everyone died, except you. And so, in true id Software FPS style, it becomes a solo mission.

There s a chance you don t remember any of that. After all, Quake II is not a game renowned for its deep, complex sci-fi storyline. But the inclusion of a plot, and mission objectives, was pretty unique for an FPS in the late 90s. As you play, a robotic voice regularly drones computer updated and gives you mission objectives. By modern standards that s completely unexciting, but back then it set Quake II apart from id s other shooters. It was more cinematic, and your actions felt somehow more meaningful. And by your actions I mean shooting , because that s the beating heart of the game. Shooting things, and avoiding being shot.

At the time, Quake II was a technical marvel. Powered by the id Tech 2 engine, it boasted features that seem unremarkable now, but were amazing in their day. Hardware-accelerated graphics, coloured lighting, skyboxes, and the ability to return to previously completed levels were among its once groundbreaking features. After the release of Quake II, the engine powered several other games, including, in the early stages of its development, Half-Life. Quake II also had massively improved networking, making it one of the best early examples of an online FPS. Mod support also dramatically extended its lifespan for anyone lucky enough to have an internet connection with which to download the things.

People are still making mods today, in fact, including a few that let you play the game at high resolutions and with some graphical improvements. It ll still look like a game from 1997, but it makes it a bit more tolerable to modern eyes. Character movement is mapped to the arrow keys by default, but after some rebinding you can have it playing like a modern FPS. Although, weirdly, strafing is faster than moving forward and backwards. A strange sensation that took me a while to get used to. But for such an old game, Quake II is surprisingly playable.

A big part of this is its arsenal. It s still one of the finest collections of FPS guns on PC, and every weapon you wield has a distinct personality. The chaingun rattles at incredible speeds, getting steadily faster the longer you fire it. The super shotgun is like a handheld anti-aircraft gun, and you can almost feel the power as you unload it into an enemy and hear that echoing boom. The exaggerated kickback on the machine gun, which rises slowly as you fire, gives it a sense of physicality. And I love it when you fire the grenade launcher and hear the metal clink of the grenades as they bounce around the level. Every weapon, except maybe the blaster, is a joy to fire.

But the best of the lot is the railgun. This metal tube of death fires depleted uranium slugs at extremely high velocities, which leave a blue corkscrew of smoke in their wake. The railgun is incredibly accurate it s like a sniper rifle without a scope and it can cut through several Strogg at a time. In fights with multiple enemies, a useful strategy is running around until a few of them are lined up, then firing a slug. Seeing it tear through a line of bad guys is one of the greatest pleasures in first-person shooting.

And the things you shoot are just as well-designed. Quake II has the standard FPS structure of starting you out against small groups of easily-killed grunts, increasing the challenge the deeper into the game you get. In the first few levels you re fighting shotgun-toting Guards, beefy Enforcers with chainguns, and Berserkers who lunge at you with big metal spikes and later fire rockets at you. The way enemies explode into chunks of bloody meat, or gibs to use the parlance of the times, is still gruesomely satisfying. And there are other grisly touches, like when you don t quite kill an enemy and they squeeze off a few extra shots before they finally collapse and die.

But this is just to ease you in, and it s not long before id starts throwing its meanest creations at you in force. The Strogg are weird cyborg hybrids, with mechanical limbs and eerily human, grimacing faces. Gladiators stomp around on metal legs, firing their own version of the railgun at you. Mutants are angry, feral beasts who pounce on you, usually from dark corners. Brains, perhaps the weirdest enemy, attack you with tentacles and blood-stained hooked hands. There s a huge variety of things to kill, all with unique behaviours and weapons, which keeps the game interesting especially when you re facing several types at once.

The hardest thing to stomach when revisiting Quake II is how brown it is. The switch from dark fantasy to sci-fi leaves the levels brutal, industrial, and metallic. There isn t much variety or detail in the environments, and the colour palette is depressingly muted. The actual design of the levels is great, with plenty of secret areas and multi-level arenas to fight in, but the lack of colour and almost nonexistent world-building make it feel like a bit of a slog at times. But I remember thinking this back in 1997, and really it s a game about combat, not drawing you into its world. And since the Strogg live only for war, I guess it makes sense that their planet would be like one giant factory.

When you ve fought your way through the Strogg and infiltrated the headquarters of their leader a space station in an asteroid belt above the planet it s time to complete your final objective: kill it. The Strogg leader is called The Makron, and it s a two-stage boss fight. Its first form is a powerful exoskeleton which comes equipped with a BFG10K, the most powerful weapon in the game. And, unlike your own BFG, it can fire it multiple times in quick succession. When you destroy the mech, it s time to kill The Makron itself, which also has a BFG as well as a blaster and a railgun. Luckily the arena is littered with power-ups, health, and ammo, including a secret underground chamber that can be accessed by pressing a hidden switch. When the boss falls, you step into an escape pod, and that s it. The End unceremoniously flashes up on the screen, and your only choice is to go back to the menu. Imagine if a game ended like that today.

Quake II is still a great game, and I m surprised by how well it holds up. There s something about the feel of the weapons, the way they re animated and how they sound, that makes them some of the best examples in the genre. Even the new Doom, which is a fantastic ode to this era of shooter design, doesn t have anything quite as enjoyably punchy as Quake s railgun.

WASD feels inevitable today. Once mouselook became standard in 3D games, it made little sense (at least for right-handed players) to hold your left arm across your chest to reach the arrow keys. The WASD keys were more comfortable, and offered easy access to Shift and Space. But even though WASD seems like the obvious choice now, far fewer players used it 20 years ago.

Our favorite four letter word was never a foregone conclusion, and didn't become standard through some gaseous enlightening that spread to every PC gamer simultaneously. The new movement scheme took several years to catch on, and while we can t know whose fingers found their way to WASD first, we do have a good idea of who popularized the style: the greatest Quake player in the universe, Dennis Thresh Fong.

Fong made history when he took home John Carmack's Ferrari 328 after winning the first-ever nationwide Quake tournament in 1997. And when he won that tournament, defeating Tom "Entropy" Kimzey on Castle of the Damned, his right hand was on a mouse, and his left hand was perched over the four keys we now consider synonymous with PC gaming. But even then, not everyone played that way.

In the early days of first-person shooters, Fong says the keymappings were all over the place, and even the great Thresh had only just started to play with a mouse at all. Imagine him just a few years before, sometime around 1993, as a teenager losing a match of Doom against his brother Lyle. Like many Doom players, Fong used only the keyboard. Without the need to look up or down, it was a natural choice so much that using a mouse was even considered weird. His brother, however, was playing with a keyboard and trackball, and he was winning. It wasn t every game both were excellent players but Lyle won enough that one summer Fong decided he had to learn to play with a mouse. After that, he was unbeatable.

Right after I made that switch, my skill improved exponentially, says Fong. Pretty much, from then on, I never lost.

It took some experimentation including a strange attempt to move with WADX but Fong settled on WASD and has been using it since Doom. Did he invent the scheme? No, probably not. Others were also gravitating to the left side of the keyboard for Doom at the same time. But without Fong's influence, the default could have ended up different. It might have been EDSF, or stranger configurations like ZXC to strafe and move backwards, and the right mouse button to move forwards. Some early shooters bound movement to the arrow keys. In 1994, System Shock used ASDX, while Descent used AZ for forward/reverse and QE for banking (if you didn't happen to have a joystick).

Fong tells us he even knew a player who used ZXCV to move.

I m certainly not going to take credit for the creation of [WASD], says Fong. I stumbled across it. I m sure other people started using it as well just based on what was comfortable for them. I definitely think I helped popularize it with a certain set of gamers, particularly the ones that played first person shooters."

It s likely that he did. The very concept of a professional gamer was new at the time, and Fong was well-known on the west coast as the best player around. As Fong s celebrity grew, the one question everyone asked him was: What s your config? His answer could be most readily found in Thresh s Quake Bible, which describes the WASD formation as an inverted T. And his guide carried weight. Even before his success as a Quake player, Fong was a Doom champion, and so people imitated him, just as the kids at the basketball court by my house spend far too much time trying to hit Steph Curry s 30-foot shots.

The evidence can be found on old bulletin board systems. In one thread from 1997, a poster recommends using Q and E to strafe and A and D to turn. Another suggests using the keypad for movement, and someone else says they use A, Shift, Z, X. It wasn't the case that everyone simply gravitated to the 'obvious' choice of WASD or ESDF, and in another thread, we see how Thresh's performance in the Quake tournament spread his style. His play was so impressive, the poster looking for his config speculates that it was impossible for him to turn so fast with a mouse.

Another legend, Quake programmer John Carmack, took note. Even when I was hanging out with Carmack, wherever, at E3, random people would come up and he would hear them asking me what my configuration was, says Fong. So he ended up building a Thresh stock config into Quake 2.

It was a relief. Not only could Fong sit down at any computer with Quake 2 and instantly load his configuration, every time he got the question, all he had to say was type exec thresh.cfg.

Convenient as it was, Fong doesn t think the inclusion of his config was the main factor in the rise of WASD, and I d agree. By the time Quake 2 was out, WASD was starting to feel like common knowledge. I used it, and I don t remember hearing Thresh s name associated with it at the time, though it s possible his configuration entered my consciousness two or three people removed.

And yet games, strangely, took a while to catch up. Carmack may have bundled Thresh s config with Quake 2, but when it released in 1997 the default controls were still arrow keys. A year later, though, that changed. If Thresh's Quake tournament win was WASD's first watershed moment, the second came in 1998 with the release of Half-Life. The Quake and Doom players at Valve perhaps influenced directly or indirectly by Carmack, Thresh, and other top Doom and Quake players included WASD in Half-Life s default keyboard and mouse config, which helped solidify it as the first-person shooter standard.

Valve engineer Yahn Bernier checked Half-Life's original config file for us and confirmed it included WASD. "I remember finalizing this file (maybe with Steve Bond) during the lead up to shipping HL1 but don t recall specifics about when WASD was settled on or really why. We probably carried it forward from Quake1 " he wrote in an email.

The same year, and less than a month after Half-Life, Starsiege Tribes also made WASD default. Quake 3 followed suit in 1999, and WASD's popularity grew even more. It was also the default binding in 2000's Daikatana, but Half-Life, Tribes, and Quake 3 probably had a bit more to do with its popularity.

There were still plenty of heretical control schemes in 1999 like System Shock 2's, which defaulted to WADX (and S for crouch). But WASD had momentum. If it wasn t already ubiquitous by 2004, World of Warcraft defaulting to WASD codified it for millions of PC gamers. Now it s in RPGs and MOBAs and even strategy games, controlling camera movement over maps.

Interestingly, Valve boss Gabe Newell doesn t use WASD. I personally don't like WASD as it takes your hand away from your typing home keys, he wrote in an email to PC Gamer. I always rebind to ESDF. Newell's not alone there. Do a little Googling and you'll find plenty of people arguing that ESDF is the more natural configuration.

More surprisingly, another Half-Life developer, level designer Dario Casali, also rejects WASD. Instead, he prefers ASXC. It feels natural to me, where WASD feels odd, wrote Casali. But lots of people scoff at my config.

What would PC gaming be like had EDSF or ASXC been Half-Life s default? No offense intended to Newell or Casali, but I shudder to think of it. ASXC just sounds bonkers to me. Newell's fairly commonplace ESDF is more palatable, but as Thresh echoes, it feels harder to hit Shift and Control while easier to mispress one of the surrounding keys. For me, Thresh, and millions of PC gamers, it s WASD for life.

You can read more about the history of Quake in our retrospective celebrating Quake's 20th anniversary. We're also celebrating by running a Quake server through the weekend, and Thresh himself will be playing on our US-West server today, Friday, from 3:30 pm - 4:30 pm Pacific time.

Wes Fenlon also contributed to this article.