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.

"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." D&D co-creator Dave Arneson

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.

Regenerating health was criticized for removing the drama and tension that hit points represent.

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.

No one wants to end up in jail, but there’s something fascinating about life in the clink. There have been some great fictional prisons in literature and cinema—and video games too. The following hoosegows are some of the toughest, most brutal, and hardest to escape from in gaming. Some horrible prisons, both new and old, have made their way onto this list since we first wrote it.

From freezing Russian labor camps to max security space-jails, these are scariest imaginary prisons on PC.

B.J. Blazkowicz had to shoot an awful lot of Nazis to escape from the labyrinthine Castle Wolfenstein. As prisons go, Wolfenstein does offer some perks: ample access to weaponry, secret Nazi treasure, and delicious, hearty meals. On the downside, the dogs aren't very friendly and there's a giant Nazi with two machine guns standing between you and the exit. If you take too many bullets, you'll have to resort to eating dog food. Yuck.

Batman famously has one of the best rogue's galleries in comics, and his nemeses inevitably end up in Arkham, Gotham's prison for the criminally insane. 2009's brilliant Arkham Asylum makes the prison itself the star, imagining it as a densely interconnected 3D playground in the vein of Super Metroid. As Batman gains new bits of equipment he opens up new ways to explore and unlocks new shortcuts. In the end, Arkham Aslyum has some great depictions of Batman's villains and the dark knight's abilities, but mastering the asylum is the true joy.

The Souls series has some of the toughest prisons in gaming. Dark Souls starts you off in one, the Undead Asylum, which is guarded by an overweight demon that ruins newcomers on the reg. Dark Souls 2 has the Lost Bastille, a prison made entirely of cold grey stone, patrolled by undead knights and exploding mummies, and wraps with a boss battle against three nimble suits of armor. But Dark Souls 3’s Irithyll Dungeon is the prison-iest of all (most prison-y?). It glows a sickly green and greets you with the Jailers, spooky robed guards that lower your max health just by looking your way. Explore the cells and eventually you’ll run into the wretches, grotesque human-dragon hybrids, botched experiments of the Lothric family. Deeper in you’ll find giants taken prisoner, massive sewer rats looking for a snack, a downright mean basilisk ambush, some items that sound off a large scream when picked up to alert nearby enemies, a gluttonous humanoid with an enlarged hand for a head called—what else—the Monstrosity of Sin, and some sewer centipedes. Don't Google them.

It’s an awful place that folds over on itself in a disorienting search for one key after another, delaying your escape just beyond its rows and rows of thick iron bars. Get in, save Siegward, and never return. 

Protagonist Vito Scaletta gets busted for selling stolen ration stamps and ends up in the clink. This is an act break of sorts, separating the game’s 1940s and 1950s chapters. The slow walk through the gates, being yelled at by jeering prisoners, is straight out of The Shawshank Redemption. You pass the time by punching people and scrubbing toilets, before emerging into a terrifying world of quiffs and rock and roll.

JC Denton defects from UNATCO and becomes a wanted man. He’s captured and wakes up in a mysterious underground cell. With the help of a creepy AI calling itself Daedalus he manages to escape, only to discover that the sinister prison facility is located below UNATCO’s Liberty Island headquarters. Most people who mess with Majestic 12 end up dead, but JC uses his nano-powers to break out and flee to Hong Kong.

Butcher Bay is a space-prison for the galaxy’s toughest, gruffest space-bastards. Escape From Butcher Bay sees the titular Riddick, played by Vin Diesel, breaking out of this maximum security sci-fi prison by stabbing, choking, shooting, and sneaking past its small army of guards. But, even though escape is his top priority, he still finds the time to enter bare-knuckle boxing matches and shiv other prisoners.

“It used to be a high security prison,” says Alyx Vance, gravely. “It’s something much worse now.” She always was good at introductions. Nova Prospekt is an old prison that the Combine have converted into a facility for processing any ‘anti-citizen’ who fights against their tyranny. ‘Processing’ meaning being turned into a hideous half-machine monster. A grim place indeed, but no match for Gordon’s gravity gun.

The Suffering is a mostly forgotten 2004 shooter from Midway, set on the twisted Carnate Island off the coast of Maryland. The penitentiary itself, where you're on death row, is just the beginning—the whole island has a dark history, including an insane asylum and a whole lot of executions. Hell breaks loose immediately when an earthquake calls up hordes of twisted monsters, who proceed to wreak havoc on the prison. It all may sound like standard horror fare, but The Suffering stood out thanks to some fabulously creepy designs by Stan Winston Studios. Those are monsters we would not like to be trapped on an island with.

Probably the toughest prison on the list, Vorkuta is grim Russian labour camp and one of the most memorable levels in Black Ops. With help from Viktor ‘Gary Oldman’ Reznov, your fellow prisoners, a mini-gun called the Death Machine, and giant slingshots loaded with explosives you battle to freedom and destroy half the prison for good measure. Shame about that rubbish vehicle section at the end.

The prison ship Purgatory, operated by the Blue Suns mercenary company, is where unstable biotic Jack finds herself. Commander Shepard, hunting for the galaxy’s baddest asses, flies there in order to recruit her. Before it was a prison, the ship was used to transport animals, which explains the tiny cages masquerading as cells. It’s not all bad, though: if it gets crowded, the Blue Suns will dump you on a nearby planet.

This desert prison used to be a peaceful coal mining town, but now it’s a hellish jail. Cloud and co. are dumped here after a misunderstanding, and have to earn their freedom by entering, and winning, a chocobo race in the Golden Saucer theme park that looms over the prison. As far as I know, this is the only time in gaming history where you escape from jail by riding a giant chicken. Hopefully it’s not the last.

That’s not a very nice name. Why not Warmridge Prison? Dishonored protagonist Corvo Attano is sent here after being wrongly accused of murdering the Empress he was charged to protect. It’s an imposing building—designed by the same guy who dreamed up Nova Prospekt, Viktor Antonov—and serves as the game’s tutorial. Murderous inmates, brutal guards, and rats are among this foul place’s residents.

This Alaskan military base isn’t technically a prison, but Solid Snake finds himself imprisoned in a cell there during the first MGS. There are a few ways to escape, but my favourite is spilling a bottle of ketchup and lying down next to it. The idiot guard thinks you’ve killed yourself and rushes in to help, giving you a window to break out.

Only slightly harder to endure than listening to the band Bastille, this famous French prison was notorious for its brutal treatment of prisoners. It’s here that the foppish hero Arno Dorian learns how to fight, and ultimately becomes an assassin. After the French Revolution it was demolished and replaced with a monument, but it will live forever in the decidedly average Assassin’s Creed Unity. C’est la vie.

Hell's Prison, posted on Reddit, is just one of thousands of devious, depressing prisons concocted by Prison Architect players. There's probably a harsher prison lurking on a hard drive somewhere, but Hell's Prison is a good example of how totalitarian Prison Architect lets you be as a warden. 

"At any given time about 90-100 prisoners are in the initial stages of starvation and taking damage," reads the description. "The entire prison is one giant infirmary so that doctors automatically tend to them. Prisoners who are close to death are brought to the medical beds by the guards. I have yet to lose a prisoner to starvation."

Prison Architect's Steam Workshop is also full of fantastic creations and recreations, like Alcatraz. Now that's a tough prison.

One of the most famous video game prisons, this is where you start your adventure in Oblivion. You don’t know what your crime was or how you ended up there—you’re supposed to fill in the blanks—but a fateful encounter with the Emperor of Tamriel leads to your escape and transformation into a hero. You can return later and take the opportunity to teach gobshite Valen Dreth some manners.

There are a number of ongoing efforts to mod older games into newer engines. Black Mesa, for instance, rebuilt much of the original Half-Life in the Source Engine, and the modders behind Skywind are painstakingly crafting Morrowind in Skyrim's Creation Engine. With Doom Reborn, modders have been working diligently to recreate Doom and Doom II in Doom 3's idTech4 engine. They recently released a pre-beta version, so I thought it was a good time to see how the first FPS I ever played looked with a facelift.

Memmories... like a goon-filled poison piiiiit...

Doom II represented a number of firsts for me. It was the first FPS game I ever played (I played Doom II before I played the original Doom). It was the first game I needed to create a boot disk for, just so I could run it on whatever toaster I was using as a PC back then. It was the first multiplayer game I ever played, and I recall an evening spent talking to my friend Mark on the phone, then taking the line from the phone and plugging it into my modem, then dialing up Mark, not getting a response from his modem, then replugging the line into the phone to call him again to troubleshoot (we eventually got it working, had a complete blast, then plugged our lines back into the phones so we could talk about it afterwards).

The Marine needs no colored keys for these doors.

It may seem a bit dubious to rebuild a classic FPS -- the classic FPS -- in an engine that doesn't look particularly pretty these days (I think Source has aged much better than idTech4, probably because Source has been continually refined over the years), but I'm impressed at how comfortable and familiar the mod feels. The levels are immediately recognizable as the layouts are identical: I enter Doom II, immediately turn around, run around the corner to the right, and collect the chainsaw without even thinking about it, even though it's probably been fifteen years since I've actually done that.

Back in the day, we liked our buttons big. Really big.

In fact, while running and gunning through the rebuilt levels, I found all sorts of ancient muscle-memories kicking in. I'd stop and stare at a wall, or hesitate in front of an alcove, or gaze across a bridge, knowing there was something to be done but not quite remembering exactly what. I think it's a pretty good indicator that the levels have been rebuilt faithfully if, even in a different game engine, long-dormant triggers are still firing in my brain.

Huh. I am strangely compelled to stand in this alcove. But WHY?

As for the gameplay itself, I expected it to feel slow and sluggish when compared with the original. And it definitely is a bit slower: guns seem to take too long to reload, enemies seem to take a while to react. After a couple levels, though, it starts feeling more natural, more slick, more in keeping with the breakneck pace and corridor-gliding action of the original game. It's not as fast or smooth as it was back then, no, but on the other hand, neither am I.

No AI misfires here. They seem quite aware of me.

You may have seen the gameplay video which shows the enemy AI, in some cases, completely absent, but in this pre-beta a lot of that seems to have been fixed. I didn't really encounter any brain-dead enemies. Sure, most of them weren't exactly brilliant, but no one just stood there helplessly watching while I killed them. And, nicely, one of the most entertaining bits of the original Doom games is still there: enemies accidentally hitting each other and then fighting each other to the death while you watch. I don't know if that happened in Doom 3 (probably) or if the modders had to code it themselves, but who cares? Monsters killing each other means I can save a little ammo here and there.

You two let me know when you've sorted this out.

The mod is still in progress, so not all the levels from the original games are present, though I was happy to find the secret Doom II Wolfenstein level in there. What can I say, it's fun killing monsters in front of Hitler portraits for some reason.

Sorry to break up your shotgun shell organizing party.

I'm sure this mod isn't for everybody, but I think that can be said for any mod of this nature. People who love Doom from the old days will probably still prefer to play the original games. That's how I felt about Black Mesa: while I enjoyed it and was impressed at all the work involved, it never quite clicked for me. When I want a nostalgia trip, I'd prefer full-fare. Doom Reborn is still worth checking out, though, and I enjoyed it (more than I actually enjoyed Doom 3, even).

All these years later, that's still a good indication of a button you shouldn't press.

Installation: What's the best kind of installation? Self-installation! Just download the pre-beta (what is a pre-beta, anyway, if not an alpha?). When prompted, just point it at your Doom 3 folder. Piece of cake.

Nothing warms my cold cynical heart like the creativity of the Doom modding community. We saw Donkey Kong Country recreated in the engine earlier this week, but now cast your eyes across this work-in-progress attempt to adapt DayZ's core gameplay into a 20-year old engine. DoomZ is the work of a modder disenchanted with the limitations of DayZ in its current, Enfusion-powered iteration. While Zdoom obviously has limitations of its own, it looks like the mod is making steady progress.

The mod currently boasts a day and night cycle, a rather charming UI (see the image above), wildlife, fires and cooking, water, weapons, food, limb damage and much, much more. The goal is to make the game as close to the DayZ gameplay model as possible, though given the engine's limitations there won't be vehicles. Creator Robert Prest writes that the mod could move over to GZdoom, allowing for more flexibility in map design.

As for the video below, Prest provides pretty good commentary on what the project is now and where it's headed. Alpha 11 can be downloaded right now. Cheers to Kotaku for the heads up.

Sometimes, the only way to attract attention to dire warnings about weaknesses in a particular system is to exploit them in a way that can't be ignored. That's what drove Michael Jordon of Context Information Security to make Doom run on a Canon Pixma printer; not because it's cool (although it clearly is) but to demonstrate the inherent insecurities in Canon's wireless printers.

The colors in the brief gameplay video posted by YouTube user SteveHOCP are wonky (and the music has obviously been added after the fact), but there's no question about it: This is Doom, id Software's greatest creation, running on a printer. It's a remarkable demonstration of how far technology has come over the past two decades, but the actual point was to demonstrate something else entirely: The web interface on Pixma wireless printers doesn't require user authentication in order to connect, which doesn't seem all that particularly terrible until you start looking at the firmware update process.

"While you can trigger a firmware update you can also change the web proxy settings and the DNS server. If you can change these then you can redirect where the printer goes to check for a new firmware," Jordon wrote. "So what protection does Canon use to prevent a malicious person from providing a malicious firmware? In a nutshell - nothing, there is no signing (the correct way to do it) but it does have very weak encryption."

Things get awfully technical at that point but the condensed version is that a determined individual could create a custom firmware and update a printer to make it do pretty much anything within the capabilities of the hardware. "For demonstration purposes I decided to get Doom running on the printer," he wrote. "It was not straightforward due to it needing all the operating system dependences to be implemented in Arm without access to a debugger, or even multiplication or division." But it was doable.

"If you can run Doom on a printer, you can do a lot more nasty things," Jordon told the Guardian. "In a corporate environment, it would be a good place to be. Who suspects printers?"

Canon said in a statement that it intends to issue a fix "as quickly as is feasible."

People are still doing insane stuff with the Doom engine, and nowhere is this better demonstrated than with this Donkey Kong mod. The GZDoom mod turns Doom into a whimsical side scrolling platformer, which is obviously quite a change from its origins as a brutal first-person shooter. To give it a go you ll need GZDoom, a download of the mod as well as one of original Doom engine .WADs.

Unless you're intimate with the Doom engine and its modding community, the video below will probably be a bit confusing: how (and I suppose more importantly, why) does one turn a first-person shooter into a sidescrolling platformer? Um, I have no idea, but there's an eerie pleasure in watching a version of Donkey Kong played out with the occasional appearance of old Doom assets. The instructions for installing the mod are over here in the video description.

In other Doom mod news, this is quite impressive.