Normally in a Video Game, if your Hit Points bottom out at zero then Critical Existence Failure kicks in immediately: Game Over, man, try again. But in some games, the hit that reduced your HP to zero isn't allowed to be the one that actually knocks you out: The first time you take fatal damage, your character is allowed to remain standing (with just a tiny sliver left on their Life Meter, e.g. 1 HP) and keep fighting... but only this once; taking any more hits in this condition (even Scratch Damage) will be obviously fatal.
This can occasionally be Hand Waved if the character has multiple layers of Hit Pointswith different explanations, such as a character with a "Shield" or "Armor" meter where one layer must be fully depleted before the next layer is allowed to take damage.
On the bright side, this is an excellent opportunity to unleash a Desperation Attack of the highest order, but unless you're prepared to subsequently end the fight with a Finishing Move, improvise a No Damage Run (if possible) or have some way to quickly get out of dodge and Heal Thyself, the risk of imminent Critical Existence Failure is a dire one to weigh; exploit this at your own risk.
Sometimes, a game may place restrictions on when characters are allowed to have a Last Chance Hit Point, like requiring the character to be in good health before taking the fatal blow, or requiring that the attack would have inflicted massive damage (e.g. a One-Hit Kill) to begin with. Without these restrictions, this could lead to Game Breaker situations where a character who can perform even trivial healing becomes Nigh Invulnerable since they don't remain on their last hit point long enough to take a second (fatal) hit. In action-based genres, Combos can sometimes bypass this, depending on whether the ability triggers based on individual hits or the attack chain as a whole.
Note that this trope only applies to cases where a character endures an otherwise lethal amount of damage without a knockout. If an attack happens to leave the player at 1 HP by exact count (say, they have 50 HP and a given attack inflicted 49 points), that's just luck, not an example.
Games featuring a One-Hit-Point Wonder are exempt from this trope as a rule, as any damage results in the loss of one life (and/or current Power-Up).
In RPGs, this may be one of the effects of the Luck Stat. From an In-Universe standpoint, this may be the result of the character's Heroic Willpower.
Compare Heroic Second Wind, which is this as a plot device not a game mechanic.
Contrast Auto-Revive, a similar effect which occurs after the knockout blow instead of before it — meaning that any effects which reset upon KO (Status Buffs, etc.) are lost, whereas with a last chance hit point those effects are still active.
See also HP to One, an enemy attack specifically designed to reduce the player to their last Hit Point regardless of their current HP.
In Dissidia: Final Fantasy, characters can purchase and equip accessories that provides different variations of this effect.
Phoenix Downs and Phoenix Pinionsnote as well as their Duodecim counterparts, Iifa Leaf and Iifa Dew, respectively, are the most straightforward examples, which allow you to survive a killing blow with 1 HP or convert your bravery into HP respectively. Breaks upon use.
Final Position and Final Decision are this when it comes to brave attacks, with the former preventing break status from one attack while the latter has this for one combo.
The "Morale" Status in Epic Battle Fantasy 4 does this as long as the character has it. However, they must have at least 50% of their max health before the lethal hit for it to work. Useful against the Glitch, whose attack is an otherwise unavoidable, unblockable One-Hit Kill.
This can be seen with certain Giant Flyer monsters in Final Fantasy X, who start out flying but are forced to land when their HP is too low. Even when your characters deal 5 9's of damage, the bird still goes through its landing animation with 1 HP left.
Final Fantasy XIII has the passive Sentinel ability Reprieve. If your Sentinel's HP is above 30%, taking a blow that would otherwise take him or her out will instead leave the victim with 1 HP.
In Gods Eater Burst, certain pieces of equipment have either the passive skill "Firm Stand" or "Prepared". The former ensures that you will always survive any attack with at least 1 HP if you have at least 51 HP remaining when you get hit (which would be 51% of your base HP), provided you successfully guard the hit, which requires that you have enough stamina remaining. The latter is similar, but has no HP threshold. You're far from invincible, but with "Expand Guard Area" (extends your guard area so that it surrounds you completely) and skills to minimize stamina usage from guarding attacks...
In Kingdom Hearts, Sora can learn "Second Chance" to provide this effect against single hits; the sequel added a complementary ability ("Once More") that worked on enemy Combos; equipping both at the same time could allow Sora to endure incredible amounts of damage before a KO.
Birth by Sleep includes both Second Chance and Once More (and they work just like in the previous games), but the Final and Bonus Bosses all have ways to get around it, either by using non-consecutive blows so quickly that they might as well be consecutive, or stunlocking you at 1HP until they can hit you with something else. Needless to say, they're some of the hardest bosses in KH history.
This happens for enemies in Mass Effect 2 - in some cases you can whittle down their health so far that their health bar completely disappears but their name still shows on the top of the screen, and they can fight on until you land one more shot (or they take any tiny amount of damage).
In Metroid: Other M, Bullet Time accompanies the warning that Samus's HP is now flickering between 0 and 1 and the next hit will be fatal. This doesn't protect Samus against combos, and it's not present on hard mode.
Megaman Volnutt from Mega Man Legends always has this ability built-in. Any hit that costs the rest of his energy will still allow him to get up and keep on fighting with his life gauge glowing red. In the first game though, the final hit also takes out his Life Shield, so you might not want to get whittled down all the way even though it lets you get the best mileage out of your Energy Canteen.
In Monster Hunter Freedom Unite, one can actually make certain armor sets with a skill called "Survival", which allows the player to survive any attack with 1 HP if they were above a certain percentage of health beforehand.
In No More Heroes 2: Desperate Struggle, Travis gains an ability where if you shake the crap out of the controllers while he's falling from a death blow, he may stop falling and survive with five hit points. He can do this a maximum of five times, but there are less chances to do it on harder bosses, and it will not work on attacks where he is not falling, i.e. he is knocked to the ground by the move, or he is in a battle with different mechanics from the norm.
In Star Ocean: The Second Story, a character has a chance of surviving any lethal attack with 1 HP left, directly correlated with their Guts rating. Higher the Guts, higher the chance of survival, but it can still occur even if the character's HP is already at 1. Can get ridiculous (but awesome) when an opponent manages to connect dozens of lethal attacks on a character in rapid succession, the character surviving all of them due to their Guts alone.
Some party members in Tales of Vesperia possess an ability that makes it so as long as they're in Overlimit, they'll always have one HP left no matter how much abuse they take.
In Xenoblade, the Unbeatable gem gives the user a chance to survive with one HP upon receiving a fatal blow, up to a 50% chance at most, depending on the gem's quality. This is made more useful by the fact that the gem can still work if the user is already at one HP, and that Shulk's visions of the future will warn whatever or not the gem is going to save its user.
Astro Boy: Omega Factor has this happen, but only on Easy mode. If Astro takes a hit that would drop him to 0 hit points, he stays alive with his health at exactly 1, and will only go down if he gets hit again before finding a health item. It comes across as an exceedingly overt shift in your favor since Astro starts with 30,000 hit points and everything deals damage in units of 100 or more, but you'll wish it still applied on Hard mode when the enemies start killing you in one or two hits.
God Hand gives you one last chance to fight back, just as long as you weren't hit by a lethal attack.
This is a normal mechanic in Bayonetta. Contrasting to the Devil May Cry and God Hand examples, no matter how powerful an attack is, no attack will kill you instantly (unless it's normally an instant kill or cutscene death), provided you have some health before entering critical mode.
This can be taken to Game Breaker levels, provided that you have the Star of Dineta equipped.
There is, however, one exception to that rule in Bayonetta: Father Rodin has a grab attack that reduces you to critical health no matter how much health you have left, and it kills you outright if you were below half health.
The Wii version of Punch Out allows the player to mildly recover if the character (Little Mac) is about to lose by KO or TKO during a fight. One of the Exhibition challenges actually require this to be done during the fight against Mr. Sandman in Title Defense.
Even if you're at zero health in Double Dragon, you won't actually die unless you're knocked down (unfortunately, this applies to the enemies as well.)
In Arcana Heart 3, if a single hit would kill you via Block Damage, you are instead left with 1 health left.
Most Capcom fighting games will occasionally allow players whose health meters are completely red to stay alive. (In the event that player were to win that round, the player won't receive any bonus points for leftover health.) The Street Fighter II games on Super NES have this, possibly due to rounding 1 of 176 hit points down to 0 of 88 pixels.
BioShock series: On easy and normal difficulties, any hit that would kill you instead reduces you to 1 HP, requiring another hit to kill you outright. In the sequel, getting dropped to 1 HP activates one second of invincibility.
In Borderlands, a severe hit that would otherwise kill you will often leave you standing with no shields and only a sliver of health. However, this only works if the damage isn't too much over your limit. A truly epic attack will still kill you in one hit.
Borderlands 2 has Axton and his Grit skill; every point put in it (up to 5 without other boosts) gives you a 4% chance to ignore otherwise lethal damage. And not only is the damage ignored, but you get half your health back!
Every character has a variation of this, but it's more noticeable on Salvador. So long as you're above 50% health, nothing can kill you in one hit, no matter the level. This is useful in UVHM, as you can make it so you can take a lot of punishment before dying. This is why the Complacent Gaming Syndrome of the game's community revolves around Life Drain weapons, specifically slag variants of the Rubi, while keeping max HP as low as possible. Life-draining weapons heal you for a percentage of the damage you deal, which can easily fill your HP bar above half provided it's low enough.
Call of Duty has the last stand perk, which has you on the ground, hardly able to move, with a pistol to defend yourself. You can also be revived if a team-mate happens to come across you.* Singularity uses the same mechanic as BioShock 2.
In the Dark Forces Saga games Jedi Outcast and Jedi Academy, you'll find yourself getting knocked down to precisely 00 shield and 01 health a lot more often than can be explained by coincidence.
In its original form, the Croc-O-Style item set in Team Fortress 2 would allow the Sniper wearing it to survive otherwise lethal headshots with exactly 1 HP. As long as he had more than 1 HP, that Sniper could never be killed by headshots and would always be knocked down to 1 HP. That bonus has since been removed, and traded for a bonus that is functionally identical, but only works against 'quickscopes,' the act of firing a headshot immediately after zooming in and not charging the damage meter.
In Blood deathmatch, a player taking mortal damage will sometimes be knocked to his knees instead of dying. If he presses the action key fast enough, he can get back up with a single health point.
Not long after Pv P was introduced into City of Heroes, a mechanic was added so that no single attack could kill a player (regardless of level difference) if they were at full health. This was done mainly to mitigate the Stalker's arguably One-Trick-Pony Assassin Strike ability and give their opponents a fighting chance, with the side effect that even a brand new character could survive in the highest level zones - provided they only got hit once. Useful if your mentor was suddenly out of sidekick range and everything turned purple.
This came back to annoy them when they introduced a power called Self Destruction, which dealt the maximum hp in damage to the character. Unfortunately, the one-hit code prevented characters who were at full health from dying. Doubly unfortunately, the power blew up the character who used it, leaving them unable to do anything until they went to the hospital (Paragon City's hospitals can fix anything), but as they were still alive, the "go to hospital" prompt didn't show up...
There are ways around this, however- a DOT that deals heavy upfront damage will leave you at one hit point, then kill you unless you heal immediately. Fire blasters are particularly good at this.
City of Heroes also handles Falling Damage like this. No matter how far you fall, it can never bring you below 1 hitpoint. Land next to some enemies, though...
In Guild Wars 2, everyone has this. If your character loses their last hitpoint, you'll go down into a "Survival Mode". The screen encourages you to "Fight to survive", and gives you the use of four skills unique to each class. If you kill an enemy, live long enough to use the Bandage skill to heal yourself back up, or get revived by another player, you can get back up without respawning. Even if you bleed out, you can choose not to respawn, and another player can still revive you. There are penalties for this, of course.
In League of Legends, the ultimate (Endless Rage) of the champion Tryndamere, the Barbarian King, makes him unable to have his health reduced below a single hitpoint for 6 seconds. This works in conjunction with his passive, which increases his attack damage for each percentage of his total health currently lost. This can allow him to annihilate teams when he's got some good items or escape.
In Mabinogi, there is a small chance that a lethal attack will send your health into negative values but not kill you, creating what is known as Deadly status. The Will attribute increases the chance of invoking this.
Additionally, any attack that does more than your total health while you have more than half of it left will automatically send you into deadly.
Also, Poison and the Mirage Missile effect can only reduce health to 1, although Sulfur Poisoning can send you into Deadly if it works long enough.
On the whole "Deadly" status isn't a pure example, both because it doesn't represent having 1 hit point - if your health is negative it's actually negative and is added and subtracted to normally - and because it doesn't represent a last chance. While the Will check to stay standing after additional injury when in Deadly status gets a bit more difficult over time, there's actually no amount of damage nor any number of hits even a beginning character doesn't have some chance of enduring. Eventually, surviving five or ten more blows of a force which dropped you from perfect health to Deadly will happen regularly. This is meant to represent a Milletian's ("Player Character species") Nigh-Invulnerability; Hit Points represent nothing more than your will to stay conscious, and even wounds or toxins can't actually kill you though they do affect your quality of life. It also adds to one of the game's charm points in that it's actually quite difficult to pin down somebody's - or even your own - "weight class" for combat just by looking at their statistics.
In Vindictus, (otherwise known as Mabinogi Heroes in Asia), a skill called "Life Flare" allows the player character to survive nearly any attack with one health point. The skill can be upgraded to allow a whopping 55% chance to occur.
In a similar example, new comer Hurk's ability "Impenetrable/Stonewall" reduces all incoming damage (when fully upgraded) by 65% and prevents any attack from dropping his health below one point. This skill is dependent entirely on the player's ability to dodge and counter attack, allowing a skilled player to survive an encounter on a single point of health no matter how many times they are hit.
The Rogue class in World of Warcraft has access to a deep Subtlety talent called Cheat Death. If an attack would kill the rogue, they have a set chance to survive it with a small portion of their total health remaining. An internal cooldown prevents this from happening too often.
Fire mages have a talent that, if an attack would kill them, heals them back to 40%... but sets them on fire for 12% of their max health per 1.5 seconds. This DOT can be avoided by using Ice Block (for 15 seconds, you take no damage and lose most debuffs, but otherwise can't move, attack, or cast).
In the Chimaeron battle, the raid gets a buff that enables attacks that would kill them to reduce them to 1 HP if they have more than 10,000 HP at the time, which is necessary to survive some of Chimaeron's attacks. For part of the battle, however, this is knocked offline, and the raid must stack up and get AOE heals to survive.
Paladin tanks have a stronger version of this, where they can activate an ability that causes them to take reduced damage and automatically heal for a significant amount of health when they suffer a blow that would kill them. The death prevention used to be active all the time on a cooldown.
Death knights are slated to get this option as a talent in the Mists of Pandaria expansion, on an automatic cooldown. They develop a shield that prevents damage but absorbs healing equal to the damage they would have suffered. If there's any absorption left in it when it expires they die, so they need to have a substantial heal coming in to survive.
Any otherwise-fatal attack in Copy Kitty brings Boki down to one hit-point (represented by a number flickering between 1 and 0).
In Mischief Makers, Marina can take one more hit after her HP is lowered to zero (with that last hit being represented by her gauge being all black & flashing red.
Rad Racer plays this trope, despite it being a cross country racing game. For most games of the same genre, it's a game over once the clock runs out. In Rad Racer, if the clock runs out, your car starts decelerating until it comes to a complete stop. This makes it possible to crawl over the checkpoint/finish line and keep playing. As long as your car is still moving when the clock runs out, you still have a chance.
Excessive Rate mode in Sound Voltex (which fails the player when they hit zero life, instead of the standard "finish song above lifebar quota" setting) normally subtracts about 10% of the life gauge per miss, but will drop the player to "0%" before failing them outright, after which one more misstep without raising the bar even slightly results in a TRACK CRASH.
Ancient Domains of Mystery has your character survive a powerful attack with one last lousy hit point suspiciously often, provided their Luck Stat (and presumably your own) is high.
In the vaguely similar Caverns of Larn, upon receiving a blow that would normally kill you, you will occasionally be informed "you feel wiiiiiiierd all over" (sic) and survive, with one HP left.
A 1.5% chance of this can be purchased in Rogue Legacy up to 10 times, for a cumulative 15% maximum chance of avoiding death with one hit point left. The ability can also be triggered multiple consecutive times.
The Gutsy IQ/Team skill in the Pokémon Mystery Dungeon series gives you a high chance of surviving a fatal blow, even if your HP is already at one. Enemy Pokemon with the ability are understandably extremely annoying to deal with at times.
Breath of Fire II allowed Ryu to do this. If he takes a hit that would have otherwise killed him, there's a small chance you'll see a message that says "Ryu (or whatever you named him) grits his teeth, gets back up" with 1 HP left. Higher Guts rating increases the chances of this happening. Breath of Fire 3 also allowed this, and every group member had their own unique quote that they would say when it happened.
In the Exile and Avernum RPG series, characters who hit zero HP were still able to fight, but one more hit would kill them and scatter their inventory about the battlefield.
Furthermore, having a high Luck stat gives you a good chance to survive that One Last Hit several times in a row.
The "Persistence" passive ability in Lost Odyssey has this effect once per life (i.e. the character must die and be revived to reactivate it.)
In the Monster Rancher series, monsters can sometimes endure a KO hit with the Grit ability. In certain games, all monsters have the ability to endure with Grit, but in others (such as 2 and DS,) only those with the specific talent for it can pull it off.
Notably, this can happen repeatedly over the course of a single fight, with an enemy who is consistently flattened by every attack, only to stay up with that one final hit point.
In Pokémon, the "Endure" move guarantees the user will survive the next attack (even a One-Hit Kill) with at least 1 HP, but may fail to take effect if used consecutively. The "Focus Sash" item (and, as of Black and White, the "Sturdy" ability) can guarantee this if the user's HP is full when they take a hit, and the "Focus Band" item provides a 10% chance of this effect at all times.
The Focus Sash can also be abused with a metagame strategy called "FEAR" (Focus sash, Endeavor, Quick Attack, Rattata), where a very low-leveled Rattata wearing the item would get hit, survive with 1 HP, use Endeavor (which cuts their opponent's HP to match their own), then Quick Attack (which always hits first) to deal the Scratch Damage needed to KO the opposing pokemon. The fact that a Level 1 Rattata could faint even a Level 100 opponent makes it Cherry Tapping incarnate. However, it's fairly easy to avoid if you know what's coming. As of Generation 5, the ability Sturdy works like the Focus Sash, and unlike the Focus Sash, it will work an infinite number of times if the pokemon can be restored to full health beforehand. This allows a level 1 Aron in sandstorm to sweep an entire team by using Endeavor to cut the opponent's health to 1, holding a Shell Bell (which restores HP equal to a portion of the damage taken, almost always enough to refill Aron's health), and then letting the sandstorm finish the job.
It can be hard to pull off, but skill swapping Sturdy onto Shedinja gives it an always-active Last Chance Hit Point and can only be killed via passive damage. This is because Shedinja is at one HP and full health, triggering Sturdy each time it's hit.
False Swipe is an attack that will always leave the opponent with at least 1HP remaining. Because the main point of Pokémon is to capture them by first weakening them so they can't escape from the Pokéball, an attack that leaves them with the lowest possible health is very desirable.
In Generation 6, any Pokémon with maxed-out affection has a chance of withstanding a lethal blow with one HP remaining a la Endure, no matter how damaging the hit nor how much HP they had remaining, just because they love you that damn much.
Rogue Galaxy, provided that the character's HP wasn't already critical before taking the hit.
Clock Tower 3's Panic Mode. While Alyssa is generally invincible, if the Panic Meter fills up, she freaks out, and the player must guide her away from that area's Big Bad until the meter lowers enough, if Alyssa is hit by any attack while in Panic Mode, she dies.
The "Guts" ability and "Angel Curio" items in Valkyrie Profile enable this, giving the character a chance of surviving any attack with a few hitpoints. Notably, it doesn't have a lower threshold for working, so it's possible for a character with 3 HP to survive attacks dealing hundreds of thousands of HP worth of damage round after round, and when they finally DO end up dying, another character with Auto-Item can revive them right afterwards without using up their turn, the only penalty being that they're not able to act on their next turn. The game expects you to abuse this. The final bosses have multiple attacks that either deal several times more damage than your HP cap or kill you outright without a miss chance.
EarthBound'sGuts stat, along with affecting Critical Hit rate, gives a character a small percentage chance to endure an attack that would have dealt mortal damage, leaving them at 1 HP instead. This is indicated when the message that would otherwise read "mortal damage" omits the "mortal" part of the message — even if the damage dealt matches or exceeds the character's HP, characters only head toward 0 HP when mortal damage has been suffered. Secondly, even if a mortal blow is incurred, the rolling HP meter mechanic allows the player to avoid a KO if they can finish the battle or heal before the character's HP actually rolls down to zero.
Elwyen in MARDEK: Chapter 3]] has a defensive reaction ability along these lines, which allows her to survive an unlimited number of attacks with 1 HP remaining so long as she had more than 1 HP before the attack. It's a bit overpowered, and one of several factors that contribute to Elwyen being anything but spoony.
Super Mario RPG has certain enemy attacks that cause instant death to a party member. All of these attacks are classified as physical, and almost all physical attacks can be blocked by pressing a button just before the attack hits. If one of these attacks is blocked, that character will not die, but will be left standing with only 1 HP (though if the block timing is truly impeccable, that character may take no damage at all).
Shin Megami Tensei has the Endure passive skill, in which the user, upon death, gets revived with 1 HP remaining. However, this can only activate once per battle. Enduring Soul takes it further, giving the user a full heal upon death, again no more than once per battle.
Shoot em Up
In Akai Katana, if you're on your last life and have bombs in stock, taking an otherwise lethal hit will automatically trigger a bomb, which in turn gives you a moment of invincibility and allows you to escape unscathed. However, this comes at the cost of all your bombs, even though it only has the effectiveness of one bomb.
Any attack that would kill you in Alien Soldier will leave you with 1 HP, if you had more than that. Since you can create healing items (by hitting enemy attacks with a certain attack of your own), this can help keep you alive for a while. And yet, the game still manages to be Nintendo Hard.
In the Gundam Vs Series, the older games had the Revival ability, which would sacrifice a Mobile Suit's limb (and a degree of performance) in exchange for about 100 hit points. If you stay alive long enough to refill the meter, you can get another Last Chance Hit Point, losing another limb. In the crossover games, a few MS have the ability in imitation of Signature Scenes from the anime; for example, the Zeong's head can continue fighting without the body, while Gundam Exia becomes the Repair version from Gundam00's second season.
Kid Icarus: Uprising: If your health drops to zero your health bar shatters, leaving you in "Crisis Mode". At this point any more damage is fatal. Survive for long enough and your health bar comes back with a very small amount of health on it.
It is possible to survive a single very weak attack in Crisis Mode, but it's more luck than anything. Conversely, if you get hit by a very powerful enemy at low health, you may get killed instantly without going into Crisis Mode.
Star Fox 64's health bar will drop to empty and give you one more chance, even if the hit should have been enough to kill you. At that point, any hit will destroy your ship unless you get more health first. Also, the heat in Solar can empty your bar but won't destroy the ship.
In Phantasmagoria of Flower Viewing, the characters have hit points, but the last hit point (or rather, half a point) is special - anytime a character would've lost all her HP while having more than half a point, she would instead keep that last half a point until she gets hit again, and her spell gauge will max out (rather than increasing by one level as per when she's hit otherwise).
U.N.Squadron (the videogame translation of "Area 88") has two variations, where fuel supply equals the life of your plane:
In the arcade version, when you're down to your plane's last bit of fuel, the sirens go off, and your pilot's picture flashes red. One more hit before you kill that stage's boss, get a partal fuel tank refill (looks like two capsules put together) or a yashichi (looks like a pinwheel, and gives you a FULL refill) and it's game over.
The SNES version has it where one hit causes your plane's fuel bar to read "Danger" as well as the other two signs. If you can avoid another hit for a certain time period you get your fuel bar back less damage, but if you get hit again you lose your plane (and a life). Once you get your bar back, though, another hit puts you back in "Danger" until either you avoid getting hit, you get hit before then, or you finish the stage without taking further damage. If you're down to your last bit of fuel you'll be stuck in "Danger" until you either lose your plane, you get something that refuels your plane, or you finish the stage.
The Guardian Legend has your character's shields. If you took an otherwise lethal hit with shields remaining, they would drop to zero. You would be killed if you got hit by anything at zero shields.
In Wartech: Senko no Ronde, each player is given a last chance hit point when their lifebar is zero, indicated by a full flashing bar and the pilot exclaiming something. This not only gives them more maneuverability, but also makes their hitbox smaller and maximizes their energy bar (This is called "Vanish" mode). If they have at least one B.O.S.S.Stock left, the B.O.S.S. Mode will be inordinately stronger, gains new and more powerful attacks, and the energy bar depletes slower. This allows for very cinematic (and sometimes frustrating) comeback battles. Savvy players use their B.O.S.S. Mode when their opponents reach this last chance hit point, to utterly seal their fate. Of course, if the opponent is skilled enough, they might survive anyway.
In Super Aleste, getting hit reduces your shot power by four levels (out of six), or level 0 at level 1-3. Getting hit at level 0 kills you. However, you can never die at level 1 or higher unless it was due to geting crushed by a wall, so as long as you keep yourself out of level 0 you can keep going.
The Fallout: New Vegas Dead Money DLC, if played on hardcore mode, enforced this. It started you without any health items and forced you to run around a gas cloud which gradually drained your health... but stopped at 1HP. You still had to fight enemies (who were in hazmat suits and thus not affected by the cloud), effectively making you a One-Hit-Point Wonder unless you were incredibly lucky filling up on health items during the entire first half of the DLC.
In Rune Factory 3, you can also build this up as a stat. Getting KO'ed builds your resistance to Death (which is distinct from the Knockout stat, where you're just dizzy and immobile). This will cost you much cash (as going to the hospital cost you a chunk of your money every time), but this will give him a chance to weather an otherwise lethal attack with time to whip out a healing spell or item.
Several Shin Megami Tensei related games have such a skill for your characters, which is quite useful if you get a game over when your hero dies. In Persona 3 and Persona 4, there is even a stronger version of that skill (or item) that replenishes your HP when you die once per battle.
Clock Tower 3's Panic Mode. While Alyssa is generally invincible, if the Panic Meter fills up, she freaks out, and the player must guide her away from that area's Big Bad until the meter lowers enough, if Alyssa is hit by any attack while in Panic Mode, she dies.
In Parasite Eve 2, you can pick up a piece of armor called the Chicken Plate; if you wear it, then receive a blow that would normally kill you, it will keep you alive for exactly 1 HP. This item is only available if Flint the dog dies after an important boss fight.
In Resident Evil 4, if Leon is at low health and is hit by a non-lethal attack, he will fall down, then stand back up, giving the player one last chance to heal or escape.
3rd Edition Dungeons & Dragons rogues can get "Defensive Roll" which allows them to sometimes take half damage from attacks that would otherwise kill them.
The Harm spell allows a save for half damage. If it would still bring them to 0 HP or less, it instead stops at 1.
In Rifts, if your MDC armor is totaled, it absorbs all the damage from the attack that destroyed it - no spillover. This is an example because one point of MDC damage to an unarmored human invokes the Chunky Salsa Rule.
The "Hard to Kill" ability in Malifaux is a straightforward example: So long as a hard to kill model was not on its last wound already, any attack will only drop the model to one wound.
The Super Guts evility in in Disgaea 3 and Disgaea 4 allows its user to survive a fatal attack with one HP if they had full HP when it connected. The Deathsabers in 4 have a variation on it that works as long as their HP is above one, but puts them to sleep after the hit lands.
In Fire Emblem: Path of Radiance, Mist starts with a skill called "Miracle" that halves any lethal damage, making it possible to survive with or close to 1HP. Of course, if even half damage isn't enough...
In Radiant Dawn, with the new Skill system, anyone can use Miracle now, and the skill was changed so that a lethal attack instead halves the unit's HP (or deals 0, if the unit is down to 1 HP already.)
In Front Mission 3, a skill called "PrvntLoss" is Exactly What It Says on the Tin: If any one part is about to be blown up, the skill activates, and the damage is limited so that the part will have exactly one HP left. This often means the difference between victory and defeat.
Lufia: Curse of the Sinistrals has this for three of the six characters - Maxim, Selan, and Dekar can, after specific story events, obtain titles that give them this property.
Mega Man Battle Network has an equippable program ("Undershrt") providing this effect. This can lead to a Game Breaker in the right circumstances. If you use a Wood style (which regains health while standing on grass), and turn the stage to grass, and your opponent has no way to change the stage tiles and no fire attacks (which burn grass) - then you become impossible to kill with Undershirt. Whenever your opponent hits you with a mortal blow, you'll hit 1 HP for a split second, then immediately start gaining health before they can hit you again. (That said, many opponents do have ways of changing the stage tiles, so you'll have to use one of the other many game breakers in the Battle Network series against them.)
Was fixed starting from the fourth game, where the rate of HP regen became dependent on how much HP you have left, slowing to a crawl while you have one HP left so that you're vulnerable for a period of time.
In 3, Bass will actually get around it during your Hopeless Boss Fight against him, despite not being fixed by that point, however he is the only enemy to ever do so before they fixed it.
Likewise, Mega Man in Mega Man Star Force can also equip this ability and the aforementioned combo still works, though it's more troublesome to get grass panels on your side of the field.
A variant used in XCOM: Enemy Unknown allowed a lucky (?) soldier to be "critically wounded", requiring the attention of a Medkit or to complete the mission before they bled to death, rather than the usual instant death. A stabilized soldier had 1HP and was still vulnerable to AoE damage and would be out of commission for a fair length of time (plus a permanent Will stat reduction) if they survived, but many a Commander would take this over losing them permanently.
The Enemy Within DLC added a Gene Mod perk that would guarantee this would happen, with more time to stabilize and no Will penalty. In both cases the soldier was still effectively "dead" as far as combat effectiveness for the mission went, barring the use of Revive, but they were at least still breathing.