Justified Extra Lives

In some games, Death Is a Slap on The Wrist. Occasionally, the game will go out of its way to explain exactly why this is the case. The most common Handwaves are "your characters are clones" and "the game is simply a re-telling of events that already happened." The latter will sometimes combine it with a Take That to the player on the Game Over screen with your character saying things like, "Of course, it would have been incredibly stupid of me to do that."

It should be noted that this isn't necessarily a good thing; players are so used to having extra lives or continues that the attempted explanation may only serve to emphasize an artificial scenario they'd otherwise have been perfectly happy ignoring. This is particularly true when the explanation is prone to Fridge Logic.

A form of Gameplay and Story Integration.

Action Adventure Games

 * In Shadow Man, killing Mike LeRoi sends him to Deadside just like everyone else. Unlike everyone else, once there, he becomes Shadow Man, whose powers include the ability to cross back over to certain locations in the world of the living.
 * Chakan The Forever Man's immortality works similarly. He can be killed, but it just brings him to his inter-dimensional hub where he can go right back to where he was.
 * Similarly, the Soul Reaver games/portions of the Blood Omen games, Raziel dying in the physical world causes his corporeal body to dissolve and he returns to the spirit world, until he can find a gateway to create a new physical body. If he dies in the spirit world, he dies completely.
 * No, his soul is snatched back by the Elder God. In the others, his soul seems to have become strong enough to reform itself. This is mostly because
 * Kain himself transforms in a flock of bats and reforms in a safer location.
 * Maximo has an offer from Death, where Death will return him to life as long as he continues to work towards resolving the imbalance in the afterlife. This deal is bound by a physical coin Death gives him, and if he runs out of these coins, Death can no longer restore him to life and must reap his soul properly.
 * Amaterasu in Okami is the sun goddess, so she can return to life at the cost of a single unit of solar energy. If all the units run out, she can revive herself yet again if she has filled a special Celestial Pouch. Add a special item which can refill said Pouch instantly and you have a functionally immortal character.
 * Aliens Infestation for the DS has you controlling a four Marine fireteam, one soldier at a time. If one Marine is killed, another will take their place. There are a couple of wrinkles: if your fireteam is short a member or two, you can find other Marines to join your fireteam throughout each level (They'll refuse if you already have a full fireteam.) Also, if a Marine gets incapacitated by an alien, they're dragged off to a nearby lair instead of killed, and can be rescued.

Action Games

 * In V2000, the manual makes the player one of a number of pilots who fly drone craft remotely. Stocks and manufacturing capacity are both limited, so priority is given to those pilots who prove the most effective against The Virus and penetrate the furthest into its domain. A magnificent example. One that falls apart as soon as hidden trophies start giving lives, but magnificent.
 * The way Alien Shooter describes extra lives is this: the scientists have finally found the method to dodge death, so they give you several in the beginning and several additional lives during your mission, after you pay them loads of money.
 * Tenchu uses the Ninja Log for extra lives--you didn't die, you replaced yourself with a log. It only works if you die by via combat or trap damage though, falling into a pit means you need to start the level over.
 * Teenage Mutant Ninja Turtles for the NES gives the player control of each of the four turtles one at a time. If they run out of life, April O'Neil/Splinter will inform you that they "got caught." This turns out not to be a euphenism - if you're down a turtle, you can find them tied up in a chair and rescue them in certain spots.

Adventure Games

 * Tex Murphy: Overseer presented the entire story as a flashback, with all player deaths handwaved by Tex: "Of course, I'd have to be an idiot to do that. Here's what really happened."
 * In The Secret of Monkey Island, protagonist Guybrush Threepwood can die (if you're really, REALLY trying to). However, in Monkey Island 2: LeChuck's Revenge, the premise is that Guybrush is telling a story to Elaine, so any death would be inconsistent with the fact that he's alive enough to tell about it. Still, in one scene, Guybrush is hooked up to a timed death contraption. If you fail to deactivate the machine within the allotted time, he drops into a vat of acid, at which point Elaine reminds him that he's telling a story. The game then returns you to the beginning of the contraption scene.
 * The premise of Shadow of Destiny is your character using time travel to prevent his death; if you fail to do so you can just go back in time and try again. Note that it is possible to die permanently,  You can still reload your saved game, though.

First-Person Shooter

 * Alien vs. Predator on the Atari Jaguar had the Alien able to lay eggs in Marines. If you died, you would continue from the new alien that was hatched.
 * In System Shock, this has to be turned on for each area by finding its BS-tech resurrection chamber. Initial incursions may be short and cautious until the chamber's discovery creates a bridgehead.
 * Spiritual Successor Bioshock has the Vita-Chambers, which work similarly.
 * Left 4 Dead sort of uses this. Every time a survivor dies, he will respawn in a closet down the road and thank you for releasing him. The developers used this as a way to simulate how the survivors would find other survivors that were alive. In other words, if a survivor dies, it never really happened as long as you find him in a trapped closet and release him. Only when he dies in the finale will the game consider him Killed Off for Real.
 * In The Darkness video games the Darkness itself will not allow Jackie to die . This is a plot point several times in the first game.
 * Portal2: While this is averted in the single-player campaign, the co-op gives a justification. The players are robots; upon "dying" their data and personalities are transferred to a new body and plunked back in with their buddy. The choice of using robots was actually to avoid Fridge Logic, and the horror of seeing a human character die in hundreds of really painfully creative ways.

Interactive Fiction

 * Spider and Web: In this interactive fiction game, the framing story is that you are a captured spy being interrogated. If you died in your retelling, the interrogator would be cross with you and make you start over.

MMORPGs

 * Eve Online explains this with clones. And actually goes for more realistic approach - when your ship has been blown up, you survive in an emergency escape pod. If you manage to get away in that, you only lose the ship and cargo. If the pod has been blown up as well - then the clone justification comes into play. You lose all the implants your original body had and all the skills that you have learned after you have updated your clone.
 * In City of Heroes, the explanation is that every 'registered' hero has a teleport homer on them, that teleports them directly into an ultra high tech tube that revives them if they should be too badly hurt or rendered unconscious. In the original comics run from the earliest days of the game, the climax is made more dramatic by the bad guys having jammed said teleport homers. In addition, at least one mission deals with stopping bad guys BEFORE they can disable the hospital teleport system.
 * The MMORPG Shadowbane explained the ability of characters to come back from the dead as something terribly wrong, but consistent throughout the world. Nobody could permanently die. At all.
 * Fusion Fall: The Grim Reaper is on your side, so he just revives all casualties at the last checkpoint.

Platformers

 * Prince of Persia: The Sands of Time is presented as a story the titular character is telling. If you die, he'll say something along the lines of, "Wait, no, that's not how it happened, may I start again?", allowing you to try again.
 * which leads to some interesting Fridge Logic when you think about it. "So I scaled the wall, jumped off just as the platform retreated, and fell thirty feet onto spikes, killing myself in a gruesome manner. Wait, hold on, that doesn't sound right, let me start again..."
 * It's possible that since the story would already include many seemingly fatal accidents reversed by the Dagger of Time, the Prince was retracting a telling of the story that would break its limitations - the only circumstance in which the player is likely to get a game over - because he knows is clever enough to spot them too and call him on it.
 * It's also possible the prince is confused by the images of the future he sees at the save points. He see's so many images of himself dying in the future it would make sense he gets those confused with his actual experiences and "remembers" dying.
 * Psychonauts describes extra lives as "layers of projection": Lose enough and you get booted out of whoever's mind you happen to be inside. It's unclear as to why this also happens in real life, though...
 * Conker, titular hero of Conkers Bad Fur Day, has as many lives as he has tails. The grim reaper of his world, a tiny foul-mouthed skeleton named Gregg, explains the deal to you the first time you die.
 * In Prinny Can I Really Be the Hero, you get 1000 lives to solve the puzzles. That's not one Prinny with 1000 lives, but 1000 Prinnies dying one after another.
 * The Futurama video game does this, thanks to Professor Farnsworth's invention, the Re-Animator (no, not that Re-Animator), which revives the player after every death.
 * Super Meat Boy seems to not justify this...
 * Donkey Kong Country Returns uses balloons as extra lives like the original trilogy, except this time the game shows your Kong being carried back into the stage by the balloon if he dies.

Real Time Strategy

 * The game Sacrifice: The game missions are narrated by the hero. Failing and restarting them makes the hero turn out to be an Unreliable Narrator and say, Of course, that's not what really happened. Let me start again...
 * In addition, dying isn't much of an issue because your patron deity's got your back (or your soul, at any rate) and will restore you to life once your mana has recovered to 25%. As long as your Altar is intact, a wizard can't die, and thus the main way to win in Sacrifice is to desecrate your opponent's altar to keep the wizard from reforming.

Role Playing Games

 * In Neverwinter Nights, a character who dies is pulled back to the nearest temple of Tyr and gets a lecture from the head cleric about how they almost lost him/her that time.
 * In the Shadows of Undrentide expansion, you get a magic ring that does the same thing (but pulls you to Drogan's house instead of a temple) in the first chapter, except it has limited charges (depending on how many Focus Crystals you have)
 * In the Hordes of the Underdark expansion, you get a magic relic that pulls you to a pocket dimension, and has limited charges (depending on how many Rogue Stones you buy) for the first two chapters.
 * Done rather literally in Planescape: Torment, as the player character is immortal.
 * Every time your mech is destroyed in Artix Entertainment's free Flash game Mechquest, you're told that you managed to eject.
 * AE used this earlier in Adventure Quest. While losing a battle actually causes you to die and meet The Grim Reaper, he has always filled his soul quota for the day by the time you reach him.
 * my be fridge brilliance, considering what you were doing up until the point that you died.
 * Phantasy Star II, unlike most western RPG titles, literally does have your characters dying for real if they're slain in battle. You then have to go to a Cloning Lab to have the dead character cloned into a new being possessing the old one's abilities and memories.

Shoot Em Ups

 * Stargunner tries to explain its extra lives by claiming that they're actually some sort of warp devices that activate automatically when you die and proceed to "teleport you to the closest compatible parallel dimension".
 * Ray series like Ray Storm and Ray Crisis have varying degrees of justification. On Ray Storm, you can clearly hear the radio voice upon your death(s) saying "Ray 2/3 to continue present tactics." Yes, it's not so much that you have extra lives, it's that We Have Reserves. Ray Crisis, on the other hand, takes place inside an immersive AI construct of a cyborg called Con-Human, and your fighter really is a virus designed to wreak havoc. Presumably then, your lives are the number of times the virus can regenerate after the Antibodies have killed it.
 * Thunder Force V's story introduced it as a cloning system called "Circulate Death"
 * The Amiga game Walker justifies this by each of your three lives being a different mech. They are even referred to as Walker One, Two and Three.
 * Hellsinker's manual says that extra lives are due to the [LIFE] system, which excised the concept of being alive, and split it into seven parts. Of course, this being Hellsinker, it's not clear how seriously this is meant to be taken.

Simulation Games

 * Sim Ant allowed you to be reborn as another ant if the ant you controlled died.

Stealth Based Games

 * Metal Gear Solid 3 Snake Eater is presented as an apparent simulation of historical events, so if you die (or take certain actions), it creates a "Time Paradox", as that's not what "really" happened, and you have to try again.
 * In Assassin's Creed, the player character is plugged into a machine that accesses your ancestor's memories. When you die, it's called "memory desynchronization", and you have to access the memory again and do it the way your ancestor did it; i.e., the right way.
 * Gets interesting when you realise what else causes desynchronisation. Apparently said Ancestor did a perfect, never injured, never even seen, 100% run through. Badass.
 * Considering most injuries would either severely cripple or kill him, he'd pretty much have to do it in a perfect go.

Third-Person Shooter

 * In Brute Force, a dead player is replaced with a clone created for the purpose. This is expensive.
 * Lampshaded in a few places, such as when your commander tells someone to prepare a backup clone just after ordering you to jump through an untested teleporter without knowing where it will go.
 * 'Lives' in Total Overdose are called 'rewinds', and results in the action winding back from death to allow more survivable choices -- sort of like an instant internal Retcon. If the player is painted irreversibly into a corner anyway, that just displays how many ways the character can die, until you're out of rewinds.

Web Games

 * The flash game Dino Run calls lives "time shifts".
 * And the game pause "time freeze". (Is there a trope for this?)
 * The recent platformer Liferaft: Zero's protagonist is a female text subject with TONS of her clo- sisters backing her up, all eager to go out and get that candy.

Wide Open Sandbox

 * The Destroy All Humans! series replaces each dead player character with a sequentially numbered clone.
 * Crackdown features clone replacements. In fact the "Extract" option just instantly kills your character and pulls up the menu to choose where you want to respawn. It's only the loss of your current progress towards the next upgrade level that prevents it being a better method of transport than driving to get across town.
 * Spore: The Cell and Creature phases show that every time you die, you emerge as another member of your species, ready to continue. The Space phase explains extra lives as a combination of "advanced cloning technology" and "emergency consciousness transferal", having you re-emerge as a freshly-cloned pilot with a rebuilt ship after dying.
 * If you happen to explode on you own planet, the pieces of your old ship will still be falling from the sky as your new ship flies up through them.

Anime and Manga

 * Fullmetal Alchemist: The unfinished Philosophers' Stone will not restore human life, but serves to act as extra lives for the homunculi. Thus, one can kill a homunculus either by destroying the stone, or by killing them over and over again until they run out of lives.
 * How does this work?
 * The source of Alucard's indestructibility in Hellsing is that as blood is the currency of life, he has as many extra lives as there are people he has drained unto death. How many is that? Approximately 3.4 million.

Film

 * The 6th Day: The villain has access to Cloning Gambit at $1.2 billion a pop, and plenty of billions to burn, so the Goldfish Poop Gang keeps coming back. This does not apply to the hero.
 * What Dreams May Come:
 * Little Nicky from the film of the same name dies early on, but that just sends him back to hell, and he's sent back up for another try.

Tabletop Games

 * In Paranoia, each character is actually six identical clones (officially referred to as a "six-pack" and usually tracked with one), to get around the fact that any imaginable action or thought is treasonous (and treason is a capital crime).
 * Dungeons and Dragons and Order of the Stick have resurrection spells. These aren't perfect, though - you need expensive material components to pay for them (the old joke is "Life is worth 5,000 gold pieces"), some deaths can't be resurrected from, and the soul has to want to come back. In the latter,
 * Alternity: AIs have backups stashed somewhere on The Grid.
 * Car Wars featured 'life insurance' in the form of Gold Cross. For a modest fee, they'll grow a new clone from your corpse, or keep one as a backup.
 * Transhuman Space allows "digital characters", such as ghosts and artificial intelligences, to store backups of their code on other servers so that they can be restored to life.
 * Eclipse Phase allows anyone to make digital backups of their consciousness that can be "resleeved" in a new body (though you need to pay for it or you could end up in whatever cheap morph Firewall found for you). There are also cortical stack implants that can save a character's memories up until death.

Web Comics
"Ran: But Mommy, isn't rebuilding me expensive? Kalinka: No, Ran, you're made with really, really cheap Soviet parts. Ran: But if you replace me every time- Kalinka: Really, really cheap Soviet parts. Ran: But wouldn't it be- Kalinka: Really, really cheap Soviet parts!"
 * Bob and George features the communist robot Ran, who is built so crappily that even a slight poke can kill him. Cue his creator building a Ran factory which teleports a new Ran exactly where the old one died.
 * This being Bob and George, this is used, abused and lampshaded to death and back.

Western Animation

 * South Park does this with Kenny, who was killed off every episode for about six seasons before getting around to explaining how he kept coming back.
 * In Garfield His 9 Lives, God decides to give more lives to Garfield and Odie because he thought their last life (blown up by an alien fleet) put them in an "unfair position".
 * Fry, when asking the What-If Machine "What if that stuff I said?" on life being like a video game, is killed but walks in from off screen declaring "I had an extra man". An interesting use of the trope in that he was justified in coming back to life in reality BECAUSE life was like a video game.