Ret-Gone/Tabletop Games

Examples of in  include:

Card Games

 * In Magic: The Gathering, the card Door to Nothingness does this, according to its flavor text (see page quote above).
 * So does the card Aether Snap: "May you wake to find you were only ever a dream"
 * You can actually do this to yourself with the Pact cycle, flavor-wise. These involve borrowing mana from the future. When it's time to send mana into the past, if you can't, you erase yourself from existence.
 * Apparently it happened to Zhalfir. Teferi "phased it out" (transported it to the future) to prepare for the Phyrexian invasion, and when it was time for it to "phase in", it couldn't.
 * In Chrononauts, this is done with the aptly-named card "Your Parents Never Met". The chosen player's Secret Identity is revealed, and they must trade it in for a new one.

Tabletop RPG

 * In Feng Shui, individuals on the losing side of the "Secret War" often suffer this fate. They don't cease to exist, but rather find that the world as they know it has suddenly changed all around them, no one other than themselves (and other time travelers) remembers their version of reality, and they themselves have no past in this new version of reality - no family, no home, no friends, no identity - because they never existed in it to begin with.
 * In Exalted, this is one of the things the penultimate technique of the Charcoal March of Spiders style can do.
 * In addition, one of the Yozis, She Who Lives In Her Name, did this to huge portions of Creation before being sealed away. It's still debated amongst the fandom whether she "merely" destroyed things and erased them from living memory, or whether she rewrote the laws of Creation so that the things she scythed away could never come into existence again.
 * In Mage: The Awakening, the Red Word cult (who worship an alternate timeline so abhorrent that it was aborted from reality into the Abyss, where it attained sentience and got really pissed off), devour people in order to symbolically wipe them from this history. If the do it in their sacred temple, it actually happens with all evidence that the person existed gradually fading away.
 * In the same game, the Cult of the Doomsday Clock are attempting to destroy the Fallen World (i.e., this one) in order to free themselves to Ascend to a Higher Plane of Existence. (Needless to say, the heads of the cult are all Abyssal beings.) Their key weapon for this is a Doomsday Clock, which not only erases everything around it, but goes back through time and erases it there, eventually leaving a gaping hole in both the world and history.
 * Though not officially part of the original Mage: The Ascension, online fan-created material suggests that the Syndicate and New World Order factions could do this by way of Unperson, due to their paradigms of magic.
 * Mage: The Ascension - the Arcane background is a sort of "cloaking" from the Universe. Records, memories and evidence for the existence of an Arcane character slip away from the world, slowly at low levels ("You're easy to forget.") while at hight levels people start forgetting you as soon as you leave the room (the five dot version's description is "In other people's minds, you don't even exist."). Oh, and the stat potentially goes up to ten for NPCs (and really powerful or unlucky PCs). Not bad for mages, who really want to hide from the world, but it may become a hindrance other people. Think The Net. The Virtual Adepts can do that. Don't piss them off.
 * In a book on magic for Vampire: The Masquerade, there is a spell that erases the memeories of a person or object from existence completely. However, a character's connections can help them resist, on the principle that it gets harder to make everyone and everything "forget". Also, trying to remove important or big things won't work completely, as the universe will try to fit something else in the hole. For example, if a building in the middle of town is erased from existence, you won't end up with an empty lot; something has to go there, so some other building will appear.
 * The Excrucians in Nobilis aim to do this to all of creation, one aspect at a time. Nobles can, themselves, to a more limited extent make retroactive changes to physical existence and history. A minor element of the game Backstory speaks of the five hundred years of human progress which got unmade, changing history considerably.
 * In GURPS the disadvantage Unique makes one vulnerable to this and the advantage Temporal Inertia makes one invulnerable to it.
 * Also, there is no GURPS 2nd Edition. Even the Warehouse 23 doesn't mention it.
 * 3rd Edition GURPS was a massive rewrite from 2nd Ed, but 2nd Ed is shown on their book list. fnord.
 * The D20 setting Infernum incorporates Ret-Gone into its background; get swallowed by a Hellgout (a kind of naturally occuring portal that links Hell and Earth, which usually ends up acting like a black hole) and Earth will basically rewrite itself to wipe out your existence, with any remaining hints that you ever existed being subtle ones, a process referred to in-universe as "The Twisting". For example, the Knights of the Harrowing are the descendents of an order of overzealous Christian Crusaders called the Knights of the Sepulchre, an order dedicated to the reclaimation of the tomb where Jesus Christ resided for three days after being crucified, who deliberately invoked a Hellgout to swallow their fortress so they could lead a crusade against Hell. The vast majority of the deeds they accomplished have either been erased from history, or attributed to other orders. A rare few examples of their symbol, a charging crusader on horseback, are occasionally found on crumbling ruins in either the Holy Land or south France.
 * Inverted in the Mystara D&D setting's Alphatia, which was destroyed in the Wrath of the Immortals campaign-arc and recreated in the Hollow World by the Immortals. To recreate the population, they first resurrected the Empress, then everyone the Empress remembered, then everyone they remembered, and so on. Many isolated villages and antisocial individuals were omitted from the restored Alphatia, as none of the Alphatians who did get restored had missed their presence. For them, being forgotten became the cause of non-existence, rather than the effect.
 * Speaking of Dungeons and Dragons, the Dragonlance setting has rules for fighting the minions of Chaos (also mentioned under Literature.) Die to them, and all you'll leave behind is empty armor and any books that were written about you (the latter of which will be assumed to be fiction.)
 * In core Dungeons & Dragons, the LeShay are an ancient (as in, Time Abyss), very powerful (as in, epic-level) race of fey lords who claim this happened to their entire society. Supposedly, they had a vast inter-planar empire that existed before the current multiverse, but some sort of cataclysm not only wiped it out, but erased its history from the memories of all other sentient beings. They do not say exactly how his happened or who was responsible, but they do say that trying to restore it would result in an even worse cataclysm that would erase countless billions of lives. They aren't eager to make the attempt.
 * The very highest level spells of the Destruction Path in the Anima: Beyond Fantasy RPG allows a mage to erase anything from existence. From a single person to an entire species or continent the Uncreation spell completely stops it from ever having existed at all, with the timeline changing to match. Only people with a very high Gnosis (basically how important they are in reality) can even notice that something is different.