Many third person games do this — Grand Theft Auto, Zelda, etc. Any game in which the character has an extensive inventory.
Chibi-Robo pokes a little fun with this, actually having characters occasionally comment on his ability to store objects larger than himself (he's only a few inches tall and about the shape of a bolt) in his body and then retrieve them later as needed. Somewhat ironic, though, is that although he's not limited in the number of different items he can carry, there is a limit to the quantity of each item.
Also, items don't just appear in his hand when he needs them, he has to literally pull them out of his head, which can take some time if it's a large item. One sidequest has Chibi-Robo stuff an entire three-masted pirate ship into his head. It takes a few seconds to pull it out again.
Almost Every Zelda game arsenal includes a "heavy"-type weapon...usually a hammer. Except for in Twilight Princess, when he carries a ridiculously enormous ball and chain which slows him down considerably while he's carrying it in his arms, but somehow has no effect once he's put it back into hammerspace. He also gets a pair of heavy Iron Boots, which allow him to walk on the bottom of the water.
From The Legend of Zelda: Ocarina of Time onward, his typical animation for pulling something from the inventory is reaching behind him. If he's wearing a shield, it looks like he's reaching underneath it, but once his shield is gone, he simply reaches behind him and the object appears in his hand.
In Twilight Princess, there is a tiny pouch specifically modeled on Link's belt, behind his hip, which he reaches into to retrieve and stow items, including the aforementioned massive ball and chain item.
The fanfic Free as the Wind handwaves this by repeatedly referring to the Links' magic pouches, which they keep under their shields. It's the most logical explanation a human being can come up with, sadly.
He can produce bombs bigger than his head by simply raising his hands in the air; in the Nintendo 64 games, he either never even bothered to reach back and grab one, or it was done so fast you didn't even notice. He can hold, unencumbered, up to 50 of those things... somewhere.
Apparently he keeps them in very limited extra-dimensional "bomb bags," which only bombs can fit into and which activate and teleport their contents into his hands whenever he raises them above his head. You don't want to be standing next to this guy in a crowd doing "the wave!"
Unless it is tied to the Spirit of the Hero which as of Hyrule Historia is practically confirmed to be a part of all incarnations of Link. It could as such be a boon granted by Hylia when she blessed the spirit of the first Link.
Several fighters in the Super Smash Bros. series use this. Peach in particular has a parasol, a tennis racket, a frying pan, a golf club, teacups, and TOAD, that all come out of nowhere.
Peach somehow manages to turn the entire stage into her own personal hammerspace as she pulls humongous radishes out of anything she can stand on, including ice and ultra-thin floating platforms.
Snake manages to produce a range of rocket launchers, grenades, trip mines, and a surveillance CYPHER from absolutely nowhere. Otacon points this out in an Easter Egg Codec conversation. When Snake mentions Link's ability to carry a ton of inventory (and how he thinks it would weigh him down), the conversation ends on something to the effect of:
Snake: Gear is only useful when it's used at the right time and place. Just lugging a ton of it around doesn't do you any good. Otacon: I, uh... I wouldn't be talking if I were you, Snake. Snake: What's that supposed to mean? Otacon: You tell me, Mr. Utility Belt.
There's also Mario's cape, DK's bongo's, Kirby's sword, hammer, and any weapon based powers he picks up, Olimar's Pikmins, King Dedede's army of Waddle Dees, Doos and Gordos. But the ultimate example has to be Wario who can pull out a motorcycle. And then eat it. And then pull out another. Rinse and repeat.
"Mr. Game & Watch": Every single one of his attacks has him pulling out something, except for his Final Smash and one of his taunts.
One of Link's custom attacks lampshades this:
Giant Bomb: Pulls out a huge bomb that causes a huge blast. (Where on earth is Link keeping it?!)
In Amazon: Guardians of Eden, when picking up a pole, the narrator tells you, "You pick up the pole." And when picking up a ladder, the narrator tells you, "You put the ladder in your back pocket."
In Kingdom of Loathing certain adventures involve the character "using an item he didn't know he had; and no longer has after" to either solve a problem or ward off an attack.
The message you get when you summon a Boba Fettucini in combat: "pew pew pew!" <name> shouts excitedly, drawing a laser pistol from some spiritual dimension of necessity. "kill kill kill! pew pew pew!".
In the Disgaea series, one of Rozalin's signature moves involves reaching into her rather large gown, whipping out a minigun and shoot down enemies.
Halo: In Halo: Combat Evolved and Halo 2, whenever the player has two weapons, only one weapon will appear on the character (in this case in his hands) while the other weapon does not seem to be anywhere on the player, as the player's armor does not seem to have any visible pockets or straps for weapons. From Halo 3 onward, both weapons appear on the player, one in the player's hands and the other either on his back or on his thigh. This can be used to the enemy's advantage as it makes you easily identifiable as a bigger threat if you carry a big weapon (for example, fittingly, the Gravity Hammer). That said, we still have no idea where the player keeps all their grenades and ammo.
The first three generations of Pokémon games originally gave the main characters backpacks that hold a finite amount of items, with excess items having to be deposited in the main character's PC storage box (which itself may qualify). Pokémon Diamond and Pearl abandoned this by giving the heroes backpacks with infinite storage space, even though their backpacks don't look any bigger than the ones previous characters had. Though all of them can somehow hold things as large as bicycles. The bicycle thing is handwaved in later games by describing the bikes in question as being collapsible. (Even if this were the case, one would be hard-pressed to fit anything else into a pack of that size once the bike was in there.) In the games, items are found in Poké Balls. Some people take this as an explanation for the Bag's large storage space and how item storage works.
In Sonic Unleashed, Exposition Fairy Chip is able to produce endless amounts of chocolate, each bar bigger than he is, out of thin air. Furthermore, he offers one to everyone he meets.
Lampshaded in Sonic Generations when Classic Tails asks where Classic Sonic puts all the rings, to which Modern Tails cannot answer, having not asked himself.
Which is odd, since Tails is a huge user of this trope himself, even more than Sonic. At times, he'll pull a toolbox from nowhere (large enough for him to use as a chair), a remote-controlled robot the size of his head, and, most frequently, a never-ending supply of bombs (whether cartoony or shaped like rings).
Zone of the Endershandwaves this trope by means of suggesting that 'metatron', a principle material in the series, can expand, contract, and generates pockets of spacetime called Vector Traps more or less at the user's will. This makes it a convenient place to store a vast array of weaponry, which you accumulate throughout both games.
The unique element abilities of many, manyChrono Cross characters thrive on this trope.
In Day of the Tentacle, when Doctor Fred walks out of one door, then minutes later after Bernard solves a puzzle appears out of a different door when the only way to get from one door to the other is to pass through the room Bernard has been in the whole time, he asks "How did you get over there?" without receiving a response. This was a sort of Lampshade Hanging on how older adventure games often wouldn't keep track of where NPCs were continuously, but have them just appear in response to events and not be able to be found otherwise.
Similarly, the player characters in Day of the Tentacle show off their dimensional pockets on numerous occasions. Particularly Bernard, who pulls a crowbar out of his pants pocket a few times, and stores away a considerable length of hanging rope by giving it a yank and holding his pocket open while the entire thing just falls in.
The Space Quest series of adventure games has various jokes about all the inventory being carried around.
In Space Quest II "You take the plunger with you, boy these adventure game hero's know how to pack"
A particularly humorous lampshade is hung in Space Quest VI: The Spinal Frontier, when Roger attempts to pick up an optional (and useless) 2x4 piece of wood. The Lemony Narrator bets that you can't fit it in your pants, then goes on to theorize that they are truly bottomless after you prove him wrong.
Also lampshaded in Space Quest III: "You take the ladder and jam it in your pocket. Ouch!"
Space Quest V also makes mention about how all the items you carry do nothing to aid the unimpressive bulge in your pants.
The King's Quest series (produced by Sierra, like Space Quest) Lampshaded the character's unlimited inventory in the official hint books by including the question "Where does my character keep all that stuff?" The answer: "The same place Superman keeps his street clothes when he flies."
The 2015 game actually runs with this, having Graham explain that his cloak was hand-made by his mother with tons of pockets; any time he adds an item to his inventory, he does it with a Cape Swish (this trope is still in effect, as Graham can store objects like full-size mirrors in there). This was also true of Superman during The Silver Age of Comic Books. Episode 2 takes this to its logical conclusion, with Graham storing another human being inside his cape.
Grand Theft Auto: San Andreas: when CJ and Ryder go out to steal ammunition from various sources, CJ notes that the truck they're driving appeared from nowhere and the fact that it wasn't on Ryder's 'curb when it showed up. Ryder tells him to chill. He says his homies brought it over during the previous scene and that CJ didn't notice because Ryder's homies are like ninjas.
Monkey Island series. The series protagonist, Guybrush Threepwood carries all inventory in his pants with no visual indication of taking up any space or hindering movement. This is often done deliberately for comic effect (multiple times he is shown stuffing or dropping an object equaling his height in length with relative ease)!
Used in Monkey Island 2: LeChuck's Revenge, when talking to a fisherman whose pipe was constantly being shifted from his mouth to his hand while he gestured. At one point of the conversation, he ends up with a pipe in both mouth and hand, and one of the possible lines at this point is "Hey, where did that second pipe come from?" If chosen, the fisherman quickly reverts to his default sprite, looks around shiftily, and replies "What pipe?"
In the first game, at one point, Guybrush is thrown into the sea with his feet tied to a heavy object. How can he survive? By picking up said heavy object and stuffing it into his pants. Since the object is now in his inventory, it no longer weighs him down, and he can swim up to the surface.
In Simon the Sorcerer, Simon puts everything he picks up in his pointy hat, including a ladder.
In Leisure Suit Larry 2: Looking for Love (in Several Wrong Places), Larry wonders how he's going to pick up a glass which stands half his height and is full of liquid besides. The game then says, "Ah, shucks! This isn't real life... just an incredible simulation!" and lets him stuff it into his pocket "along with everything else." The scene in which he shoves the vessel into his leisure suit jacket is even animated.
In the Discworld games, where Rincewind can only carry two items whereas the Luggage (being a Bag of Holding) can carry an unlimited amount.
Parodied in the bow stringing animation in Runescape, where you are seen pulling a bow out of your pants, stringing it, then putting it back.
In all of the Crash Bandicoot games that have the Bazooka. This cannon, that is larger than Crash himself, is kept in his back pocket.
Most games where you can put away your weapon have this. Also, sometimes the weapon is longer than the character.
A specific example of this is in Silent Hill 2, where James can at one point pick up a massive "Great Knife" which is about as large as he is tall. He can only barely move while dragging the giant thing behind him, and actually swinging it is a painfully long process - put it away in your inventory, though, and he can run around happily as normal.
Used in Zork: Grand Inquisitor, when in the middle of the eventure, AFGNCAAP pulls out a huge vacuum cleaner. Dungeon Master Dalboz remarks "Just where were you keeping that?"
In a truly fantastic scene, Matt Engarde manages to pull a glass of cognac from Hammerspace while in prison just for the purposes of swirling it evilly.
Less awesome but still notable is Maxamillion Galactica's ability to throw a bunch of cards from his apparently bare hand. While this is reasonable given that he's a magician, after the sixth or seventh time you wonder exactly how he got all of them up his sleeve.
Trucy from Apollo Justice is also a magician, and we are told in the second case that she has been known to pull a tyre out of her underwear.
When he's prosecuting, coffee slides into Godot's hands from out of nowhere.
Throughout the series, the BoundWeapon spells essentially allow the caster to pull a powerful weapon from hammerspace and use it for a fixed duration. This has been variously explained as either you're creating the weapon out of pure magicka, or you're temporarily summoning the weapon from Oblivion (similar to standard "summon" spells). In several games, there is also a "Bound Armor" spells which is the same effect, but summons and equips temporary armor.
The only real limit on what you can carry is your "Encumbrance" limit. You can have an infinite number of items on your person (including numerous large weapons, sets of armor, thousands of arrows, enough food to feed an army, enough books to fill a library, gallons of potions, literally millions of gold coins, etc.) and none of it will show unless you specifically equip them. (Essentially, your inventory is a Bag of Holding minus the "Bag" itself.) As long as the combined weight of the items is below your Encumbrance limit, you can move around without issue. (And Skyrim changes the system so that you can't run while over-encumbered, but you can still walk. You can carry literally billions of tons of items and move, albeit it at a snail's pace.)
The Nameless One, is a hulking brute of a man; he has twenty inventory slots that can fit sledgehammers, human skulls, books, and other sundry items. He manages to lug around his massive arsenal of knives, Eldritch Tomes, spare arms and so on despite wearing nothing more than a loincloth and animal-bone belt.
Morte, a supporting character, has the same twenty slots as the Nameless One has. He's a floating human skull. Hammerspace is the only reasonable excuse. (The question of where his inventory was kept was actually a frequent joke among players.)
The scantily clad Annah, not-quite-so-scantily clad Fall-From-Grace, the Modron Nordom (living cube on stilts for the heathen masses), and Ignus who is on FIRE, yet still manages to store scrolls.
In zOMG, the Kokeshi Dolls are small animated toys that wander around Zen Gardens, apparently unarmed. But if you make one of them angry they proceed to pull an giant bladed fan from nowhere, then they throw it at you. Then they pull another one out of thin air and repeat the process.
In True Crime: Streets of L.A., when threatened the pimps (dressed like pimps) take out a small gun, and the hookers (dressed like hookers) take out large rifles...
Similarly in Total Overdose, when confronting a mobster in a jacuzzi with two bikini-molls, they all draw assault rifles.
The Keyblade from Kingdom Hearts, as one of its inherent abilities, can truly be summoned out of thin air (or out of someone else's hands) whenever its wielder needs it. According to Word of God, later installments even added an effect for each time Sora drew his keyblade from Hammerspace. Other weapons in the series like Riku's Soul Eater, which technically IS a Keyblade, also seem to operate on this principle.
In Kingdom Hearts: Birth by Sleep, the three protagonists have entire suits of armor in hammerspace. These are summoned by a sharp rap on their shoulder guards, and apparently replace the character's normal clothing. Terra's armor in particular shows a very nice view from behind, especially compared with his usual hakama (massive pleated Japanese pants). The Organization's weapons can be summoned like this, too.
Every character that sees combat is to some level a magician, and that teleportation is really common in the series.
The Pandora Directive, like most adventure games, ignores this most of the time, with items you click on going into inventory magically. At one point you do this with a 15-foot bamboo pole and are carrying it around in some unknown manner. However, parts of the game are full motion video, and the designers decided to have a little bit of fun, so when you need to use the pole, you are treated to the video of Tex Murphy absurdly pulling a 15-foot pole out from under his trenchcoat and then using it.
Resident Evil 2. Mobile hammerspace. Excess inventory is stored in various identical crates around the game world. No attempt is made to explain how putting an item in a box in a cop office allows it to show up in the sewage substation office. The "stash" in Diablo II functions in much the same way. In the case of multiplayer mode, this results in two or more characters accessing different inventories from the same box.
Found in Resident Evil 4, for any weapon wielding zombie. If you shoot their weapon out of their hand, they will pull out another one, no matter how many times you do it. Interesting case with Leon's attaché case. The case actually has limited space and has to be upgraded to carry more stuff. However, the case is never visible during gameplay (and you still run into a rocket launcher along the way).
Justified or hand-waved in a scene in Tales of the Abyss wherein Jade pulls his spear out of nowhere to ward off a surprise attack. Luke asks him where the spear came from, and he replies that he uses magic to keep it in his arm.
YukariYakumo, from the Touhou series, possesses/has access to a literal Hammerspace in the form of the her "gaps", tears in reality which she uses to travel and store/transport any item she desires, most notably several grave stones, enemy projectiles, traffic signs, and a train.
While SakuyaIzayoi is far less proficient, she uses her ability to mess with space-time to manifest her own Hammerspace pocket in which to store her ludicrous amount of knives, also using her power to stop time to retrieve them. (Some fans have stated that it's the same knife, being in multiple places at the same time.)
SuikaIbuki's treasured magical gourd, which never gets empty of sake. It's sometimes speculated what would happen if someone ever managed to set fire to its inside. This was explained in one of the official manga about the 3 fairies: Her gourd is soaked in the extract of a newt-like creature that produces an incredible amount of sake from a little bit of water.
Tomb Raider certainly fell under this. OK, so Lara can hold her signature pistols in her hip holsters and she carries her two handed weapon by attaching it to her backpack, but whenever you switch out weapons, like the Uzis or the Shotgun, the weapons occupying the space before it just magically vanish to make room for the new weapons drawn. One could argue that her backpack carries everything, but it seems silly how Lara can stuff 6+ guns with extra bullets, medi-packs, and flares in that tiny backpack.
Furthermore, Lara's hammerspace is such that any items collected in the games merely have to be placed in the general proximity of her backpack to be stored - not once do we see her actually place something inside her bag. This is referenced in the film, where keen-eyed viewers will see Angelina Jolie do the same thing with a piece of the triangle.
In the game Battle for Wesnoth Hammerspace is invoked frequently, and this is indeed acknowledged by the developers.
In The Pink Panther: Passport to Peril, a number of things can be carried by the Panther in pockets that he just opens in his skin/suit, and that can hold everything from a bag of chips to a fishing rod, a katana, a cup of coffee (still hot) and a live, termite-stuffed anteater.
It get's even more extreme in the sequel, The Pink Panther: Hocus Pocus Pink, in which he is able to put a complete Mammoth in his pocket (although he does require the help of a clown to do so).
Mega Man protagonists can hold and pull out a suspicious number of tanks and other miscellaneous items considering they're all in spandex, with no pockets to speak of.
They also regularly shoot objects from their Mega Busters that are larger than could possibly fit through the aperture, including sawblades, bombs, and a boxing glove (?). Justified in that proper scale would be too hard to see.
Rush and Eddie could be considered mobile Hammerspace, in that they can fit objects that shouldn't, by rights, fit inside their bodies.
Lampshaded in the second Ratchet & Clank. The commentator for arena battles occasionally questions where Ratchet is carrying his weapons.
In Naruto: Ultimate Ninja Storm, Ino Yamanaka's ultimate attack includes her taking out poisoned bouquets from behind her. Where she gets them is questionable, she doesn't have back pockets.
Lampshaded by Valve on one of their fake websites for Team Fortress 2 which offers, among other ridiculous services: "Lower total loadout weight by providing your staff with Hammerspace Technology (patent pending) to keep supplies and tactical items out of the way, yet still within reach."
The Engineer's Sentry Gun proves a most curious example. It starts off the size of a toolbox, expands and builds itself, can be upgraded two more levels beyond its first form (with two of any other weapon, be it massive minigun or puny pistol), and holds more than its visible share of ammo. On command, the sentry gun can reduce itself to the size of same toolbox. The toolbox itself comes from Hammerspace, while the subsequent levels of compaction are probably best explained as "Wrenchspace".
Taokaka from BlazBlue can store multiple items within the sleeves of her coat, including (but not limited to) her trademark metal blades, a bowling ball, fish bones, a different set of serrated blades, apple cores, baseballs, books, a Kaka clan child (the throwing of which earns you a Trophy/Achievement) and dinner set among other things.
Noel Vermillion is no exception to this rule, given the way she summons Arcus Diabolus: Bolverk, as well as her Zero-Guns, Fenrir and Thor, which both disappear after use.
The DLC character Platinum the Trinity is a shining example of this. Her Drive attack allows her to summon a variety of items, such as a frying pan, a paper fan, a 16 ton hammer, a giant kitty, bombs, missiles, and a bat.
The referee during the speed slice event in Wii Sports Resort. He pulls a bunch of random items out of nowhere (and all of them are huge) for you to slice, such as bread, sushi, candles, screens, bamboo, watermelons, oranges, diamonds, cakes, eggs, and the electronic timers used for power cruise event.
Frustratingly done in Limbo of the Lost where Captain Briggs can store stuff like coffin lids and bear traps in his pants but won't pick up things like boots or a coat unless he has a bag.
Jess from Mana Khemia: Alchemists of Al-Revis has a handbag, frequently Lampshaded, from which she can pull anything, of any size, of any dimensions, at any given time. Including other characters. And yet, I bet she still can't find a tampon when she needs one.
In City of Heroes, every weapon, whether on a hero or villain, is stored in hammerspace. The animation of pulling it out involves the character reaching behind his back and the weapon materializing out of thin air. This can range from a pair of knives (reasonable) to a war mace almost as tall as (or taller than) the player
And those few characters who do have a weapon visible will inexplicably draw a second, identical weapon from Hammerspace.
In Left 4 Dead The Tank is capable of pulling a sizable chunk of concrete out of the ground, regardless of where he is, such as a metal walkway.
The Gorn do this in Star Trek Online, where orbital bombardments also work anywhere.
In Left 4 Dead 2 players can now replace pistols with melee weapons such as bats and swords and chainsaws. The downside is you lose your pistol sidearms. Yet if you get incapacitated, you somehow manage to whip out a pistol to blast the infected with whilst on the floor.
Some of the Mortal Kombat characters have weapons that they don't always carry, including Shao Kahn's hammer and Kitana's fans, as well as every fighter in most of the 3D games.
The most recent games go out of their way to either have the weapon be on the character's person, or use effects to imply that the weapon is some form of concentrated energy.
In Fallout 3, the Pip-Boy must come with some sort of pre-war super-storage compartment because the thousands of bullets, half a dozen outfits, sack of drugs, The Terrible Shotgun and all those holotapes must be on the Lone Wanderer's person somewhere.
Not just thousands; you can carry an arbitrarily large number of bullets because ammo has no weight. Averted in Fallout: New Vegas, where (in Hardcore Mode) ammo does have weight.
World of Warcraft gives characters lots of bags to store stuff in, but the question of how, physically, a person would lug around entire sets of armor, dozens of weapons, hundreds of potions, etc., remains unanswered. An attempt at justifying this was actually made for pets and mounts, whose inventory items are supposedly devices used to summon them rather than the creatures themselves; otherwise you'd be carrying around a half dozen horses (or kodos!) in your pack in addition to all those weapons. Also interesting is the graphical display of weapons, which do actually appear on the character's back or belt, but when swapped (say, for a wand or ranged weapon) vanish back into hammerspace. Occasionally the flavor text for particularly incongruous items will refer to this, including some large boulders which the player has to collect an entire set of which say, "Probably best not to think about how you're carrying several of these."
Mists of Pandaria averts this in a couple of quests by giving you an NPC ally to carry heavier items like barrels of beer, and visibly so. Sometimes the items you collect normally will show on your character model (usually on your back) as well, and in a few instances such as a scenario where you collect stolen brew you can even become encumbered by carrying too much at once.
In Punch-Out!!, how exactly can Soda Popinski's soda bottles fit into his very small speedos?
Eternal Sonata has the typical Hammerspace for weapons, but no one knows where Beat's camera comes from. He just turns around, rummages through the air, and...poof! There it is!
MadWorld's central character Jack has what appears to be a telescopic chainsaw attached to his bionic right forearm. Where the blade (and more importantly, the chain) of said saw goes to whenever it retracts is unclear. Rule of Cool clearly applies.
Toontown Online has the Gag Pouch, which soon becomes the Gag Backpack. The Gag Pouch holds 20 gags, and will soon upgrade to 50 gags once you get the Gag Backpack. What's funny is that you never actually see it. You're just told how much stuff is inside of it, and it gets even funnier when you store life-sized trains and opera singers inside of it.
Much like the Kingdom Hearts example above, everyone in Dissidia Final Fantasy can produce their weapon of choice from thin air at any time, complete with a flash of light when it appears. This gets a little ridiculous when you play as Bartz, who constantly summons and dismisses the other characters' weapons as he fights. The sole exception seems to be Firion, who is explicitly shown to be carrying his sword, axe, bow, daggers, etc. on his person at all times.
In every Final Fantasy title before Final Fantasy VII, playable characters are never shown wielding their weapons, and they only appear when using the "Attack" command. This might be fine for daggers or even swords if you pretend the sprite has a sheath too small or blurry for human eyes to see, but where exactly do they hide a 5-foot-staff?
Any Final Fantasy title that has no limits on how many items you can hold. Even if each character is holding 33 of everything, that's still a whole lot of everything.
Lightning Returns: Final Fantasy XIII is the first aversion in the series, restricting Lightning to six slots for restoration items, though that number does increase with progression through quests.
More recent Final Fantasy games that make no provision whatsoever for where the heroes put their weapons outside of battle.
Especially curious is Cloud's buster sword, which sometimes appears on his back, even on the field. A vast majority of the time, it's just pulled out of Hammerspace though. There's also no provision for how it actually stays on his back.
Concept art indicates that the Buster Sword is held on through the holes in the blade slotting over magnets on the back of Cloud's clothes.
In some cutscenes of Final Fantasy VIII, Squall reaches behind his hip and takes out his sword from out of nowhere. It is implied from the animation that he's drawing the weapon from a sheath, but there's no sheath on either the character model in-game or in the actual CGI cutscenes. Squall also has a Gunblade Trumpet Case he is never seen using.
It was one of the later titles that brought back visible shields in the form of bracers and guards. These are presumably snugly tucked away in Hammerspace once the battle ends.
If the characters swap weapons during battle, they seem to literally do this - they just reach off to one side a little, the old weapon disappears, and the new one appears. Makes as much sense as anything given the number of weapons you can end up carrying by the end of the game.
It does this with all ranged weapons. Players reach behind their backs and a gun, crossbow, or boomerang materializes. Even longbows, which can be half the size of the player avatar, are not visible unless they are currently in use. Humorously, while the ranged weapon is in use, melee weapons disappear.
There's also no explanation as to how players can carry something as large as a bookcase in their immediate inventory other than "Moogle Magic."
Noctis of Final Fantasy XV is sustained by this trope. His primary power is the ability to summon items from seemingly nowhere, which he uses to store not just weapons, but mundane items like fishing poles and whistles. He can even manipulate this ability to teleport himself by throwing his weapons, making him the series' first Hammerspacemancer. It's also the first time in the Final Fantasy series that this trope has been Justified.
Joshua of The World Ends with You can drop an Ice Cream truck on you, seemingly from out of nowhere, by dialing a number on his cellphone.
In Bayonetta, the main character pulls a massive chainsaw from the hammer space behind her to do a punishing move on the flying stingray-like enemies.
Somewhat justified in Mass Effect - thanks to omni-gel and omni-tools, mods for weapons can be constructed on the battlefield and installed with minimal difficulty. This doesn't account for larger items like weapons and armour. Mass Effect 2 dealt with the problem by removing the inventory altogether.
A very minor, almost unnoticeable example in the second game: no class other than Soldier actually carries the pistol visibly on their person. It is drawn from the same place as the SMG (the left hip), but the weapon there is always the SMG, and if you are wielding the SMG, the pistol is not seen.
The first game averts this by showing every character with their four guns (sniper rifle, shotgun, assault rifle, and pistol) carried in various places, despite the fact that nobody except Ashley (and sometimes Shepard) can use more than two of them effectively. Not completely, though. When you change your inventory, the new guns/armor appear out of Hammerspace to replace the old.
Justified in Borderlands - the player is pulling things out of a subspace compartment. The tech involved also explains why you're limited to specific number of items (which varies, depending on how many Backpack SD Us you've acquired) rather than weight.
Metal Gear Solid and the sequels tend to do this. Weapons and items just appear from midair when equipped; including assault rifles and missile launchers. Interestingly, the series gradually got slightly less ridiculous about this; in the early games, weapons and equipment not actually equipped were treated as entirely nonexistent (particularly in MGS1, as its key cards were mentioned to be "Personal Area Network" cards that simply needed to be on someone's person to open doors, but which Snake couldn't get to work unless he was actually holding the right card). MGS2 still didn't have any sort of weight issues, but at the very least had the keycards actually work the way the game says they do. Starting from Snake Eater, the player still had a "backpack" that held all the items they picked up, but to actually use any of them they had to be moved into the active inventory, which was limited to 8 (5 in later games) guns and 8 other items, where they would weigh Snake down and effect his rate of stamina usage.
The character Malin from The King of Fighters series takes out a hammer which its size is larger than herself out of nowhere for her leader desperation move. God knows where and how she is able to pull that off. Same goes for Oswald and his seemingly infinite deck of cards on him.
Dragon Quest series mostly avoid this. Most games' battle systems are first person view and each character only carry 12 items including your equipment. Since VI and the remakes, you have a bag that stores limitless items and equipment outside of battle. Your wagon and ship probably helps when traveling across continents with your inventory.
[PROTOTYPE] is sort of this in almost every way about Alex. Groundspikes and its devastator version that would require several Mercers worth of biomass. Possibly averted in that Alex appears to have an exceedingly high density (as evidenced by such things as his ability to bring cars to a complete stop by jumping on them or the fact that the pavement cracks whenever he lands after jumping off a roof).
Minecraft's grid inventory allows the player to carry (and swim with!) up to 2304 cubic meters of stone, or 44'470 metric tons of gold, which equals 1.7 times the weight of the Titanic.
Even more if you consider the fact that chests can store just as much as the inventory. You can tear down a mountain and carry half of it with you, then stash the other half in a chest that takes up less than a cubic meter of space.
Taken Up to Eleven with the Ender Chest. Any item that is placed in one of these chests can appear in another Ender Chest no matter how far away the chests are or they're in completely different dimensions! On top of this, even if every Ender Chest placed in the world is destroyed, the items will still be in the hammerspace of the chest once you make a new Ender Chest.
And if you carry an Ender Chest in your inventory...
Made even more ridiculous with the Shulker Box, which is like a regular chest but if you break it, it will hold all of it's contain inside, meaning you can carry entire chest worth of items within a single item slot. Meaning that you can carry absurd amount of stuff if you fill your inventory with Shulker Boxes, each filled full of items.
Deus Ex is a first person game, but it has mirrors, so you can watch yourself pulling knives, rifles, or even rocket launchers out of your sleeve. Also, the rocket launcher is so big that you can barely move when wielding it (without training). Good thing you keep it in hammerspace.
In the Animal Crossing series, your character can store up to 16 items in their inventory. This can include tools like shovels and axes, clothes, fruit, insects, and fish. It's especially ridiculous in the last case, as you can casually stuff something as big as a whale shark into your pocket. The furniture is handwaved as somehow being able to transform into a small leaf, but nothing else gets any mention.
What's even more odd is how the animal villagers do this. Notably, they don't wear pants, so seeing one stuff a whale shark or a grey wrasse into their "pockets" is odd. This also hasn't been explained.
In the newest installment of the Super Smash Bros. series, the Animal Crossing villager can use this as a special attack, allowing him to stow away even immaterial objects like Mario's fireballs or Samus' charge shot to pull a delayed Catch and Return.
The Sims store various devices in Hammerspace, among them mops, screwdrivers, money and hand puppets.
The Sims 3 takes this above and beyond with the inventory system carrying everything from seeds to guitars to whole cars.
In addition, there are items that don't show up in inventory, like fishing rods, snake-charming horns, cell phones, and ghost-hunting guns that appear when one is doing the appropriate action. These things come from the Sim's back pocket (or somewhere else depending on how you look at it.)
In Psychonauts, you can fit a stop sign, a dowsing rod, a gun, a plunger, a radio helmet, and several jarred brains inside a backpack roughly the size of your own torso.
The Dark Forces Saga makes plenty of use of hammerspace, but it's particularly blatant in Jedi Academy when the player character has to place demo charges - three large barrels of explosives appear out of nowhere. And there are always multiple charges to set...
Dark Souls has an unlimited inventory even without the Bottomless Box. Also, the only weapons that can be seen are the ones you currently have equipped, with the changes in equipment occurring out of thin air. The most blatant example, however, is the Lordvessel from the first game, a MacGuffin you retrieve midway through the game. When your character places it on an altar in a cutscene, we see that it's a metal bowl larger than the character is! Many players' reaction is "Where the hell have I been carrying that!?"
MapleStory uses this heavily as any given character can store numerous items away. Inventory space is limited to a number of given slots, broken down by category - equips, use items, etc items, "setup"(often limited to chairs and holiday decorations) and Cash Shop items. However, multiple copies of the same item can stack into one slot (with the exception of the equips - even identical copies of the same gear count as separate items) menaing that it's possible to have 100 potions or 1000 arrows in one slot. Extra slots are often added during job advances and additional slots can be purchased in the Cash Shop. Provided a player is willing to spend the money, they can expand storage so much that it may be impossible to reasonably fill it.
The MOTHER series almost subverts this. It IS used, but each character has a limited inventory space of 16 items, regardless of the item's size (an ATM card takes up as much room as a baseball bat). This limit includes items that each character has equipped. After accounting for a weapon, two pieces of armor and one protective item, your inventory per character is reduced to only 12 free spaces and certain items have to be carried throughout the game by at least one character. Using healing magic over potions is common in this game.
NetHack has the plain old Bag of Holding for hoicking stuff around, but large boxes and chests are this trope; they can hold infinite amounts of anything (troll corpses fit in quite nicely, one of the best ways to get rid of the damn things; they'll even fit dragon and giant corpses). About the only things you can't put in a chest are yourself, pets (although Schroedinger's Cat can start off in one) and the genuine Amulet of Yendor.
APB Reloaded, especially the Criminals; each one carries a primary weapon, secondary weapon, 2 grenades, a handcuff key, brass knuckles, a slim jim, a crowbar, , a spraycan, bombs, a camera, a netbook, a supply crate, a gas can, a battering ram... Plus, the ability to carry 50 small objects (packages, harddrives, cellphones, etc). Enforcers have similar equipment, minus the gas can, bombs, and crowbars, but include a snub nose and handcuffs (for arresting), and paint sprayer.
Xenosaga characters have access to armored fighting suits (which double as small spaceships) called AGWS which they can summon at any point during a battle, completely out of nowhere. Two of the main female characters, Shion and KOS-MOS, use weapons in battle which are larger than they are and which they summon through some sort of dimensional folding process. (KOS-MOS is a battle android who looks like a teenaged girl: her weapons are *inside* her and fold out for use.)
Karnov gives no indication of where Karnov keeps the various items he can carry around. One of these items is a ladder several times Karnov's height.
The Matrix: Path of Neo has this justified in some levels, like the govt. lobby where you know they have harnesses on. Later levels, aren't so justified, as Neo's wearing a tight cassock with no room for a weapons harness underneath, but, weapons just appear and disappear from his hands. Again, it is The Matrix so maybe it is 'magic' after all.
Sarah from the white chamber is able to fit a barrel of explosives, a whole human corpse, and many other odds and ends into her tiny jacket pockets as she moves around on the wreckage of the ship.
Splatoon: When switching into their squid forms, the Inklings have the ability to instantly store whatever weapon they were using. Which gets slightly ridiculous when said weapon is an enormous roller that's wider than the Inkling is tall. All of their special attacks are also pulled out of Hammerspace.
In Ryzom, players can carry up to ten eight-foot long automatic grenade launchers (called "Autolaunchers") in their inventory, alongside whatever armor, other weapons, and raw materials they may have acquired in their journeys, without any sort of noticeable difference, even if you're a Tryker, which is half as tall as everyone else.
Marvel: Contest of Champions has this used by champions who have weapons as part of special attacks but not normally visible on their model. Winter Soldier and Punisher top the rest by pulling out two handguns and a bazooka for their third special. Originally played straight by Drax, who would pull his knives out for this third special attack, until an update made him hold them all the time.
In Planet Explorers, a player's inventory has room for hundreds of items, and could concievably hold an entire fleet of flat-packed airships, ready to be deployed at a moment's notice.
Discussed, Rabi-Ribi has an achievement that comments on how much your inventory would weigh with 100% item completion. ( About eight kilograms.) Not to mention the main character's weapon of choice is literally a hammer, pulled out of Hammerspace upon attacking.
Most of the hunters in Evolve seem to have access to this. While a few of them have a reasonable amount of equipment, the rest have no excuse for lugging around several full sized guns, hundreds of rounds of ammunition, hours worth of jetpack fuel, and other bulky equipment. Bucket has a justified version with how he manages to pull a nearly unlimited number of turrets out of his chest cavity, since his torso contains a material assembler.
Averted in X-COM and its immediate sequel: you have a jigsaw puzzle of fitting items of different sizes in very restricted spaces.
Ashley of the Another Code games is also fond of this, holding a considerable amount on her for a teenage girl with nothing but pant pockets.
This is actually lampshaded in the second game, Another Code: R. While Ashley is noticeably pulling items from a fanny pack on the back of her jeans (which in itself doesn't make sense, since it's far too small), whenever she does this during the standard conversation set up (in which you only see Ashley, close up, from the front), the animation makes it like she is literally pulling items outta her ass. Considering how it's set up, as well as other instances throughout the game where they take light-hearted jabs at "silly" aspects from point-and-click adventure games, this was very likely done on purpose as a bit of Self-Deprecation, and to poke fun of this trope in general.
Kyle Hyde is also prone to carrying loads of items, especially towards the end of his games. His noticeable moment is in Last Window, when he stuffs the entire contents of a cardboard box into his jacket pockets and carries it around to try and sell to people.
Mario Kart games have it where all of the characters have this trope when they obtain an Item.
Special mention goes to Link, added as part of the first Mario Kart 8 DLC pack. When Link does a boost jump or trick, he somehow produces his sword and raises it. He can also produce the Triforce when performing a trick off of an anti-gravity ramp.
BloodRayne, in the first game, has fairly standard hammer space, though her active weapon does actually appear on her person. However, there's a cheat code that shows all currently-owned weapons to appear on her character model, and it's a good reminder of why Hammer Space is such a common trope, since she looks absolutely ridiculous with all of those weapons hanging off of her.
Ys VIII: Lacrimosa of Dana is especially egregious about this as three of the playable characters have weapons at least half their size that vanish completely upon being sheathed.
Characters' weapons in Brawlhalla are stored in magic glowing swords that occasionally spawn onto the stage, which then transform into anything from knives to hammers to rocket lances. In addition, some characters have signatures that knock terrain up from the floor, such as Koji kicking up a floorboard or Kor punching rocks out of the ground, but these abilities can also be used in midair. There's also the question of where Caspian keeps his extra knives and bombs, where Xull keeps his beartrap, where Isaiah stores his drone and rifle, etc.
The janitors in Two Point Hospital stash all of their supplies inside their coats: brooms, vending machine supplies, garbage bags, and comically-oversized ghost-sucking Dustbusters.
Some of the customers' objects in Cold And Flu Invasion, such as the scooter and the balloon, seem to appear out of nowhere when they get healed.
Lampshaded in Versus Umbra, when Adrian thought Michael would put a parachute in his infinitely deep pockets, together with weapons, gadgets, and lunch.