Weapons Kitchen Sink

In certain kinds of stories, you want characters to have weapons. It's important: They need weapons to fight, their choice of weapon may reflect their personality, and it makes them look cooler.

The problem comes when you give The Hero a rapier, The Lancer a scimitar and The Big Guy a broadsword.

In real history, the development of swords in particular meant that each kind of sword had different uses. Broadswords, falchions and katanas, for instance, were designed for infantry to deal with their creators' versions of heavily armored opponents. Scimitars, cutlasses and sabers were for cavalry to cut down unarmored infantry. Rapiers, epees, small swords and the like became popular as both civilian self-defense and dueling weapons, and were rarely seen on the battlefield. Firearms and armor co-existed for a while (approximately three centuries), but eventually firearms made metal armor obsolete until the first practical bulletproof vests were created in the early 20th century.

In fiction, however, that goes right out the window. Scimitars and sabers will be used by unmounted people against straight swords, and it's almost a given that both combatants will be unarmored. A character in battle with a heavily armored combatant won't use a mace to smash in the armor and pulp the guy inside or even use a straight sword to stab him between armor plates; the fighter without armor will probably dispatch the armored fighter in a more exciting way. And of course, a Medieval European Fantasy might have the odd Katana show up in the hands of a really cool Badass.

A kind of Anachronism Stew. Justified by Rule of Cool. Some may try to Hand Wave it by having the weapons be more representive of a culture or nation rather than personality type, despite the clear impracticality of such a thing. Not to be confused with Swiss Army Weapon, which includes everything but the kitchen sink.

Examples of Weapons Kitchen Sink include:

Anime and Manga

One Piece: Many organizations, even armies, don't have a proper, "uniform" equipment. Among the egyptian-like members of the Alabasta army you can see polearms, katanas, zweihanders, morning stars and muskets.
- Actually, that example is an aversion. The organized Royal Army actually does have uniform equipment. The Rebel Army is justified in adhering to this trope, as they were specifically stated to have scrounged up weapons from wherever they could get them.
Ga-Rei Zero: Used to great effect; the Red Shirt uses machine guns that can shoot the supernaturals, the two main characters use katanas (and the titular Mons), and the other squad members use improbable weapons such as a gatling gun briefcase and a motorbike that engraves sacred runes on the street.

Film

The Matrix Reloaded, when Neo fought The Merovingian's agents. Considering that everyone literally grabbed weapons off the wall, and that they were fighting in the Matrix, it makes sense.

Literature

Christopher Paolini's Inheritance Cycle: Granted in that it is set in a different universe and culture.
Redwall: Where do we start? Everything from rapiers to tree-trunks, slings to ballistas, cutlasses to teeth-and-claws makes an appearance. And of course, the hero gets the blade of Martin the Warrior, a straight bladed double-edged sword in accordance with the usual rules. Everyone else gets whatever their species usually uses.
Justified in The Baroque Cycle. A very wide range of weapons come into the hands of various characters throughout the story, but everyone has a very specific reason to be carrying that type of weapon. When weapons are used, their appropriateness to the situation is almost always examined in detail. No one can ever accuse Neal Stephenson of not showing his work.
In the Hawk & Fisher series, Hawk uses an ax instead of the standard-issue police sword. Justified because he'd lost an eye and lacks the depth perception for refined swordplay.
In The Lord of the Rings each member of the Fellowship has slightly different weapons; justified by the fact that they come from different cultures and background, and each uses what he is used to. (Legolas the elf has a bow and a long knife; Gandalf has his staff and a long sword; Aragorn and Boromir have long swords; the Hobbits have short swords; Gimli the Dwarf has an axe.) All of the weapons are well fitted to skirmishing, too.

Tabletop Games

The Tabletop RPG Dungeons and Dragons is one of the biggest offenders in this particular category. Many worlds have lightly-armored characters wielding rapiers and scimitars alongside heavily armored guys with big whacking great swords and great axes. But then again, D&D's armor system makes heavily-armored fighters harder to hit rather than reducing damage (something that you can also do with light armor and a high enough Dexterity score), and the threat range on scimitars and rapiers make it easier to score a critical hit. The first edition rules did have "weapons effective against armor type" charts, but this was phased out in second and subsequent editions. As this editor recalls, chopstick vs platemail was a -10 modifier.
- This is actually a common misconception. Armor Class (AC) in D&D is not how difficult something is to hit, is how difficult it is to damage something—so, it's all the same to AC if you dodge blows or you have tough-as-nails armor. You still need to be good enough with your attacks for them to deal any damage, be it by getting past your opponents' armor or compensating for his nimble movements. In, fact the ability of a character to dodge attacks is actually applied as a bonus to their Armor Class, which is removed under certain conditions—which makes heavy armor very useful for front-liners, as the amount of defense you lose when you're caught off guard is less crippling than if you're wearing light armor and have a Dexterity of twenty hojillion.
  - It's functionally the same—the game doesn't distinguish between a blow that bounced off your armour and one that you dodged or that just plain missed. Also, if a blow does damage, it's the same damage range whether or not you're wearing armour.
    - When it's relevant to note that a blow simply made contact that was/might have been blunted by armor, 3rd Edition made use of the "touch AC" stat. It was mostly used for certain spells or attacks that involve grabbing the target rather than striking it.
- This is also noticeable with canon characters in the various game worlds. For example, in the Forgotten Realms, Drizzt Do'Urden fights with two scimitars. Artemis Entreri fought, for a long time, with a saber and dagger (he eventually got a straight-bladed sword that was more heavily enchanted). And so on.
  - In their defense, the oddness of these choices was noted. A lot of Drow are ambidextrous and Drizzt is supposed to be an epitome of this. Entreri was, through extensive training, just about on par with Drizzt, and at least he was wielding a light weapon in his off-hand.
Most fantasy games feature this due to their D&D ancestry. Palladium Fantasy. Warhammer Fantasy Role-Play, Anima, and the Riddle of Steel all follow this trope.
Certain modern era action games and cyberpunk games will feature a more modernized version of this, where anachronistic melee weapons, small personal defense firearms, and military hardware suited to bringing down a corrupt third world regime will all be given equal time and consideration on the weapons list.
GURPS: Dungeon Fantasy doesn't even bother with pretending that this doesn't happen, players are given access to all weapons from TL 0 to 4 because that's how the genre works. Also flamethrowers...
Eon has everything from humungous two-handed swords, all the way down to thin little rapiers. Granted, you rarely see them in the same geographical area; you're more probable to encounter light weapons where people don't wear as much armour, such as on the high seas, or with isolated cultures that haven't had the need to develop heavier weaponry. When it comes to the players themselves, the unforgiving and detailed combat system keeps them in check, with light weapons being almost completely forsaken in place of spears (!) or broadswords, as any hostile encounter is a potential death-trap if you're not completely sure of what you're doing, and heavier equipment helps even the score.

Video Games

The Elder Scrolls games include Katanas, wakizashi, tantos and ~~Orcish~~ Samurai armor along with early Medieval armor, claymores, longswords and sabres. Rapiers are absent however. According to the backstory, what we would call the Asian weaponry—tantos, wakizashis, katanas, and dai-katanas—are from the Akavir continent and exclusive to the Tsaesci (one of the four races of Akaviri known). The explanation of the Samurai suits is trickier: the Orc country Orsinium was allowed to exist during the rule of an Akaviri Potentate which may indicate inspiration. Blades armor and weaponry are based on Akaviri designs. The armor resembles Roman Lorica Segmentata, while the swords consist of Katanas.
Warcraft, especially World of Warcraft, is also pretty guilty of this. For the most part, it doesn't even really matter which kind of weapon you are using, although a few classes can specialize in weapon types (and Rogues need daggers for Back Stab moves). But there is no inherent difference between an axe and a sword, other than the fact that not all classes can use both.
Most games in the Final Fantasy series basically select weaponry choices based on personality or an abstract battlefield role within their battle system, at best simplifying the attributes of a particular weapon style to fit. Somewhat averted in Final Fantasy X, which generally takes into account the need for different kinds of weapons for different kinds of enemies, but in a pinch, anything will usually work, just not as well.
- Gameplay and Story Segregation occurs in that respect in an unusual way in Final Fantasy X. The plot implies that Wakka's Blitzball, a thrown weapon, is best for use against aerial targets. In actuality, Wakka just starts with higher accuracy; ANY character with the same accuracy (and luck) stat would have the same chance of hitting a given target, whether they're using a blitzball, a sword, or even a doll.
Dynasty Warriors and Samurai Warriors brings new meaning to the Kitchen Sink part of this. It has a ridiculous number of weapons that have no right coexisting the way they do, varying from the improbable (flutes, fans, and children's toys), to ones that shouldn't be present given the setting (boomerangs), to the misused (chakrams being used primarily as melee weapons; Chinese dagger-axes being dual-wielded or thrown). But it's cool, so who cares?
Tales of Symphonia: Lampshaded somewhat where another character wields a ball and cup game. At one point, Kratos points out that Lloyd's weapon choice and fighting style—dual-wielded sabres—is wasteful and inefficient. Lloyd's response (paraphrased) was that he uses two swords to get twice the attack power bonus.

Lloyd: I thought if one sword had an attack of 100 then two swords would have an attack of 200 right?

In Phantom Brave, anything you can pick up can be used as a weapon, from sunflowers to starfish to werewolves.
- And then fused with everything else to combine spells, so you can end up with a sword that slaps like a fish or a pumpkin that stabs like a spear.
This was the point of Dead Rising. And, well, zombies.
Wanna play some Samurai Shodown? Then get ready to watch the Lady of War use her rapier to parry a huge stone pillar. Or perhaps you'd like to watch Andrew Jackson block a shot from a sledgehammer with his rifle? Or maybe a Catgirl using a boomerang to block a polearm is more your flavour.
Soul Calibur features character using all manner of historical and even fictional weapons.
Fire Emblem: These games go back and forth on this one. The trope is played straight in the notion that there are many, many kinds of weapons from swords, axes, lances and bows, many of which are nonsensical (one of Eliwood's better weapons throughout FE 7 is a rapier that does bonus damage against calvary and heavily armored units). This trope is subverted in the sense that most weapons have a bonus for attacking a certain type of unit or a certain weapon style in a weapon triangle.
Unwritten Legends is a particularly egregious example, in that just about every pre-internal-primer cartridge weapon you can think of probably has at least one example in game.
Averted in Dragon Age: Origins, apart from the elvish curved blades most every sword or dagger is a medieval European straight blade, and if you are going to be fighting heavily armored foes you probably are going to be using a mace or warhammer.
All 75 potential recruits in Exit Fate have a unique weapon, often named, and while they usually fit a more specific trope than Improbable Weapon User, the tropes in question vary wildly. What other game allows practitioners of Chain Pain and Throw the Book At Them to fight in the same party as a Death Dealer? Then again, most of the really ridiculous weapons are used by characters who have a low attack power...
Team Fortress 2 originally mostly used unique variations of Standard FPS Guns and this trope only applied to the melee weapons, which included things from knives to bottles to bats to bare fists. The unlockable items have since plunged headlong into this trope, with things like bows, crossbows, cans of soda, sandviches, flags carried around with a bugle, shields, boots, tranquilizer guns, flare guns, remote controls, lasers scavenged from crashed alien delivery ships, and jars of piss.
In Rune Factory 3, various townsfolk who accompany you to battle will carry a cutlass, a katana, a double-headed battleaxe, twin shortswords, a two-handed broadsword and a war hammer, respectively. And this isn't even including the magic users or or the Improbable Weapon Users.

Webcomics

Sluggy Freelance: During the "Oceans Unmoving" arc, the Space Pirates use swords, throwing hatchets, flintlock guns, grenades, switchblades, and even laser weapons. Justified since the residents of Timeless Space are literally from different points in history, some coming from the present, others the far future, and others the distant past. Also justified when it's found that most of the 'pirates' are geeks of one sort of another, who took the opportunity of being stranded in timeless space to play pirates, and so picked whatever weapon they felt was cool.
In A Beginner's Guide to the End of the Universe, the army of the future people use completely random weaponry (from shotguns to halberds). Justified in that they get all their weaponry from the miscellanopod trees, which give them entirely random stuff. Meanwhile, the members of the evil cult that opposes them are able to use Reality Warper powers to spontaneously manifest any weapons or equipment they want.
In Order of the Stick, the soldiers of Azure City are supposed to be a japanese/chinese fantasy counterpart. Yet, their weaponry include katanas (fine), western-style halbeards and large towershields.

Web Original

The Whateley Universe. Some of everything in this package. Fey now has a magical mithril scimitar. Bladedancer has a magical jian made of jade. Tennyo has an antimatter lightsaber. Lancer is a flying brick and can extend his super-strong field over small things, so he has paper swords... which can cut through concrete. And then Winter Term courses include a 'special topics' class, so this gets really gets crazy. Phase is working with a tactical baton, Chaka is learning the meteor hammer, Aquerna gets a pair of kama, Shroud is working with a dozen knives (simultaneously), ...
Comes into play at points of Tales of MU in Callahan's class, Mixed Melee, in which the main character, variously armed with a dagger, a pitchfork, and a quarterstaff, has to spar against Gloria, a Knight Templar with a sword. The lack of parity is at times remarked upon as well.
Chaos Fighters are this as a whole, with modern and medieval weapons appearing simultaneously. It gets egregious when bronze coin daggers, scimitars and katana are added. This is not counting the double weapons and mix and match weapons.

Western Animation

In Rollbots, most people who are onvolved in fights have some kind of special weaponry; Botch has a Hard Light grappling hook, Manx has Energy Balls, Macro has a giant Wrecking Ball, the Kei'zatsu have Hard Light handcuffs which coat the entire body... and Spin has a collapsible sword.