Sword Sparks

The Sword Fight: man against man, clashing steel with force enough to sever a limb.

And sparks. Lots of sparks. When two swordfighters cross swords, the force of their collision will send up sparks, showing just how powerful, sharp and deadly the crossed swords are. In more extreme cases where the blades remain together as the two fighters push against each other, the cutting edges may not only spark but actually visibly heat up until they glow, usually to indicate the combatants are both ridiculously strong. This can occur even if one combatant's weapon isn't actually a sword.

In reality, it is possible to strike sparks with a sword, but it's quite uncommon. Generating a spark by hitting another sword is all a matter of angle and friction, not of strength or sharpness -- in fact, a rough piece of steel is much better at generating sparks than a trued and polished sword. Stage performers will use flints on the part of the blade closest to the hilt to achieve this effect consistently.

Sometimes this is used to imply a character has a kind of quasi-magical ability without going too fantastical with the show.

See also Audible Sharpness and Sinister Scraping Sound. Compare with Bullet Sparks.

Anime and Manga

 * Used copiously in Inuyasha, both in swordfights & when the title character sheaths his ludicrous BFS. The act of cramming the gigantic magical sword into a normal sized scabbard kicks up so many sparks that he has to wear fireproof pajamas to avoid immolating himself.
 * Technically the sparks when he sheathes the sword are actually the sword transforming-the sword takes two forms, a shabby katana, and an incredibly gigantic sword that's meant to evoke the fang of his demon father (mostly because it was made from the fang of his demon father). Enticing the sword to transform from the small useless form into the big powerful form was actually a major plot point early on in the series.
 * In Mai-HiME, Mikoto's sword Miroku generates enormous quantities of Sword Sparks when she drags its tip on the ground... which is almost all the time, since it's practically bigger than she is. She has to build up speed to swing it.
 * When two Devices clash in Magical Girl Lyrical Nanoha, they will send up sparks. Best seen in the opening of the second season, where Nanoha's staff and the handle of Vita's hammer produce lots of sparks during a Blade Lock.

Sufficiently strong shields like those used by Yuuno or Wolkenritters will produce massive amount of sparks when attacked as well (which breaks weaker shields instantly). If they're really strong (thank you, Stone Wall Ferret), it's device-on-shield lock with even more sparks. Later, when most of the major members of the Band of the Hawk were battling several members of the Bakiraka in a dark tunnel, Judeau puts out their lights and then uses sparks from several different weapons to reveal where their enemies are as they're attacking.
 * Justified in Code Geass; the Humongous Mecha-sized swords are usually made of vibrating Phlebotinum, if not outright microchainsaw-like in operation.
 * Specifically, the Britannian swords are vibro-swords, while the Black Knights use chainswords with heated blades.
 * Slightly averted in One Piece, during Zoro's battle against The Dragon to Sir Crocodile, Mr. 1, who can create any metallic weapon from his body, including drills. When Zoro strikes them, he's genuinely surprised that sparks kick up and wonders for a moment how fast they're really going.
 * Many sword fights (or with any edged weapons) in Fate/stay night. Granted, they are all Mana-charged armaments, so Power Glows are inevitable.
 * Shannon and Chris have a sparktastic sword-on-axe duel in the first episode of Scrapped Princess (see image above).
 * And then they have another one in a canyon made of glass. Sparks, shards, tricks with reflections, the works.
 * Sometimes happens in Bleach. When Ichigo fights Ulquiorra, sparks fly when Ichigo's sword strikes Ulquiorra's arm. Ulquiorra didn't bother using his sword the entire fight.
 * In Rurouni Kenshin, a.k.a. Samurai X, a Big Bad lampshades this trope when he explains that his sword has oil in it, using the sword sparks to set it on fire.
 * Gundam 00 not only has the regular Sword Sparks, but took it another level by having intense energy discharges every time someone clashes blades, and even in a Blade Lock.
 * Of course, beam sabers don't quite fit this trope, as they aren't solid swords, and Gundam Exia's swords are lined with GN particles, so yeah.
 * Used occasionally in Afro Samurai, but most noticeable in Resurrection during Afro's fight with the Number Two. Their blades spark every time they connect, even producing sustained sparks during several Blade Locks. One particularly forceful parry on Afro's part has sparks shooting everywhere for several second as the Number Two's sword travels up the length of his (Afro's) sword, with a sound effect like a lightning generator.
 * In Berserk, Godo states he enjoyed the sparks he made whenever he was working on something, which makes Guts notice how they're likewise something he sees a lot of while doing the only thing he knows to do in life.
 * Turns up in Soul Eater. One example is when Crona fights first Maka and then Stein. Soul gets effortlessly cut and knocked around by Ragnarok. When Death Scythe Spirit turns up, the only effect Ragnarok has is some sparks.
 * Necessary in Claymore, where there is a lot of sword-fight, but the sword are so fast that they are invisible : the sparks are a visual way to tell the audience what is happening.

Film

 * The first sword fight scene in Pirates of the Caribbean: Curse of the Black Pearl has sparks coming from it... but since Will Turner is attacking Jack with a red-hot poker, striking it against something that doesn't burst into flames would produce sparks.
 * The lightsaber duels in Star Wars sometimes strike sparks, though these being energy blades it's somewhat justifiable. It might also be from minor bits of scenery being heated white hot in an instant.
 * In Blade, Frost and Blade have a high-speed swordfight. Both Blade and Frost having vampiric strength, Blade having fed recently and Frost, the sparks are not unexpected.
 * In the final battle of Ultraviolet, sword sparks are used to light oil.
 * Lampshaded in Robin Hood Men in Tights, when Robin looks at the camera and exclaims "Shocking!", just after the Sheriff's sword makes sparks from striking a stone column.
 * The Highlander films take this to near-obscene levels, with explosions of sparks unrivaled below the point of foundry work at every metal-to-metal contact.
 * To acheive this swords were attached by cables to car batteries. The cables can be spotted in some scenes.
 * And metal-to-concrete, metal-to-stone, metal-to-wood... There were even a couple of occasions where the blades sparked when the Flynning fighters missed each other's sword
 * X Men Origins Wolverine. Logan's claws have always done it some of the time, but in this movie, it's taken to unprecedented heights.
 * Numerous sparks fly in Wolverine's battle with Lady Deathstrike in X 2 X Men United. Notably, since sparks are made by little bits of metal flying off the blade, this should be impossible in an adamantium-on-adamantium duel, since adamantium is invulnerable.
 * In Hook, the first two times Hook and Pan's swords meet emit enormous, ridiculous sparks for no reason. After this they disappear and are never mentioned again.
 * They do this in Blades of Glory, kicking the air and meeting each other's skates to produce sparks. This was intentional on their part, due to Rule of Cool.
 * Happens a few times during Shu Lien and Jen's fight in Crouching Tiger Hidden Dragon.
 * Curse of the Golden Flower had an entire ly gratuitous fight sequence devoted to this.
 * The final fight in Ninja Cheerleaders features this prominently, although the sparks in question are electric, not pyrotechnic.
 * Crossing swords with the Slayers in Krull causes this. Sweet, enormous red ones. Actually, looks like little lightning bolts.
 * Happens constantly throughout a lot of the fight scenes in An Empress and the Warriors.
 * During the final fight in Advent Children, Cloud and Sephiroth fight against each other in a dark building. The only legitimate source of light is the abnormally bright sparks their swords make while fighting.
 * However, the swirls of light are presumably caused by pent-up energy of a Limit Break that Cloud is holding back. This is a reasonable assumption since shortly after this fight scene, he does indeed use a Limit Break, and the blue swirls are no longer seen after that until the end.

Literature

 * The Codex Alera series has this being a trait of those able to use metal furies to empower their sword-fighting; the Sword Sparks are actually color-coded with individual colors for each character.
 * Fridge Brilliance:
 * In The Wheel of Time, whenever a Power-forged weapon strikes a similarly-forged weapon, blue-white sparks fly.

Live-Action TV

 * Pretty much every episode of Highlander. According to the special effects director, the effect was achieved by connecting one sword to an electric line. At least among fans, this is generally considered a Power Glows effect of the franchise's Applied Phlebotinum.
 * Andromeda: "And Your Heart Will Fly Away". Dylan is attacked by a swordfighter whose sword strikes sparks against everything: the deck plates, Dylan's lance, even the plastic control panels (perhaps an overlap with Explosive Instrumentation).
 * Tokusatsu generally has this trope all over the place, with sparks indicating a direct hit on the opponent. This includes Kamen Rider, Super Sentai and Power Rangers. The Power Rangers are often said to "bleed sparks" because of excessive use of this.
 * Sparks happen with any hit, including ridiculous examples like a Ranger being thrown through a stack of cardboard boxes with a ton of sparks.
 * A particularly silly example comes in Kamen Rider Kiva when, during the Dogga Hammer's debut battle, Wataru/Kiva drags the hammer along the ground, kicking up sparks every couple of seconds.
 * Wrath from Kamen Rider Dragon Knight likes to scrape his swords together before a fight, creating sparks. Apparently, it indicates absurd sharpness.
 * Eliot and a Russian mob thug generate sparks while fighting with crowbars in "The Three Card Monte Job" of Leverage.

Theatre

 * The live-action Medieval Times shows use titanium blades to cause lots of sparking during the fights. For those unfamiliar with Medieval Times, it's an American dinner theater restaurant chain that holds a joust during your meal.

Video Games

 * The Knights of the Old Republic video games produce streams of them, with both lightsabers and metal swords.
 * In the first fight between Dante and Vergil in Devil May Cry 3, the two of them lock swords so hard that not only do sparks fly, their weapons start glowing red-hot from the sheer energy being produced.
 * Raiden and Vamp did this with knives during their final battle in Metal Gear Solid 4.
 * Almost every single cutscene fight in Sengoku Basara, which will inevitably involve a Blade Lock, causes the weapons to spew forth sparks like grinding irons. It's a wonder the characters don't get their face burnt off.
 * This is used as a gameplay mechanic in The Legend of Zelda Four Swords. Two or more Links have to slash their swords together to create sparks and light lamps.

Web Comics

 * Used briefly in Gunnerkrigg Court. During a practice spar, Jones deflects a sword with her face. Instead of bleeding, a spark comes off her cheek.

Western Animation

 * Parodied in a classic Felix the Cat cartoon, where Felix battles a Pirate captain, and their swords not only spark, the blades start glowing, eventually fuse together and burn a hole through a wooden floor when dropped.

Real Life

 * In fact swords do strike sparks quite often.
 * If one isn't careful with the speed and angle, not only are sparks likely, but sometimes may result is blades "welding" themselves together. Hilarious the first time it happens, not so much when you have to spend ages fixing the blades once you've yanked them apart.
 * Some enterprising effect artists will wire up a sword to a battery to produces a sparks, however, that will make accidentally poking your co-star (or more likely yourself), that much more painful.
 * A fencing foil, when the tip wears through, can strike sparks during coordination training that involves pinning a falling glove to a wall.