Blade Lock

At any given time during a Sword Fight, expect the two blades to lock together.

This usually works best if the swords are crossed horizontally between the combatants, who stand close together and push against the clinch, each trying to knock the other off balance. It can also be done in a knife fight, with grabbing wrists or fists instead of locking blades. If a character is Dual Wielding, they will place one blade behind the other in a (very unsafe) attempt to use both arms for leverage, rather than, you know, just stab the other guy while he can't parry or dodge and get it over with (Being able to do this is one of the main advantages of dual wielding).

This is the ideal moment (since Talking Is a Free Action) to address the combatants' mutual issues with some confrontational dialogue, or to toss out taunts or threats. Or to let slip with a Groin Attack, since the other can't really defend against it. Or simply stand there, stare at each other menacingly, and bulge some biceps. If both combatants are super-strong, or sometimes even if they're not, the blades might grind against each other with sparks or even visibly glow.

Technically, this is called tsuba zeriai in kendo and anbinden or simply "bind" in the medieval German longsword tradition, where both parties try to gain a position for an attack by jockeying around so that the 'strong' (the half closer to the hilt) of one's blade is pressing against the opponent's 'weak' (the other half); the kinds of attacks that can be launched from this position vary from thrusts and snapping cuts around the opponent's blade to trapping (including the famous Groin Attack), grappling, and tripping/throwing movements. Also called "corps à corps" (body to body) in fencing/stage combat.

Anime

 * Magical Girl Lyrical Nanoha does this with the characters' staves, and any other device that could be swung around as a melee weapon.
 * Vampire Hunter D features a blade lock between one character's sword and a vampire's wing complete with sparks and heated blades.
 * Happened a few times on Rurouni Kenshin. When this happened to Yahiko, he did the smart thing and kicked Gohei in the nuts.
 * When this happened between Kenshin and Saito, Saito shoved Kenshin against a wall and nearly managed to push the blade into Kenshin's throat.
 * One Piece. Most dramatically used in the Zoro and Mihawk fight, where Zoro, who wields three swords, is completely denied a hit by a basic knife.
 * Happens in the openings of Gundam SEED Destiny
 * In one of Naruto's first story arcs, Zabuza and Kakashi locked blades for a minute or so. Zabuza had a great carving knife of a sword, bigger than he is. Kakashi had a kunai, a stubby dagger about as long as your hand. If the battle had stuck to the rules of real life Kakashi would now be "the Two-Fingered Ninja".
 * This also happens when Sai attacks Naruto out of nowhere. Sai takes advantage of this moment to question whether Naruto has any equipment.
 * Also happens in the Pain arc. Ebisu blocks Pain's chakra blade with the point of his kunai for several minutes.

Film - Animated

 * Happens several times in Advent Children. For example, in the battle (on motorcycles!) between Cloud and Yazoo, they lock blades; Cloud's BFS against Yazoo's Velvet Nightmare.

Film - Live-Action

 * There probably isn't a Sword Fight ever committed to film that doesn't use this trope.
 * Subverted in Robin Hood Men in Tights of all places. When Robin Hood and the Sheriff were in the middle of one, they talked for a bit and the Sheriff tried to use a knife.
 * Probably a homage to The Adventures of Robin Hood, in which Robin Hood and Sir Guy of Gisbourne similarly talk at intervals throught their duel; during a Blade Lock Sir Guy stealthily pulls a dagger out and tries to stab Robin with it. Robin being an honorable sort, but not Lawful Stupid, when the dagger ends up missing Robin's head, Robin runs Sir Guy through with his sword.
 * Or possibly to Robin Hood Prince of Thieves, when the Sheriff raises his blade for a killing blow on the prone Robin, who pulls out the Sherriff's own dagger (He had given it to Marian, who had then given it to Robin) and plunges it into his heart.
 * Parodied in Spaceballs, where Helmet and Lone Starr's Schwartz blades (akin to lightsabers) not only get locked, they twist up. "Shit! I hate it when my Schwartz gets twisted."
 * Subverted in Kill Bill Vol. 2. When the Bride and Elle lock swords in their final battle,
 * Frequently in the Star Wars films. Note that this is an unbelievably stupid idea, as the lack of a crossguard on most sabers would mean that if their opponent slid the blade up they'd probably lose half their hand, not to mention quite possibly having their lightsaber destroyed.
 * Obi-wan does exactly this to cut off two of General Grievous' arms in Revenge of the Sith.
 * Consensus appears to be that two lightsabers stick together when locked, preventing (or at least making difficult) that kind of move. Obi-Wan appears to twist his blade, rather than simply sliding it downwards.
 * Done in Streets of Fire with sledgehammers rather than swords.

Literature

 * Subverted in The Saga of Darren Shan. In one book, Darren gets in a sword fight with a vampaneze and tries blade locking. The vampaneze simply runs his blade down the length of Darren's and maims his hand.
 * Averted (hypothetically) in Tim Powers' The Drawing of the Dark. Ambrosius attempts to explain to the protagonist Brian Duffy, using Blade Lock as a metaphor, why epic magic is impossible when there's another powerful wizard of opposing alignment in the room. Duffy, a gritty old soldier, remarks: "I wouldn't just stand there straining. I'd knee the bastard and spit in his eyes."
 * Used in Lady Knight, though in this case it was glaive versus double-headed axe. Kel was smaller and already wounded, Stenmun had the advantage - until Kel did a leg sweep, knocking him off his feet so she could kill him.
 * Occurs during one of Princess Carline's fencing lessons in the first book of the Riftwar Cycle. Her teacher tells her quite flatly that she never wants to get in that situation in a real fight - the only people she'd be likely to end up facing in a real battle would be professional soldiers who would be much stronger than she is.

Video Games

 * Attack at the same time as your enemy in No More Heroes and you go into a blade lock, which you win by moving the Wii Remote in a circle. If you lose, you get hit; if you win, you can instantly hit the enemy with a Death Blow. Of note also is the real ending, in which Travis and Henry have a conversation while running down a whole city block with their blades locked together.
 * The Blade Lock is used as an actual game mechanic in the Star Wars Jedi Knight series of Video Games, in which you push against a "lightsaber lock" in an attempt to shove your enemy back and/or down and gain a free shot. Losing one against the tougher ones can instantly cause death. There are ways of breaking the lock, though. Probably the flashiest move performable from the lock is when one party has two lightsabers and manages to throw one to circle around their opponent and slice them from behind.
 * In Gungrave The three playable characters get in a tree way weapon lock, that being Grave's guns locking with Jujy's Blades and Billy's Guitar, and they all spark.
 * Similarly, there is a move in The Legend of Zelda: Twilight Princess called "chance" that basically initiates this. It's.
 * It's also used in Phantom Hourglass. Here the lock is won by scrabbling the stylus over the screen rapidly. Against a recurring miniboss, it's the best way to win, and it's also needed to stun the final boss.
 * Halo 3 has the "sword clash"; two people use the sword-lunge (usually a one-hit kill) at each other simultaneously, the swords will glance off each other, knock the players back from each other a bit, zap their shields, and (barring assistance from a teammate) they try it again; it usually turns into a contest of timing at this point, to see who can get their next attack off quicker and actually manage to beat their opponent. I suppose, if you mentally squint a bit, this could be considered blade-lock, as it does result in a temporary stalemate, but it doesn't fit the literal definition of the trope.
 * In the game Suikoden V (and probably earlier ones in the series too) during a one-on-one "duel" battle, your protagonist almost always gets in at least one of these, requiring you to mash buttons as fast as you can to push the opponent back until the lock is over. Note that at least in this particular iteration, the protagonist doesn't actually use a blade, nor do many of his opponents, and yet you still get the "weapon lock" showing up.
 * Your battle against Cowardly Boss Koji Shindo in Yakuza 2 has you doing this during the final phase of the battle, which takes place in a Japanese courtyard, when Yayoi throws you a sword to use against him.
 * Happens all the time in the Samurai Shodown series. It's (probably) the only way to disarm your opponent too; though it's a little silly when the claws disarm the giant beads.
 * Done with every possible weapon and a few impossible ones in the Dynasty Warriors series.
 * In the Samurai Warriors series, winning one of these results in the character pulling off a special combo against the enemy.
 * Also used in Dynasty Warriors Gundam, where they are resolved with Action Commands.
 * Happens at the end of a "boss" minigame in Wario Ware: Smooth Moves.
 * This is an ability in Super Robot Wars. A pilot with this ability in a machine with a bladed weapon has a chance to block another robot's blade attack. With the Blade Lock animation and everything.
 * Another Centurys Episode had this in games 2 and 3 when two machines with melee weapons tried to melee each other at the same time; the player has to mash the Melee button to break the lock and stun the enemy, or he himself will be stunned instead.
 * This tactic features prominently in Kingdom Hearts.
 * Even though he uses knives, Leon locks blades quite often when facing up against Krauser.
 * You can lock chainsaw bayonets with an enemy in Gears of War 2. Mash B to win.
 * Commonly seen in cutscene fights between Dante & Vergil in Devil May Cry 3.
 * Happens almost every single battle in Sengoku Basara, particularly if the two characters are rivals like Masamune and Yukimura or Motochika and Motonari. Sword Sparks are always present.
 * The third game introduces something like this combined with Flynning where characters start clashing their weapons against each other until one of them wins the duels.
 * Kirbys Return to Dream Land has a variation.
 * In Saints Row 2, this happens during the cutscene for the mission "Bleed Out". It also occurs in the Saints Row the Third mission "deckers.die".
 * Used in the game Dark Messiah, though there it's referred to as a "contest of might."
 * Beautifully subverted in the Deception trailer for The Old Republic, the main villain of the trailer momentarily locked his blade with the leading Jedi he was facing off with, whom immediately breaks the lock by turning slightly to one side, loosing his blade and smashing Darth Malgus in the face with the pommel of his saber hilt. Ala the counterattack described below in the Real Life section.

Webcomics

 * In Sluggy Freelance this happens between Torg and the Demon King.
 * Zokusho Comics: Shows up all throughout Clash.

Web Original

 * Yu-Gi-Oh the Abridged Series has one of these between Yami Bakura and Yami Marik in a parody of Star Wars.
 * This awesome video of a short Samurai Showdown

Western Animation

 * Danny Phantom where Danny and Vlad did this in one episode with katanas.
 * Avatar: The Last Airbender: The dual wielding Jet and Zuko have one during their Sword Fight in an Evasive Fight Thread Episode.
 * Older Than Television example... Felix the Cat in The Goose that Laid the Golden Egg. In sword-fighting, Felix and Captain Kid's swords lock together due to the blades actually fusing together due to the heat from the friction of the fast fight.
 * Optimus and Megatron do this on occasion with blades from their hands.

Real Life

 * This, called tsuba-zeriai, is extremely common in Kendo. However, due to reasons already stated above, there are efforts being made to minimise its use.
 * Conversely, in Olympic fencing, this sort of overdramatic parry sometimes referred to as a Hollywood parry or Star Wars parry. Students are reminded to stop looking cool, disengage, and stab him already.
 * The angle needed to parry an attack varies between weapons, but is almost always much less than the average person suspects. Fencing is a fast enough sport that even a hint of movement in the wrong direction can mean a touch against you; exaggerated movements will get you hit.
 * Can be Awesome Yet Practical if fighting Florentine in an SCA event, though, as this is about the perfect time to stab him with your dagger.
 * This is not something that one would aim to do in real fencing, however. One parries with the flat of the blade, since the sharp edge would get damaged from the strike, and there's no chance that either side will try to lean one another down; instant counterattack is the only rational response. One of the most common ones is to strike back with the sword's pommel, while still holding the parry with the blade, but there are numerous variations.
 * Use of the edge or flat in a parry is a matter of some ongoing debate, as most fechtbuchen specify when to parry with the flat suggesting this is not the standard approach. Further, practical testing shows parrying with your flat actually makes you WEAKER in the bind. Now, parrying to your opponent's flat with your edge provides quite an advantage of leverage in the bind...
 * Contrary to most sport fencing today, longsword fencing in the German styles practically required this. Combined with other techniques like using the pommel and guard as blunt instruments and surprisingly advanced grappling, this was practically the only way to effectively fight an opponent in full armor. The general strategy was to bind, smash or throw your opponent to the ground, and then make a thrust at the now (slightly more) exposed gaps in your opponent's armor. Several techniques involved putting one or both hands on the blade of the sword, for extra leverage.