In zany comedies, when a villain attempts to break down a door by charging at it, sometimes the best tactic is to simply open it.
The trick is to do it at the exact moment when they would have rammed it. When it works, the villains cannot attempt to stop or even slow down, but just keep going at full speed. Then they usually run into any number of traps prepared to bring them down — or out another door on the far side of the room.
This move becomes even harder to dodge when the door is made of two fully independent parts.
Compare Door Fu, which is when a character tears off a door (or picks up a torn-off door) and uses it as a weapon. Contrast Tae Kwon Door; for when you want to use the door to cause damage to your enemies instead of letting them through.
- Urusei Yatsura: After finding out that Lum and Ataru will be spending the night together, Lum's Stormtroopers and Mendo decide to break down the door. So on the count of three they charge, only to have Ataru open the door and Lum open the window on the opposite side of the room.
- One Piece: Sanji, Franky, and Usopp are on the sea train Puffing Tom, which is loaded with government agents. After they've sent most of the agents soaking by disconnecting cars, one of the few remaining agents charges at the door — only for Sanji to open it and cause him to fall into the ocean. "Oh, you wanted out, sir?"
- This is taken Up to Eleven in the first episode of Symphogear AXZ, where two characters aboard a helicopter play double-Door Judo with an antiaircraft missile.
- In Tintin in the Land of the Soviets, Tintin opens a door for a bad guy trying to charge it at full speed. The bad guy hits his head on the far wall, and Tintin closes the door in the face of the others following him.
- Calvin and Hobbes; Calvin will do this occasionally to avoid getting tackled by Hobbes when he comes home from school. Circumstances usually arise that prevent him from capitalizing on this (example: the first time he did this, he walked off happy in his success while ignoring that Hobbes had recovered and was charging right back).
- In The Emperor's New Groove, Evil Chancellor Yzma gets a ridiculously complex Door Judo treatment from Pacha's family, involving Offscreen Teleportation, a beehive, a floor waxer, a feather pillow, and a conveniently placed birthday party.
- In Zootopia, As one of the Big Bad's ram minions does a full-on charge against the locked door of the subway car, Nick uses this against him so he goes charging into one of his fellow minions knocking him out the window and getting stuck there in his place.
- Played with in Toy Story 2 (and not just in it being essentially Vent Judo) during the "Use Your Head" bit. The toys run at the vent with Rex as a Battering Ram, unaware that Woody had already unscrewed it and left it loose. They pass right through and wind up in a dogpile inside Al's room. Inverted during the Animated Outtakes, where the vent had not been unscrewed prior to "filming".
- The Boys of Paul Street: Two gangs of teenagers, the Paul Street gang and the Red Shirts, are brawling. Some of the Paul Street boys have barricaded the shed. A bunch of Red Shirts grab a log, determined to break down the door. But it's all a trick, as when the Red Shirts come barreling at the door, a Paul Street boy yanks it open. After the Red Shirts come spilling inside, the Paul Street boys dart out the door and lock the Red Shirt boys in.
- Peter Sellers in A Shot in the Dark. He charges at a door just as it opens, and his momentum carries him across the room, out the opposite window, and into a river.
- Jungle 2 Jungle. Tim Allen's business partner is trying to talk his daughter into coming out of her room. Tim shows up, with his son on the other side of the door. Tim suggests that they both try to knock down the door. In the bedroom, the son tells the daughter "Baboon here. He make peace," and opens the door. Tim and the partner run through, crash through the window and the balcony, only to end up in a crumpled heap on the ground below.
- In Watchmen, Rorschach uses this against the SWAT team at Moloch's apartment, throwing the door breacher completely off balance as he swings his sledgehammer into the floor. The level of shock and disarray this causes in the rest of the SWAT team seems exaggerated, though.
- Done for humor in Cannonball Run II, a case of when the door isn't opened from the other side. When JJ (Burt Reynolds) and company infiltrate the Pinto Ranch to rescue the Arab Oil Sheikh and discover the room he's in, they decide to break the door down, which he, Victor (Dom De Luise) and Vendebaum (Sammy Davis Jr.) begin charging at. Problem is, Blake (Dean Martin) accidentally pushes the door open just as the former trio run right through it, and thus end up running through the room into the far end with a bonk.
- Done ridiculously in The Pirate Movie. On their first run at the door, the pirates use their ram to ring the doorbell. On their second run, the butler opens the door for them, leaving them to charge into the mansion. The pirates then carry the ram up a spiral staircase for no reason before dumping it on the second floor.
- Inadvertently done in The Grand Budapest Hotel. Agatha, fallen out a window and hanging for dear life. Zero, one floor too high, needing to go down to the correct room in order to pull her in. The correct room, unfortunately locked and with a "Do Not Disturb" sign. Zero, yielding to politeness and knocking desperately, before less politely trying the doorknob, and finally charging the door. The guest, opening the door in answer to Zero's knock, in time for Zero to charge right through and out the window, to hang beside Agatha.
- Up the Chastity Belt: When Sir Sir Braggart de Bombast's men attempt to break down the door of Lurkalot's workshop with a battering ram, he opens the door so they crash into the wall opposite. Before doing so Frankie Howerd breaks the fourth wall to say there is no way such an old joke can work.
- David Drake did a variant on this in his book Patriots. The heroes tricked a Benedict Arnold Expy into being filmed dramatically charging through a door marked "command center." He found out too late he was running into a very large open-pit latrine, and just managed to scream "Holy sh--" before falling into it. It was deep enough that he was completely submerged in liquid crap. That gave them blackmail evidence.
- A confined Dexter uses this tactic in Dexter in the Dark to get free and find Astor and Cody before they become sacrifices.
- Dirk Gently does this in The Long Dark Tea-Time of the Soul when he is barricaded in his kitchen against a marauding eagle.
- In one of the Confessions of Georgia Nicolson books, Georgia suspects her mother of having an affair with the builder, and skips school to spy on them from the other side of the door. She is caught when they open the door and she falls through it abruptly, forcing her to pretend that she had just been sent home sick from school.
- Used twice in the comedy TV series Get Smart. Once when Maxwell Smart and 99 are trapped in a corridor with two villains trying to break down the doors on either side. Our heroes open each door in turn so they knock themselves out. CONTROL agents know this as the "Double Door Deception Trick." Another time, Smart and the Chief are breaking into a cabin from opposite ends, when CHAOS agents simultaneously open both doors. Smart and the Chief run past each other and out the opposite doors, and two CHAOS agents shoots at them - missing and shooting one another instead.
- Jeeves and Wooster has one moment where Roderick Spode charges a door just as Jeeves opens it. Jeeves (as usual) is completely unsurprised by the large man charging past him and making a loud crash, and simply greets the other man standing outside with his trademark "Good evening, sir."
- In an episode of It's Always Sunny in Philadelphia, Frank buys a foreclosed house from the bank but the family refuses to leave. So the gang shows up with a SWAT battering ram to break down the front door. This trope ensues (of course), leaving Dennis to fall flat on his face in the front hall. Subverted moments later though when the gang, feeling cheated and unsatisfied with this turn of events, decides to just smash and kick the door down anyways from the inside.
- Dad's Army: In "Museum Piece", the museum caretaker defeats the platoon's attempt to break down the museum door with a Battering Ram by opening the doors so they charge straight through.
- Hilariously inverted in Drake & Josh. In one episode, where the titular stepbrothers are hiding inside their English teacher's bathroom to hide from said teacher's vicious dog while house-sitting, Drake realizes he left his cellphone in the living room and has Josh open the door for him to run out very quickly to circumvent the vicious dog in the living room. When Drake tries to run out, Josh forgets to open the door, causing Drake to crash hard into it.
- In the Kingdom Hearts II world Beast's Castle, Donald falls flat when Belle opens the door Donald was about to break down.
- To get past the first little area in LEGO Harry Potter: Years 5-7 Battle of Hogwarts, you must raise a gate a Giant is attempting to break down. Not only will he crash through the next, much flimsier door on the other side of the small courtyard, but he will trip over the low wall just beyond the door and fall, presumably to his death.
- Looney Tunes, repeatedly.
- Bugs Bunny is particularly fond of this trick:
- The ultimate example is probably Bully for Bugs, which sets up Bugs' Final Strike against the bull.
- The 1942 Bugs Bunny cartoon "Hold the Lion, Please" has Bugs do this to Leo the lion— and in an especially ridiculous way, as the door is set in an upright frame in the middle of the jungle. Now Leo isn't the sharpest knife in the drawer, but he clutches the Idiot Ball extra tight, as he's prompted to ram the door after Bugs dangles a key in front of him— around the door frame— and then snatches it away.
- Happens in the Bugs Bunny short Mississippi Hare, where Bugs and Colonel Shuffle each pull this gag on the other in a row, and then Bugs pulls it for a second time, but this time he's opening the door to the boiler room of the ship.
- Also happens in Hare Way To The Stars with Bugs Bunny and the huge green aliens created by Marvin the Martian. Similarly to Mississipi Hare, they open doors for one another and the aliens end up falling to space when the last door leads nowhere.
- In Red Riding Hoodwinked, Sylvester and another (unnamed) cat do this at the same time, one at the front door and one at the back. Sylvester stays in front to build a boulder slingshot; the unnamed cat goes in back to grab a log for use as a Battering Ram. You can guess what the end result is.
- Sylvester also uses this trick in "Mouse Divided," against a cluster of cats using a larger log as a Battering Ram. They end up running all the way to the top floor, then fall out the window into a well.
- Bugs Bunny is particularly fond of this trick:
- A rare example where the door isn't opened by someone on the other side: in an episode of Danger Mouse DM attempts to knock down a door with a runup while Penfold leans on a lever on the wall which opens the door.
- In Hanna-Barbera's Top Cat, Benny once goes on a cruise, prompting the rest of the gang to tag along. At several points, Officer Dribble, the ship's captain, and a counterfeit artist try to barge into the cabin... only to end up running right off the ship, having to cling (unsuccessfully) to the side of the hull.
- In the Tex Avery short "Little Rural Riding Hood", Red Riding Hood does this to the wolf, who runs all the way to the second story of the house and falls out the window.
- Mega Man pulls this off in "Terror of the Seven Seas" with a pursuing Guts Man. While running down a hallway, he sets it up by closing several doors in Guts Man's face before opening the final door that leads to a maintenance shaft.
- The climax of the Tom and Jerry short "Professor Tom", Tom tries to ram the front door down to get at Jerry. However, Tom's pupil opens up the door (and gets Squashed Flat by Tom), then Jerry sets up an innertube across the backyard patio so that Tom will be sling-shot back through the doors and into the mailbox.
- The Mad Doctor has this get pulled on Mickey Mouse near the end. It sets up strapping him to an operating table for the climax.