Door Judo

In zany comedy, 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 do not to 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.

Anime & Manga

 * 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.

Films -- Animation

 * In The Emperors 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.

Films -- Live Action

 * 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.
 * In the movie Jungle to 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 the Watchmen film, 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 2, a case of when the door isn't opened from the other side. When JJ (Burt Reynolds) and company inflitrate 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 DeLuise) and Thunderbomb (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.

Literature

 * 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."  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.

Live Action TV

 * Used in the comedy TV series Get Smart 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 the doors simultaneously so they run into each other.

Web Comics

 * Castle Heterodyne (the ultimate Ghost Butler) pulls this on Moloch von Zinzer in Girl Genius. The room on the other side of the door is... well, not there.

Western Animation

 * 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.
 * In one short, two characters do this at the same time, one at the front door and one at the back. The one at the front door has a battering ram. You can guess what the end result is.
 * 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.