So, you're running a top-secret facility, and the first thing you did was install nearly impenetrable blast doors. Once they're closed, nothing can go through.
There is only one flaw: they take time to close. Way too much time. Sometimes it seems that the "message" to close the doors takes its time to get to all of them as well; Door #1 will start to close, then sometime after that Door #2 will start to close, then Door #3 etc.
There are some real life examples that lend this trope some credibility. Of course, the doors are gonna need to be heavy and strong for protection. The water-tight doors on the RMS Titanic closed very slowly, with only the last foot or so dropping quickly, in order that personnel could escape the sections closed off alive. Some rather large and heavy doors also use high-torque hydraulics or electric motors to raise and lower, which are notoriously slow, having traded off speed for strength.
If this is done with vehicles and the escapee is being pursued, expect the pursuers to be unable to stop in time and crash into the blast doors.
- Every example mentioned in Indy Hat Roll.
- Averted in episode 5 of Kiddy Grade. When Lumiere closes all of the doors in an enemy spaceship, they snap shut before the bad guys even realize what's happening.
- Averted in Neon Genesis Evangelion, where the internal security doors of the Geofront, once activated, snick shut instantly, sealing corridors extremely quickly.
- Used with crazy timing in ElfQuest: The Searcher and the Sword, when two elves are trying to escape from crazed trolls. What's crazy about it is that it's implied that the elves had plenty of time to escape, except that the rescue party's entrance alerts their enemies, who then check on the prisoners, see that they're gone, and trigger the trap, leaving the escapees to vault through the door at the last second. Drama! Did I mention that this is all done with giant slabs of stone a la Egyptian tomb? Read up on the thrilling escape here.
- Done via a Dangerous Key Fumble in 10 Cloverfield Lane, as the door to the survival bunker requires unlocking several padlocks to open.
- Near the end of Entrapment: After the characters accidentally trip the security system, a wall of gates closes rapidly around them, but for some reason the door blocking the actual exit moves incredibly slowly, long enough for them to escape.
- The alien mother ship in Independence Day had a single triangular access opening that slowly closed after the heroes fired their nuke into the center of the ship. Naturally their spaceship managed to squeeze through while the pursuers all smashed into the closed door.
- In this case it's definitely justified as being slow as said doors are HUGE!
- Averted in Man of Steel, enabling the holographic Jor-El to use them in helping Lois Lane escape General Zod's ship. A female mook charges in with a hand blaster, only for a door to slam down knocking the blaster out of her hand so Lois can use it, and trapping the mook on the opposite side. Jor-El cuts off several other guards this way, when there's too many for Lois to shoot.
- The theater owner's bomb shelter in Matinee.
- Played straight and averted in The One, as Gabriel escapes the Police Compound, he ducks under one of these. However, his Police Pursuers also make it through (though one of the trucks wangs its lightbar on it).
- Screamers. The soldiers return to their bunker only to find it overrun by the killer robots. Fortunately the bunker door opens slowly giving them time to retreat to higher ground. However there are too many robots and they have to set off a tactical nuke to survive.
- Spaceballs parodies the below Star Wars example, the characters jump through a door closing from the top and bottom, and are caught by the troops on the other side. However once the captain comes in behind them and asks them to turn around it is revealed it was the stunt doubles that were caught.
- The doors also close very slowly until the heroes/stunt doubles jump through, at which point they snap shut.
- Star Wars: Some security doors act this way, while others close almost instantly. Generally, whatever is required by the plot. One door on the Death Star in A New Hope was closing from all directions at once, so Han Solo had to jump through the hole in the middle.
- This is in fact Lampshaded. One stormtrooper orders the blast doors closed, then after Han and Chewie escape, another says "Open the blast doors! Open the blast doors!"
- The first arc of the animated series Droids featured a landspeeder chase scene that used this trope, plus several others (like the Imperial Stormtrooper Marksmanship Academy) repeatedly and in quick succession. R2-D2 suggests it's a trap, and it turns out it is: Behind the last set of slow doors is a dead end and a bunch of guys with blasters.
- Terminator 3: Rise of the Machines, allowing Ahnold to jump under the door and hold it long enough for John and Katherine to crawl under it.
- The door to ENCOM in TRON. Lampshade Hanging with an Ad Lib from the actor playing Flynn: "Now THAT is a big door!"
- In WarGames, we see NORAD personnel walking in and out while a ridiculously thick metal door is closing. This is Truth in Television: The blast doors◊ of the Cheyenne Mountain Complex are 25-ton monsters of concrete and steel, and take about 15 seconds to close. They're on record as the world's largest hinged doors.
- Zygote. The Final Girl shoots the Body Horror creature pursuing her and (after a Borrowed Biometric Bypass) is able to open the vault-like door to the corporate safe room. However the creature then starts to rise again and shambles towards her as the door slowly closes...
- Averted in The Atomic Submarine (1960). A sailor tries to flee an alien spacecraft through a Dilating Door as it slowly closes, but he's not quick enough and gets his arm caught and crushed.
- Andromeda: The doors on the titular ship close at a reasonable pace, but the bigger, more important ones (such as onto the command center), have a design that allows one to jump through the closing door.
- Averted on Babylon 5. The blast shield closes quickly enough to protect C&C from an attack that had already been launched.
- Blake's 7.
- "Redemption" was filmed in a nuclear power station so a real-life version is used. A Red Shirt performs a Heroic Sacrifice because he has to stay outside to push the thick radiation-proof door shut.
- In "Pressure Point", Gan has a Heroic Sacrifice holding up a descending door long enough for the others to pass under.
- "Space Fall" has a variation; Blake tries to shut the hatch to an airlock transfer tunnel but it won't budge, and he gets shot and wounded by his pursuer. Then the Liberator blasts off and the hatch shuts automatically leaving his pursuer to be Thrown Out the Airlock.
- Buffy the Vampire Slayer did the "message" version completely straight when Spike was escaping from the Initiative.
- Doctor Who: "Dalek" has the door to the lower levels of Henry van Statten's bunker, which closes slowly as Rose and Adam run for it. Adam makes it, but Rose isn't quite fast enough, leaving her trapped with the Dalek.
- Subverted for a bit of Enforced Method Acting in the Firefly pilot; Nathan Fillion and Adam Baldwin were expecting the doors to Serenity to close more slowly than they did, resulting in minor panic as Mal and Jayne jumped through the gap.
- In the end credits sequence of Get Smart, Max leaves CONTROL headquarters and all the doors that opened in the Title Sequence slam shut behind him, except the last one. When Max goes to close them manually, they shut on his nose.
- Used on Lost: the blast doors in the Swan lower rather quickly; however, they don't all close simultaneously, which allows Locke to wedge his toolbox under the last door before it closes.
- Played with twice in the pilot episode of seaQuest DSV. In the first case, an undersea wildcat miner is attempting to escape corporate security after he infringed on their mining fields one too many times; he pulls off an Indy Hat Roll with his mini-sub by asking his buddy at home base to start closing the docking bay doors before he's through. The trope is played straight in the second case (and re-used as stock footage several times thereafter), as a crewman is seen jumping through the main "clamshell" hatch to the titular submarine's bridge as general quarters is sounded.
- Played straight, but also Truth in Television, in Stargate SG-1. Remember those ginormous blast doors at Cheyenne Mountain? Also, the Stargate itself has been stated by Word of God to stay open as long as plot dictates, which has resulted in more than a few Slow Stargates moments over the series' run. The "Iris" blast door on the Gate closes very quickly; so, of course, it often fails to close at all, or the enemy goes right through it somehow.
- Star Trek: The Next Generation: in "Relics", the Enterprise-D manages to fly through the closing space-doors of a Dyson Sphere, with the aid of a nice roll maneuver.
- Two appear in the second stage of Axelay, but you can use your guns to blast them open.
- Beyond Good & Evil has looter caves with Doors that instantly lower half-way once the spark reaches them, but slowly close past that point.
- In Chrono Trigger, your team has to escape a robot factory that you've just shut down. You just squeak by the first set of Slow Doors, but Robo has to hold the second one open with his body.
- Averted in Dirge of Cerberus: Final Fantasy VII in a minor scene where the WRO locks down against intruders; a redundant and somewhat impractical set of doorways down a corridor slam shut in quick succession.
- The Half-Life chapter "We've Got Hostiles" has fire doors that take forever to close. Luckily you set them off manually, meaning you can shut them behind you and cut off the hostiles creatures dogging you. It's only one way, but you can open it again, except for the Door to Before; the blast door you went through is securely shut.
- Opposing Force uses this trope with a blast door that's partially open, but slowly closes thanks to the G-Man, and you can't go under it (without noclipping).
- Some doors in the Marathon franchise, such as the Door to Before in Blaspheme Quarantine, and the big doors on Durandal's ship in the second game.
- In Mega Man Zero one mission requires you to sneak into a factory. if you're detected, the Slow Door starts closing. if you're not through it before it closes, Game Over.
- Possible Lampshade Hanging in Modern Warfare, where one computer controlled set of doors in one (timed!) mission open ridiculously slowly:
Griggs: Oh, you've gotta be shittin' me.
Capt. Price: Gaz, can't you make it open any faster?
Gaz: Negative, but you can try pullin' if it will make you feel better.
Capt. Price: Cheeky bastard.
- The Myst games play this trope straight, particularly in Riven and Uru.
- One small area in Penumbra requires you to flip a lever in a far off room which opens the exit door that slowly closes as you approach. The tension is greater if you didn't kill all the spiders.
- The games in the Prince of Persia series are full of Slow Doors. Prince of Persia does have one door in Level 8 that closes just too late for the player (and then is reopened by mus ex machina). The Sands of Time series somewhat subverts this - some of the doors close quite quickly, but can be passed using the dagger's time slowing ability.
- Star Wars Legends: In the game Dark Forces, on the level titled Gromas Mines, the player must successfully place a detonator on the reactor and escape through not one, but five slow-moving doors. The trick though is that while the doors stay open as long as the player is beyond their threshold, once he or she crosses it the doors close in a matter of seconds. If the player is caught in between one of the sections however, the doors can be reopened by a switch on the wall.
- Some of the doors in Star Wars Droidworks do this, particularly the huge stone ones in the 5th training mission and Salvage Yard.
- The final level of Syphon Filter has this. You have to make it through a missile silo before the missile blasts off. There's a slowly closing blast door, and the controller has an Unnecessary Combat Roll button. Do the math.
- Parodied twice in Futurama: In the Central Bureaucracy everyone manages to make it through the door, except Bender, who just walks right through the metal. The second one is when fleeing the spaceship Titanic, when Zoidberg stops the door with only a few inches of space, forcing Hermes to limbo underneath.
- Subverted in Wallace & Gromit: The Wrong Trousers. When Wallace under the control of Feathers Mcgrew attempting to steal a diamond trips a laser beam, the chamber's vertically-dropping entrance door starts to close slowly (about 10 seconds after the alarms first go off), but instead of attempting an Indy Hat Roll, he instead immediately turns around and heads for the window - granted, he was walking on the ceiling!
- The world's largest doors, on NASA's Vehicle Assembly Building, take 45 minutes to open or close.
- Generally blast doors weighing many tonnes are not prone to very sprightly movement. For example the doors at Cheyenne Mountain take about 20 seconds to open and close.
- Automated garage doors. Unfortunately, IR detectors take out the drama of trying an Indy Hat Roll. Fortunately, they also prevent your arm from being crushed if you are too slow pulling in your fedora.
- The extremely giant doors on the roof of the new Dallas Cowboys football stadium take SEVENTEEN MINUTES to open and close.
- The Maeslant barrier are a set of doors that can close off the New Waterway (the entry to the Port of Rotterdam) in the Netherlands to prevent flooding in the case of a storm surge. They take over half an hour to close. Not all that surprising considering the barrier is almost as long as the Eiffel Tower, and weigh about 4 times as much.
- And that just for the physical act of getting both sides to meet in the middle. The entire procedure from the first warning of a possible closure to the barrier being shut completely takes close to 9 hours.
- Bank vault doors are sometimes fitted with a delay mechanism that forces anyone opening them to wait for a preset amount between activation and releasing the locks. The doors themselves open rather quickly though.
- Entirely subverted in underground nuclear testing, where specialized sensors would normally be annihilated by the blast wave of the weapon. How do you get data on how properly an atomic weapon goes off, without going with it? Massive blast doors are installed at the end of the shaft, just in front of the sensors, while the weapon itself is positioned hundreds (or thousands) of feet away. The doors themselves don't bother with simple mechanical power, and are closed shut by an explosive reaction slamming them together in the milliseconds between the initial energy front arriving at the sensors, and the thermal surge and fireball immediately following. Of course, to get it to work you need to have the doors start closing before you set off the atomic weapon, so the timing is everything - and from the nuke's perspective, at least, those are some pretty slow doors...
- Entirely justified with water-tight doors used in ships. The main reason for this is because if they slammed shut in seconds, you'd trap personnel who could be later be useful in damage control or evacuation. However, once the doors are closed, the only way to open them is back at dry dock as modern water tight doors have sensors that prevent them from opening if the water is above a certain height. In short, when the doors start to close, GET OUT OF THE ROOM.