For one reason or another, you need to have an important item (can be a MacGuffin or any other Plot Device) or an important person be moved to another place. But Vulnerable Convoy is a thing, especially if there are bad guys who want to steal the item or take the person away (or kill them).
So what to do? Simply reinforcing the convoy may not always work (and may give it more attention). Enter this trope.
This usually takes form of having more than 1 carrier, each going to a different direction, and only one of them carries the real item/person; the rest either carry an empty container or (for more elaborate cases) the fake version of the item/doubles of said person. Other times, the fact that the convoy you're seeing is a decoy all along may be played as The Reveal (and/or even an Internal Reveal for the carrier) as the real item/person is safely carried by another person/transportation. There might even be multiple layers to this "decoy". They're all meant to confuse the would-be stealers into potentially raiding the wrong convoy.
Compare Decoy Getaway for cases of "escaping with layers of deception", Needle in a Stack of Needles for hiding something among its lookalikes, and Shell Game, a more general case of "only one of them is real". Not to be confused with Escort Distraction, where character A escorts B somewhere else to distract them from C and whatever it is he's doing. See Gideon Ploy when you have to fake decoys.
- Done in episode 34 of Beast Wars II, when the Maximals prepare a plan to shoot down a massive artificial planet that Predacon leader Galvatron has summoned to the planet Gaea. The majority of the Maximals make a big show of transporting the massive Niagra Cannon, drawing the attention of some of the Predacons. The more savvy Hellscream suspects it's a decoy, and sure enough discovers the Maximal Scuba transporting another cannon through an underground river. As it turns out, both cannons are decoys: when the Maximals have pinned down the Predacons, the real cannon is carried to the target zone by the combiner Magnaboss.
- In Ghost in the Shell: Stand Alone Complex, Kazundo Ghoda tasks Section 9 with escorting a case of plutonium through a refugee zone, acting as security in case the refugees try to get their hands on it. At the end of the episode, Ghoda reveals that there was no plutonium inside the case, and the Japanese Self-Defense Army relocated the actual plutonium without incident.
- Hunter × Hunter: In the 13th Hunter Chairman Election arc, Killua is escorting Alluka. To throw off pursuers, he hires 7 additional airships to carry them to their next destination. The decoys fail mostly due to the World of Badass nature of the setting.
- When Phantom Thief Jeanne goes after the british ambassador's pendant he devises a plan to send additional two fake limousines so Jeanne will have no idea, which one is he actually in.
- Captain America: After Steve's death, SHIELD transports his iconic shield by deploying four identical vans in four different directions, one of which allegedly contains the weapon. Bucky Barnes is savvy enough to know that it's just for show — SHIELD wouldn't trust just anyone to transport it. His suspicions are proven correct when Black Widow emerges some time later, carrying the real shield.
- Clone Wars Adventures: In "The Chain of Command," a recently knighted Jedi is sent on a courier mission that is really meant to distract the Separatists while Ki-Adi-Mundi and Aayla Secura carry out another mission. Only, it turns out that they themselves are being manipulated into carrying out a pointless task to distract them from interfering in one of Palpatine's schemes.
- In Jon Sable, Freelance #7, police are moving a star witness in a mob trial to a new location when the car is hit by an an assassin with a rocket launcher. The car turns out to have been a decoy, but the attack spooks the witness so much that she runs.
- Lucky Luke: In "The Stagecoach", Luke is hired with much fanfare to protect a Wells Fargo stagecoach carrying a large amount of gold. At the end of the book, it turns out they risked life and limb to protect a load of rocks, while the actual gold went in a second stagecoach.
- In the Final Fantasy VII fanfiction Deliveries, Cloud is hired to deliver precious tea leaves to a televised tea ceremony, which have to be put into the teapot within an hour of being picked. Since the tea ceremony is part of a PR stunt between Wutai and Shinra, Cloud's friend Yuffie tries to stop it by sabotaging his motorcycle, tipping off Reno and Rude that the tea is poisoned, and finally breaking their helicopter. Only after the mission fails do they discover that Cloud was a decoy; the ceremony had been filmed some time before, and the 'live broadcast' was prerecorded.
- In 3:10 to Yuma (2007), the lawmen need to transport outlaw Ben Wade to the prison train without his gang freeing him. They make a big show of putting Ben Wade on a stagecoach, then secretly swap him with one of their own men—leading Wade's gang off one way, while they actually take Wade on horseback the other way.
- In Abraham Lincoln: Vampire Hunter, Abe and a few crewmen are securing a train that carries silverclad weapons to be used against the Confederacy vampires in the Civil War. Predictably, the vampires - including the Big Bad, Adam - tries ambushing the train... Only to find out that the train contains no silver, except for Abe's pocket watch (which he uses to kill Adam). The real silver stocks were actually being delivered on foot by the Underground Railroad, not a literal railroad, and that convoy goes safely, allowing the Union side to decisively win the war with silver bullets.
- The Mafia uses this tactic in Analyze This to confuse law enforcement agents who know there's a mob meeting about to disperse at a warehouse so that they don't know which of the several limousines driving around has the mob head they're trying to nab — their on-site agents are using a helicopter up high so they can't see into the windows to tell who's inside each one.
- The Dark Knight Rises: Bane holds the city of Gotham hostage with a fusion-reactor-turned-bomb, leveraging it to prevent anyone from fleeing or assaulting the city. The bomb is driven around the city in a truck, and several more decoy trucks patrol Gotham to confuse citizens as to which one really holds the bomb.
- In Eastern Condors, two planes are sent on the mission. One contains a squad of Boxed Crooks who are supposed to parachute and be a diversion, causing the Vietnamese army to run around chasing them. The second plane contains an elite special ops unit who will parachute in and destroy the bunker. However, the second plane is shot down, leaving the Ragtag Bunch of Misfits to attempt to achieve the original mission.
- The Italian Job (2003): Steve uses three identical convoys of armored trucks with motorcycle escorts to hide the gold while it's moved to a more secure location. Lyle is able to figure out which one has the gold by seeing which one is weighed down since $27 million in gold is heavy.
- Mad Max 2: The Road Warrior: At the climax, part of the Northern Tribe goes with Max, driving a fortified tanker truck away from the refinery, which is set to explode. This succeeds in drawing Lord Humungus and his gang away from the rest of the tribe, who are carrying dozens of barrels of fuel in their vehicles for their journey to Queensland; the truck that Max is driving is full of sand.
- The Mongolian Connection: Ganzorig and the Mongolian cops, assuming that the Mafiya will attack them, organize a decoy convoy to the courthouse, while actually transporting Serik (their informant) in an ordinary cab. Sure enough, the decoy convoy is assaulted, and the cop pretending to be Serik is killed.
- Ocean's Twelve: In order to win the challenge imposed onto them by Gentleman Thief Toulour "The Night Fox", Ocean's Eleven must steal the Faberge Imperial Coronation Egg from a museum where it is being exhibited. Once almost the whole group has been captured and things look bleak, it is explained that the Faberge Egg arrived to the museum on one of these (the "official" convoy being a number of armored trucks and police escort and the real convoy being a man carrying it on a backpack in a bullet train alongside a few plainclothes bodyguards)... and the Eleven had stolen it while it was en route, meaning they had already won the challenge shortly after Toulour had made it, and the whole film up to that specific point had been them going through the motions in order to distract him from this fact.
- Patriot Games. When a terrorist is to be transferred between prisons by van, a number of decoy vans are sent out at the same time in various directions to confuse anyone who wants to free the prisoner. The trick fails and the other terrorists capture the real van because The Mole tipped them off.
- Fritz Lang's film Spies features a Japanese diplomat giving three people identical envelopes to deliver, one of which supposedly contains a treaty. In reality, the diplomat has the actual treaty; all three envelopes are decoys.
- In S.W.A.T., after an LAPD helicopter attempting to take Alex Montel to a federal prison is shot down, they make a second attempt with a motorcade, which is attacked by a group of heavily armed Gangbangers. One makes it all the way to one of the SUVs before discovering that there's only a dummy inside; Hondo and Street's SWAT Team snuck the real Montel out in unmarked cars with the motorcade as a diversion. Boxer comments that Hondo once used the same trick to move the President in a Noodle Incident.
- Van Helsing: While transporting Frankenstein's Monster to Rome, Van Helsing's carriage is attacked by Dracula's brides; Van Helsing escapes but the carriage falls into a ravine. One of the brides dives into the ravine and pries the door of the carriage, only to find a bomb lined with silver stakes that promptly blows up and impales her. Riding away from the ravine, Van Helsing spots the carriage that's actually transporting the monster, being driven by Anna.
- In Harry Potter and the Deathly Hallows, six people disguise themselves as Harry using the Polyjuice potion (making them exact duplicates of Harry) and fly to different safehouses along with a member of the Order of the Phoenix (using brooms, flying horses called thestrals and a flying motorbike for Harry himself). Each safehouse contained a portkey to transport themselves to the burrow.
- In Raising Steam, when a civil war erupts in Dwarfdom and the safety of the legitimate Dwarf monarch has to be assured, several royal decoys are sent out to confuse the issue and to draw the rebel forces into ambushes; while the rebels are wasting time and energy on the fakes, the actual Low Monarch is safely aboard a train and is halfway there before the usurping faction catches on.
- In the first part of Leonid Solovyov Tale of Hodja Nasreddin, when the hero is captured at the end, they put him in a sack and take him to be executed. Since Nasreddin's friends are likely to try and save him, four sacks full of rags are brought out first as decoys. Only one makes it to the place of the execution.
- The F.B.I.: "The Giant Killer". Convinced that a fanatic is going to launch an attack a convoy transporting a missile, the FBI persuades the Air Force to send out a decoy convoy first, and send out the real convoy two hours later on an alternate route. The fanatic does attack the decoy, but on realizing it is a fake, sets out to locate the real convoy.
- In season 4 of Justified, the Marshals are trying to escort Drew Thompson out of Harlan County and into federal custody. However, they are deeply outnumbered by henchman for the Tonin Crime Family who want Thompson dead so that he can't turn State's Evidence against mob boss Theo Tonin. Every road out of town is being patrolled by heavily armed men who are not afraid to shoot at the law. The Marshals break into two teams, one a decoy convoy and the other an escort team for Thompson. The decoy convoy, using the flashy, trademark Fed SUVS, ends up in a tense, psychological battle of IEDs and Army snipers while the other team sneakily and successfully escorts Thompson onto a train hauling coal out of town.
- Used once in a two-part NCIS/NCIS: New Orleans crossover when a Russian diplomat dies and Gibbs wants the body covertly transported to New Orleans. Ducky and Jimmy are (of course) the obvious choice, so when their autopsy van is ambushed, the body isn't on board. Cue Ellie Bishop pulling into the NO office with the body.
- The New Avengers succeed in smuggling a Soviet scientist into the United Kingdom. However, the man's heart is weakened from being malnourished and overworked. The heroes transport the scientist to hospital in an ambulance, which is followed by Soviet agents seeking to repatriate the defector. Two more identical ambulances appear, and the three emergency vehicles then shuffle themselves like a shell game, including through a tunnel. At an intersection, one ambulance goes left, one goes right, and one goes straight. The Soviet agents come to dead stop, unsure which ambulance to pursue.
- Power Rangers Lightspeed Rescue: While the rest of the team is guarding a fuel cell, Dana is tasked with giving her father's friend a ride. It turns out the real fuel cell was with Dana and the friend while the others were guarding a fake.
- Fallout: New Vegas: Mr. House has his high tech platinum chip, a computer storage medium disguised as a poker chip, delivered to him by hiring seven couriers, six of whom are carrying junk like a chess piece and a pair of fuzzy dice. The seventh and final courier is the Player Character and is carrying the platnium chip. Unfortunately, the decoy gambit fails when one of House's top lieutenants discovers who's carrying the real chip and ambushes them to steal the chip for himself, setting up the game's plot.
- Grand Theft Auto: San Andreas: One mission has CJ driving an SUV with tinted windows so an allied mob boss can escape the country. The added difficulty is that if the vehicle becomes too damaged, the assassins will be able to see the boss isn't inside and go after the other cars before he can reach safety.
- Mobile Suit Gundam: Encounters in Space combines this with Schrödinger's Butterfly. In the final mission of the Thoroughbred's story, the player is tasked with escorting Zeon's newly empowered prime minister to the peace talks so Zeon can surrender to The Earth Federation to end the One Year War. If the mission fails, it's revealed that the ship you were escorting was a decoy and the real prime minister successfully made it to the peace talks on a different ship.
- In Act 3 of Metal Gear Solid 4: Guns of the Patriots, you discover that Big Mama is in possession of Big Boss's body and keeping him hidden from The Patrios. However, Liquid Ocelot's forces are closing in, and Big Mama doesn't want Ocelot to have the body either, so she makes a plan to rush the body out of the city by putting it in one of several black vans and speeding them off in all directions under escorts. The van that you and Big Mama escort gets discovered, but Big Mama reveals that that van was also a decoy: the one containing the actual body was being snuck out on a boat through the river while the guarded ones drew the enemies attention. Unfortunately, that one got discovered as well, and Big Boss's genetic information is retrieved and his body destroyed.
- That is, until an unharmed Big Boss shows up at the end of the game. It turns out the van on the boat was also a decoy, complete with a fake Big Boss body. The real Big Boss was successfully snuck out through some other unmentioned method, or possibly wasn't even in the city to begin with.
- Girl Genius: When Agatha needs to get to Paris, while being chased by both Gil and Tweedle, she sends out at least two coaches with imposters on board, while she boards one of the Corbettites' trains.
- Ed, Edd n Eddy: In "Mission: Ed-Possible", Edd is tasked with delivering Ed and Eddy's terrible report cards to their parents, leading to a tense chase to the cul-de-sac so they can take the cards and doctor them. Once they get their hands on Edd's satchel however, they find it's empty; it turns out that Edd entrusted Rolf to deliver the report cards while he himself acted as a decoy.
- An episode of G.I. Joe involved the Joes being asked to help transport a virus to a safe spot to destroy it, knowing very well that COBRA will try to capture it. After braving a whole lot of traps, ambushes and other risks, the team assigned to the convoy finds out that they were assigned to the decoy convoy and the virus was transported and disposed in a more covert fashion. They were not okay with the fact that they were not provided this information.
- In Regular Show episode, "Trailer Trashed", a safety inspector comes to the park to do an inspection and, upon seeing Mitch (aka Muscle Man)'s trailer home, tries to confiscate it. When Mitch refuses, the Park Crew agree to help him try to get it somewhere the inspector can't find it and load it into Muscle Bro's trailer truck. A chase ensues between the crew and the Inspector and his flunkies until it comes down to Mitch and the inspector who reveals he's a contestant who lost the trailer in a hot dog eating contest against Mitch years ago. However Mitch bails out the truck and the inspector finds that trailer wasn't even in it before going over a cliff. Mitch reveals to the crew he had moved the trailer elsewhere and had Fives guarding it while luring the inspector into chasing a decoy. Though... didn't tell his brother that he was going to destroy his truck however. Whoops.
- Transformers: Prime has a variation. When the autobots assist Fowler in transporting a prototype nuclear generator they are attacked by M.E.C.H, during the chase they go into a train tunnel and they are pursued further once they come out the other side, later on M.E.C.H leader Silas figures out they put the generator on a passing train when in the tunnel.
- In the Young Justice episode Schooled, the Justice League, having recently defeated the powerful android Amazo, has its different parts separated and sent to different facilities in separate trucks, with a number of the trucks being decoys, all guarded by different Team members. Unfortunately for them, Amazo's creator, Doctor Ivo, is capable and Genre Savvy enough to just have his minions attack ALL the trucks.
- The Cullinan Diamond, was sent to Britain in a safe, on a guarded boat... or rather, a decoy was. The real stone was simply mailed in a plain package.
- The President of the United States when traveling by helicopter. Three or four identical helicopters are used so no outsider knows which one he is on. They also sometimes use several identical presidential limousines in motorcades.
- When Adolf Hitler moved around Europe in his private train Amerika, it was standard procedure to send decoy trains ahead and behind of the main one, to confuse people planning to sabotage the rails and/or ambush the train.