A military trope where a unit is ordered to go out somewhere, with the Captain only being informed of his or her orders after they have left. This is to ensure security. Spies in port will have no chance of picking up loose talk from the crew and spies actually in the crew will have much difficulty informing their superiors once the ship has left the harbour. The disadvantage is that the Captain is also likely to have much difficulty in asking for clarification of his orders.

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!!Examples:

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[[folder:Film]]
* The film ''{{Push}}'' centers around Sealed Orders to get around the mind reading capabilities of a psychic. The one who came up with the plan also [[MemoryGambit has his memory of coming up with it wiped]] to further ensure its success.
* In ''DoctorStrangelove'' and ''FailSafe'' the bomber crews only unseal their targeting orders after the attack command is given. In the latter, they consist of one word- "MOSCOW".
* ''Captain Horatio Hornblower''. At the beginning, the narrator says that Hornblower's ship sailed "under the most secret of sealed orders".
* Film/TwoThousandOneASpaceOdyssey: HAL's sealed orders, and the anxiety over having to lie, are what [[spoiler: causes him to go psychotic and murder the crew]].
* ''WesternAnimation/{{WALL-E}}'': [=AUTO=] has sealed orders to [[spoiler:not return to Earth]], one of many {{Shout Out}}s to ''2001''.
* ''Film/TheHuntForRedOctober'' (much like the [[Literature/TheHuntForRedOctober novel]] below) has [[TheCaptain Captain Ramius]] and [[ThePoliticalOfficer Political Officer Putin]] pulling the sealed orders out of a [[TwoKeyedLock dual-keyed wall safe]], and reading them in private. A major plot point as [[spoiler:Ramius crushes Putin's windpipe ("There's been a terrible accident"), and then burns the orders, allowing him to maintain the ruse that they were ordered to go to America.]]
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[[folder:Literature]]
* In ''Literature/TheHuntForRedOctober'', [[TheCaptain Captain Ramius]] and [[ThePoliticalOfficer Political Officer Putin]] get their sealed orders from a [[TwoKeyedLock dual-keyed safe]] after they sail. [[spoiler:Ramius then [[NeckSnap breaks Putin's neck]], spills tea on the deck near the dead man's feet to make it look like [[DeathByFallingOver he slipped]], and substitutes the actual orders with orders to sail to Cuba via the American coastline.]]
* The Franchise/StarTrek novel ''Mission to Horatius''. ''Enterprise'''s mission (to investigate a distress signal) is in this form.
* The novelization of the ''Series/StarTrekTheNextGeneration'' episode "Encounter at Farpoint" had Captain Picard being given SealedOrders about what he was to do when ''Enterprise'' reached Farpoint Station.
* It doesn't involve a ship setting sail, but in the ''Literature/CodexAlera'' book ''Princeps' Fury'', Tavi foils the Vord's ability to read minds by setting up whole ''strings'' of sealed orders given to several people with strict instructions to open each one only when told to by the preceding order.
* When [[Literature/TheBible King David]] slept with the wife of Uriah, David [[TheUriahGambit eventually murdered him]] through this method: he sent sealed orders through Uriah to the general, which instructed the army to pull back and let Uriah die in the heat of the battle.
* In ''[[Literature/SixteenThirtyTwo 1633]]'', Cardinal Richelieu has become fond of using sealed orders after reading about them in an up-time book, preventing drunken sailors on shore leave from accidentally spilling secrets.
* ''Sealed Orders'' is an alternate title for ''Literature/{{Retief}} of the Red-Tape Mountain'', where Retief has sealed orders for how to handle a diplomatic dispute on the planet Adobe. Since he knows his superior doesn't know a hawk from a Groaci nose flute, he plays the whole affair by ear and [[spoiler:after succeeding admirably, dumps the still-unopened orders into an incinerator]].
* This is used numerous times int he ''Literature/HonorHarrington'' series, by all sides of the various conflicts. The first and probably most notable one involved a double deception involving false orders and sealed orders to throw of enemy spies allowing Admiral White Haven to ambush a Havenite attack force in Yeltsin.

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[[folder:Live Action TV]]
* Parodied in ''Series/DadsArmy'', where [[TheCaptain Captain Mainwaring]] is given not only sealed orders but also "Sealed Instructions for Opening Sealed Orders"; when their seal is broken, they read "Break the seal on the sealed orders and then destroy these instructions".
* ''Series/StarTrekTheOriginalSeries'', "The Enterprise Incident".
* ''Series/VoyageToTheBottomOfTheSea'' episode "Sealed Orders". The orders are to dispose of a NeutronBomb.
* The main characters in ''Series/BattlestarGalacticaBloodAndChrome'' only received their top-secret orders after they had already left for a routine supply run, and RadioSilence as in effect so they couldn't double check if the orders were genuine.
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[[folder:Tabletop Games]]
* In [[TabletopGame/{{Chess}} chess]], a variant on sealed orders occurs whenever a chess match is suspended for the day (i.e., dinner time) and will be continued at a later time. The position of each piece is recorded, and the player whose turn it is to move writes down what his move will be and then seals it up and hands it to the judge. When the match resumes, the order is revealed and the game continues from there. This is so that neither player will be allowed potentially hours upon hours to think about the position and come up with a potentially better move because he was able to memorize the board.
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[[folder:Video Games]]
* ''TheKobayashiAlternative''. Captain Kirk receives SealedOrders to locate Lieutenant Sulu's missing ship and neutralize whatever caused it to disappear.
* In ''VideoGame/HalfLife1: Opposing Force'', the incoming Marines are given their alternate orders just before arriving at Black Mesa. Shepherd's squad, of course, gets shot down before they receive their new orders.
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[[folder:Real Life]]
* TheKnightsTemplar went down so fast partly because Philip IV of France's orders to arrest the Templars were issued sealed, so nobody (not even the omnipresent Templars) knew what's inside them until they were all opened simultaneously on Friday, 13 October 1307.
* The captains of the [[BritsWithBattleships Royal Navy's]] four ''Vanguard'' class [[UltimateDefenceOfTheRealm ballistic missile submarines]] are each given a sealed handwritten letter by the Prime Minister when he or she enters office before they leave port detailing what they should do in the event of a nuclear attack on the UK which neutralizes the normal chain of command. These letters are destroyed unopened when the PM steps down.
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