[[quoteright:118:[[VideoGame/XWing http://static.tvtropes.org/pmwiki/pub/images/x-wing-power_3407.jpg]]]]
[[caption-width-right:118:[[StandYourGround Cut power to the engines]], [[BeamSpam full power to the lasers]]!]]

According to TimTaylorTechnology, all you need to do to enhance a system is pump more power into it. But where do you get that power?

Diverting Power is what happens when Tim Taylor Technology runs into a limited pool of power. If the extra power to pump into something is not readily available, [[EquivalentExchange that power must be reclaimed from somewhere else]], usually by shutting down or reducing power to one system to power up another.

Played well, this can add extra tension and interest. Buffing up one aspect of something can expose a LogicalWeakness in another aspect. [[AwesomenessByAnalysis An observant hero]] might use this to dodge the extra danger of one foe powering up an aspect of himself by exploiting the aspect he left vulnerable. Or a WaveMotionGun might be enough to end a battle in one shot, but doing so requires that the user power down all other systems and leave himself vulnerable, thus justifying [[HoldingBackThePhlebotinum why he does not use it all the time]].

Note that most of the uses of this involve technology using presumably electrical charge or MinovskyPhysics. However, this trope can also apply to something using [[SteamPunk steam pressure]], FunctionalMagic, or other similar concepts, depending on how they are handled in the context of a particular setting.


* ''Franchise/StarWars'':
** ''Film/ANewHope''. Before the final battle over the Death Star, the Rebel pilots were ordered to "Switch your deflectors on double front" (i.e., switching the deflector shields to increase forward deflectors at the expense of the rear ones). Once the TIE Fighters show up on the scene, the pilots are ordered to stabilize their rear deflectors, now that they are being chased as well as being shot at by their target.
** ''Film/TheEmpireStrikesBack''. Han Solo orders all power to the forward DeflectorShields before charging the ''Millennium Falcon'' straight at an Imperial Star Destroyer, since he knew he would not need to worry about firing coming from behind [[spoiler:as he was planning on parking his ship on the rear side of their command tower and out of their sensors' scope]].
* Used offensively in ''Film/StarTrekGenerations'' when the ''Enterprise'' is locked in a duel with Klingon Bird-of-Prey owned by the Duras sisters. Having been able to bypass the Enterprises' shields, they need a quick solution. Data figures out some TechnoBabble that can force the Bird-of-Prey to go into [[StealthInSpace cloak]]. Since cloaking requires that a ship power down its weapons and shields (see ''Star Trek'' under "Live Action TV" below) this allows the Enterprise to render the Bird-of-Prey defenseless for a brief window that they can use to hit it with photon torpedoes. Being a much smaller ship, it cannot take nearly as much hull punishment as the Enterprise and is destroyed.
* In ''Film/{{Apollo 13}}'', Ken Mattingly and John Aaron are trying to come up with a startup procedure for the command module using only the CM's batteries, which had been partially drained in the disaster before the CM was shut down. Unfortunately, there just is not enough power in the batteries to perform any viable startup. Mattingly gets the idea to get the extra power from the lunar module's power systems, via a linkup normally used to transfer power from the command/service module to the lunar module. It's not very energy-efficient when [[ReverseThePolarity used in the reverse manner]], but it gets them the few extra amps they need to get the CM up and running--and thanks to the earlier power conservation procedures used with the LM, there's power enough to do this.

* Creator/KeithLaumer's short story "The Last Command". After the last battle against the enemy, Literature/{{Bolo}} unit LNE (Lenny) is deactivated and sealed underground. Many years later he's awoken by the detonation of explosive charges and tries to escape his confinement. He activates his forward scanners and shunts power to his I-R microstrobes. He channels all available power to a single ranging pulse in an attempt to figure out where he is. Near the end, when his old commander tries to convince him to not drive into the human city nearby, LNE shunts power to his forward scanner again in an attempt to verify the commander's identity.
* Comes up on occasion in the ''ComicBook/XWingSeries'', which borrows several elements from the ''VideoGame/XWing'' PC games. The X-Wings are capable of diverting power between several subsystems, most commonly the shields, engines and guns.
* This ends up [[spoiler:killing Ax]] in ''Literature/{{Animorphs}}'': his ship is investigating what appears to be a derelict Yeerk ship, and he joins the boarding party while his own ship is diverting power to the scanners. On iguring it's a trap, he tells his ship to send full power to the shields, but it's too late.
* Literature/SherlockHolmes claims this is the reason he rarely eats while on a case: blood sent to the digestive system could be put to better use by his brain.

* This happened on a regular basis during space combat on ''Series/StarTrekTheOriginalSeries''.
** "The Changeling". Scotty diverts warp power to the shields to defend against Nomad's energy bolts.
** "Balance of Terror". The Romulan ship had to turn off its cloaking device in order to fire its plasma weapon. Also, Kirk orders all power diverted to weapons before making the final attack on the Romulan ship.
** "Catspaw". Assistant Chief Engineer [=DeSalle=] orders power diverted to the hull in an attempt to escape their imprisonment.
** "The Tholian Web". Spock orders all but emergency maintenance power to be diverted to the shields to resist the Tholian attacks.
** "The Immunity Syndrome". While inside the giant space amoeba, Spock diverts his shuttle's secondary power to the shields.
** In all of the ''Star Trek'' incarnations activating a [[InvisibilityCloak Cloaking Device]] requires that a ship divert power away from its weapons. In the original series episode ''Balance of Terror'' where the cloaking device was first introduced, it literally used up too much power to run both it and the weapons system at the same time. Later instances seem to have gotten around this particular issue, but new issues come up that still keep the trope enforced. The writers described it as being akin to an arms race between cloaking technology and sensor technology, and any advantage one gains over the other is only temporary until the other side figures out a work-around. This then keeps cloaked ships as the equivalent of "[[StealthInSpace submarines in space]]", having to reduce all the emissions that might give them away when they go into cloak.
* Parodied in [[Recap/CommunityS2E04BasicRocketScience "Basic Rocket Science,"]] an episode of ''Series/{{Community}}'' that [[AffectionateParody spo]][[{{Homage}} ofed]] ''Film/TheRightStuff'' and ''Film/{{Apollo 13}}''. The gang, sans Abed, are trapped on a space exploration simulator and have no clue as to where they are. [[MissionControl Abed and a few others at Greendale are tasked with finding the gang and bringing them back to the school.]] About halfway through the episode Chang comes running to Abed with a plan.
-->'''Chang:''' I've worked out a way to reroute the RV's power from the auxiliary battery!
-->'''Abed:''' Reroute to what?
-->'''Chang wordlessly backs out of the room.'''
* Standard spacecraft function in the ''Franchise/StargateVerse''. Typically they're switching between DeflectorShields and engines.
** In ''Series/StargateAtlantis'', there was a more specific case, when Atlantis was hooked up to a [[InvisibilityCloak cloaking field]], making it invisible, but using the same power source as the shields, so the city could only be either invisible or shielded at a given time.
*** This was not a case of diverting power. The shield was reconfigured as a cloak, so was no longer available as a shield. Power was not the issue. In ''Grace Under Pressure'' the process is reversed, with Puddle Jumpers' cloaks reconfigured as shields.
* ''Series/BlakesSeven''.
** In "Games", Avon has all power except that which is necessary for life support diverted through the weapon system.
** In "Terminal", the Liberator's hull is breaking down after being infected by some kind of enzyme. Villa orders Zen to shut down the auto-repair systems as they're fighting a losing battle and draining the power banks, and instead divert all power to maintain the MasterComputer so it can analyze the infection and find a solution. [[spoiler:Unlike other examples of this trope, it doesn't work and Liberator is destroyed.]]
** Averted in "Volcano". With the Liberator's power banks drained and Servalan's battlefleet bearing down, Avon calls for the emergency circuits to be activated. They don't work [[spoiler:and only a convenient EarthShatteringKaboom saves their lives.]]

* ''TabletopGame/StarFleetBattles''. Since the game is based on ''Series/StarTrekTheOriginalSeries'', one standard technique during combat is to move around your ship's available energy to where it's needed.
* In ''TabletopGame/{{Traveller}}'', Jump drives use so much power that many older ships have to divert power from nearly everything (leading to the tradition of "jump dimming").
* The multipower framework in the ''TabletopGame/HeroSystem'' works like this. For a lower point cost than buying all the powers in it piecemeal would entail, the character instead gets a total point pool that can be split up between them -- a classic example would be a character who can have flight, a force field, and an energy blast, but can't have them all running at full power at the same time.
* In ''TabletopGame/DungeonsAndDragons'' 3.5, the incarnum subsystem (presented in ''Magic of Incarnum'') expands on the body slots used to equip magic items, most notably by allowing characters to enchant these slots with pieces of [[BattleAura spectral equipment]] known as soulmelds. Incarnum-wielding characters gain a limited pool of "essentia" which can be invested in soulmelds (and certain other abilities) to increase their power, and which can be reallocated between them from round to round. A number of classes have bonuses and {{Super Mode}}s which either increase the maximum essentia capacity of their soulmelds, or cause soulmelds to function at maximum power without any investment.

* As a general rule, most Space SimulationGames will involve this as a ResourcesManagementGameplay mechanic.
* ''VideoGame/XWing'' was a series that helped popularized it.
* ''VideoGame/TachyonTheFringe'' allows you to divert power between your forward and aft shields, and between your engines and recharging shields, guns, and afterburners.
* A minor example in the ''VideoGame/{{X}}-Universe'' series, which allows you to switch sets of guns on and off. This can conserve power, but it's more commonly used to swap between weapons for specific targets (such as switching to a low-damage, high-ROF gun to {{Cherry Tap|ping}} enemy fighters in the hopes the pilot will bail out).
* This is a core mechanic in ''VideoGame/FTLFasterThanLight''. You'll never have enough power to operate every system in your ship at full capacity, even after upgrading the reactor several times. Therefor, [[ResourcesManagementGameplay it's imperative to adjust power distribution wisely]] according to the situation at hand.
* Games based on ''Series/StarTrekTheOriginalSeries'' often allowed the player to do this. For example, in ''Super Stellar Trek'' and ''Apple Trek'' the player could transfer energy from reserve power to the shields and back again. Energy in the shields couldn't be used to fire phasers or move the ship.
* In ''VideoGame/MassEffect3'''s multiplayer mode, certain classes of [[MechanicalLifeforms Geth]] characters can enter "[[OverclockingAttack Hunter Mode]]", lifting the {{Power Limiter}}s on their weapons to fire them with greater force, diverting power to their synthetic muscles to handle the recoil that would break an organic's arm. However, this power is drawn from their DeflectorShields, reducing them to half strength[[note]] This is half of the shield's base strength of 1000 points. Any bonuses to shield strength, whether through passive skills, equipment, or consumable items, apply their full value, so a Geth Engineer with 1000 base shields and cumulative bonuses of +100% to shields that entered Hunter mode would have 1500 shield points, not 1000.[[/note]] while this mode is engaged and turning the Geth into a GlassCannon.
* ''Franchise/{{Halo}}'':
** Most Covenant vehicles after the [[VideoGame/HaloCombatEvolved first game]] allow the player to "[[{{Overdrive}} boost]]" by diverting power from the weapons to the engines, granting temporary extra speed but unable to shoot while doing so.[[note]]Though there is an exception when Covenant vehicles have a secondary turret operated by a separate gunner. Presumably the secondary turret operates on its own isolated circuit.[[/note]]
** There are several times in the games where the Cortana has to use the Chief's suit's reactor to overload some sort of power system; doing so usually temporarily depletes the Chief's energy shields.
** In ''VideoGame/{{Halo 4}}'' there is a specific example. At the end of the third mission, "Forerunner", the Master Chief and Cortana must escape a CollapsingLair on a Covenant Ghost. Given that they need even more speed than the boost would usually give them, Cortana diverts power from the Master Chief's DeflectorShields to the Ghost's engines. This does leave him vulnerable, but any Covenant he encounters along the way are too busy running for their lives to try shooting at him.
* To progress through the Bugbear Mothership in ''VideoGame/KingdomOfLoathing'', the player has to deal with various things diverting power from the elevators. [=KoL=] being [=KoL=], this is eventually lampshaded.
-->''A computerized voice says, "De-Evolution Detected in Galley. Rerouting Power From Elevator To Food Replicators."''
* In ''VideoGame/AlienIsolation'', power switch boxes can be found all over Sevastopol, and because the systems are usually operating at only nominal capacity at best, [[PlayerCharacter Amanda]] often has to switch various systems on an off to gain access, evade hostile security, make distractions, or any number of other things.
* ''VideoGame/StarTrekOnline'' has power distribution as a major mechanic in space combat. Ships have 200 points of power (160 for Romulan ships, whose power plants grant several special abilities) to be distributed between weapons, shields, engines, and auxiliary systems. Most ships grant bonus power to one or more systems, and player character skills or ship equipment can also increase the amount of power available.

* This is effectively how Maxima's powers work in ''Webcomic/GrrlPower''. She has superhuman strength, speed, and invulnerability as well as flight and energy blasts. Typically she keeps a balance between them, but when the situation calls for it she can switch power from one ability to another; for example, she could lower her SuperStrength to improve her [[NighInvulnerable invulnerability]] in anticipation of a powerful attack.

* ''WebVideo/StarWarsDownunder''. Jedi Knight Merve Bushwacker's spaceship can divert all power to the [[INeedAFreakingDrink beer fridge in case of emergency]].

* ''WesternAnimation/StarTrekTheAnimatedSeries'' episode "The Lorelei Signal". Spock orders ship's energy to be diverted into the deflector shields in an attempt to block the title sonic MindControl attack.
* Discussed in the ''WesternAnimation/DextersLaboratory'' episode "Overlabbing". Dexter explains that he shielded his lab in response to one of Mandark's schemes, and Mandark immediately investigates.
-->'''Mandark:''' You must take me for a fool! Rerouting power from the deflector array?
-->'''Dexter:''' I guess that is a little cliché.