What prevents ships firing phasers and photon torpedoes through a cloak? I have yet to see a episode where this is brought up. It may have been mentioned in The Undiscovered Country, as I know there is a kingon ship that does it, but I have not seen that movie in years. Is it addressed there or somewhere in one of the series'?

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    I believe it damages the cloak, because of how it works. It also is a dead give-away as to where you are. (And since you also can't have shields with the cloak up, giving away your position is a very bad idea)
    – DampeS8N
    Aug 30, 2011 at 19:23
  • Could also be because of limited energy supply, but that's more of a writing excuse.
    – apoorv020
    Aug 30, 2011 at 20:34
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    In Star Trek: Nemesis Shinzen's warbird was capable of firing while in cloak.
    – user931
    Sep 3, 2014 at 4:24

10 Answers 10


A cloak requires the dampening or absorbing of all internal energy emmissions while simultaneously rebroadcasting all background and directed energy emmisions "through" the ship; not a simple task.

Preparing to fire weapons, even torpedos, requires taking multiple actions that would be extremely diffcult to mask or play into the backgound sound. From charging weapon capacitors to acquiring an active target lock it is very likely that the target ship would pick up on even small clues (sudden unexplained miscellaneous energy spikes, active sensor emmissions with no apparent point of origin etc) and take appropriate precautionary measures such as raising their shields.

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    Good answer. While this would certainly apply in battle, where the target is already running at heightened awareness, one might expect that a ship could potentially fire-while-cloaked on a ship who was running under normal conditions, that is, not expecting an attack, and therefore not actively watching for the minutest EM changes.
    – eidylon
    Aug 30, 2011 at 19:31
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    According to Memory Alpha, typical cloaks (non-experimental) require so much power that the weapons simply cannot be fired while the cloak is active. It's not a matter of detectable EM fluctuations when you fire, it's a matter of having to turn the cloak completely off in order to fire at all.
    – Matt
    Jan 28, 2014 at 20:12
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    @Matt - I've rolled back your edit as it added substantial material that may not be in accordance with the original answer's intentions. It would have been better as a comment or a separate answer.
    – user8719
    Jan 28, 2014 at 20:27
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    Cool! I'll add a separate answer.
    – Matt
    Jan 28, 2014 at 21:00
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    It's also entirely possible that the cloaking field, and its dispersal/redirection of energy, would interfere energy-based weapons even if you did fire them. This could make them less powerful/effective, or even damage the cloaked ship, depending on how the energy is redirected. You may end up shooting a phaser straight back into your own tailpipe.
    – Nerrolken
    Dec 6, 2014 at 1:04

Cloaking is usually done via the ship's deflector grid; the deflector shield being an energy field that is being used to envelop the entire ship. They used them to do something that has been experimented with IRL; basically relay signals / light / etc. from one side to the other, around the cloaked ship. A major limit, however, is this is not what the shield was meant for, and, when operating in this manner, it was not operating as a shield. Also, the power drain was such that weapons, and even Transporters could not usually be used when cloaked. Memory Alpha 'Cloaking Device' page

There were several iterations in the development and refinement of them, over the various incarnations of the shows... And there have been ones that could fire when cloaked.

Another advanced cloak was encountered in 2379. The Reman warbird Scimitar employed a new type of "perfect" cloaking device that did not give off any tachyon emissions or residual antiprotons, making the Scimitar completely undetectable while cloaked. It allowed the ship to fire weapons and use shields while cloaked, as well as allow the ship to drop the cloak protecting certain quadrants of the ship without de-cloaking the entire ship at once. The effectiveness of this technology was demonstrated when the Scimitar engaged the USS Enterprise-E, the IRW Valdore, and another warbird in the Bassen Rift, and was able to destroy one of the warbirds and cripple the other without suffering any significant damage. Only through repeated blind targeting, barrages of phasers and torpedoes, and the use of telepathic triangulation by Commander Deanna Troi was the Enterprise-E able to overcome the Scimitar's cloak. (Star Trek Nemesis)

Also, not even going into the movies, if you recall the final episode of TNG, 'All Good Things', you saw a Klingon ship fire while cloaked -- apparently they had resolved that issue, although it being at least a partially alternate time-line, it's canon status is questionable.

  • If I remember correctly the Kligons had a BoP in Enterprise that could also fire while cloaked, but its been awhile.
    – Xantec
    Aug 30, 2011 at 23:40
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    If you remember in Undiscovered Country the Klingon's had a war BoP that was able to fire when clocked, but had no shields when clocked. This was how the assassins where able to sneak upto the Enterprise and Klingon flag ship and frame Kirk/Enterprise for the attack Bean to the Klingon Flag and kill the Chancellor. But as said by Keith it was not perfect, and got a torpedo shoved up there tail pipe, so all and all it was not that they can't it was that it was not a smart more to be someplace that you may get shot at and not have shields. IMHO
    – Vaughn
    Sep 1, 2011 at 3:46
  • @Vaughn Ya know I think this may be the best explanation. It's not that you can't do it while cloaked, its the retaliatory shot that will come back at you after they detect your position and having no shields that prevents it. Aug 6, 2013 at 18:41
  • -1 for "cannoninity". thefreedictionary.com/canonicity Jan 28, 2014 at 21:22

Some can.

In Star Trek VI: The Undiscovered Country, the Klingons built a special Bird of Prey that can fire its weapons while cloaked.

In the Series That Shall Not be Named, the ISS Enterprise from the Mirror Universe is able to fire while cloaked ("In a Mirror Darkly")

As for what you're referring to, typical cloaking devices simply require too much power to allow many other high-power systems to operate concurrently. It's not a matter of weapons making the cloak less effective; it means the weapon system simply cannot fire while the cloaking device is drawing power.

According to Memory Alpha:

Due to the enormous amount of power required to generate a cloaking field, there is by and large not enough power available to also power the weapons and shields...However, there have been several times when advances in cloaking technology have rendered these tactical inefficiencies untrue.


An 'out-of-universe' answer: This is due to the Law of Conservation of Ninjutsu:

In any martial arts fight, there is only a finite amount of ninjutsu available to each side in a given encounter.

You need an awful lot of Ninjutsu to both hide yourself from the enemy and to land attacks on him at the same time. And the premise of most shows is that the protagonists have some Ninjutsu, but just enough to get themselves out of a pinch at the last moment.

Note: This is not the standard mode of application of the law, as you will see when you follow the link. There might be a slightly better-fitting trope...


My understanding has always been one of limited energy supply, at least in the TOS era. As both weapons/shields and cloak required enormous amounts of energy to use, their power systems could not maintain both at the same time as they maintain life support, which is another huge energy requirement.

There was a novel about another experimental Klingon ship. I can't recall what the title was as I read it some 15 or 20 years ago. They took a D7 battlecruiser and ripped out all the life support systems, replacing it with additional power generators. By eliminating the need to support a crew, they were able to generate enough power to supply power to cloak, weapons and shields simultaneously. The ship was linked via remote control to a Bird of Prey. The end result was a battlecruiser that could fire while cloaked, which was controlled by the Bird of Prey crew, which remained safely cloaked and hidden a short distance away while the battle went on, without needing to reveal themselves. So, at least in this instance, it was explained as a power issue.


In Star Trek VI, the main baddie captains a Klingon Bird of Prey that CAN fire while cloaked. It only ever fires torpedoes, either because:

  • Disruptors use more energy, which is needed for cloaking,
  • A torpedo, once fired, doesn't point back to its source like a beam or pulse weapon would, or
  • Torpedos simply do more damage.

Anyway, when a torpedo is fired, it illuminates the skin of that Bird of Prey momnentarily; the energy of the shining ball of destruction is simply too much to overcome.

The reason most others wouldn't be able to fire is mostly because to fire requires bringing targeting systems to bear and otherwise using a lot of energy, which doesn't mix well with trying not to show up visibly or on any sensors. However, apparently transporters DO work while cloaked; this is demonstrated in Star Trek III and in ST: Generations, as well as several episodes of TNG.


It is said that the cloak draws too much power to simultaneously use weapons.

...which is a terrible explanation seeing as we know cloaked vessels can reach high warp, which one would think bending space and time requires much more power than launching a torpedo. Torpedoes by their very nature are self-propelled and self-guided, even if they are less effective without the launching ship's assistance, one would think simply launching them would be easy.

So the real answer is, in terms of plot, the status quo is almighty and a cloaked vessel that can use weapons freely while cloaked would make a race --or even a single ship-- too powerful to overcome. Such a vessel is not seen until the Reman Warbird Scimitar in Star Trek Nemesis).


In Star Trek III search for Spock the Klingon captain beams to the ship from the planet while the ship is cloaked. Pretty neat trick since they can't use transporters while cloaked

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    Hi @Kidjames, welcome to this website! Even if it can be argued that beaming a klingon on a ennemy vessel leads to some battle quite fast, I am not sure that actually counts as "shooting"... Do you have other examples on-topic? :)
    – Eureka
    Jan 28, 2014 at 7:46

Some can.

In Star Trek VI: The Undiscovered Country, the Klingons built a special Bird of Prey that can fire its weapons while cloaked.

In ST:ENT, the ISS Enterprise from the Mirror Universe is able to fire while cloaked ("In a Mirror Darkly")

According to Memory Alpha:

Due to the enormous amount of power required to generate a cloaking field, there is by and large not enough power available to also power the weapons and shields...However, there have been several times when advances in cloaking > technology have rendered these tactical inefficiencies untrue.

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    This doesn't answer the question.
    – Monty129
    Aug 20, 2014 at 21:10
  • Hi Matt, I took the liberty to move your old answer here, as it was much more detailed. Feel free to roll back if you disapprove. Otherwise, please consider linking to the specific M.A. page where you took the quote.
    – bitmask
    Aug 21, 2014 at 19:00

Chris is 100% correct. The ONLY reason that ships cannot fire while cloaked is because it would seriously damage the plot device. Let's be perfectly honest. Star Trek VI is set in 2293 and the Klingons (whose technology is generally inferior to the Federation's) managed to build a prototype ship even then. It's impossible to conceive that the technology was possible in 2293 but not in 2358 when the Federation had the phase cloak and the Romulans had their D'Deridex Type-B Warbirds with their almost limitless amounts of energy from their quantum singularities. The phase cloak in particular is far more advanced than any Romulan or Klingon cloaking device before or after (since you literally CANNOT be detected or fired upon while phased). With that technology, a vessel doesn't need extra power to maintain a phase, it just needs extra power to change its phase. All that would be needed is for a ship to be phased with its cloak and have smart torpedoes that change their phase to our regular continuum milliseconds before impact. Not only would it hit, but the target vessel would be COMPLETELY unaware that anything was amiss. If done correctly, the target ship could be destroyed with a volley and no one on the target ship would have had time to send out a distress call. In fact, battle is probably more humane this way because the target vessel wouldn't even have time to know anything was wrong until it was all over. See the problem here? The plot device is destroyed before the story even begins. (Although it would have been a great weapon against the Borg.)

Mind you, there is one really good thing about a working phase cloak with these kind of combat tactics. The Galactic Empire wouldn't stand a chance against the Federation with this weapon. Even a single Oberth-class vessel could easily overpower even an Executor-class Star-Destroyer or a Death Star. They can phase their ship through the shields and hull, right to a weak point (like the main reactor). Once there, they could fire one of their "phase-quantum torpedoes" (patent pending :P), sit back and watch with satisfaction as the whole place goes up with them completely safe from the explosion in their phased state. The Empire will never know what had happened. They would have no choice but to chalk it up to technical malfunction and execute a random engineer for it.

I hope that this both informed and entertained you. It's a slow day at work. XD

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