- Star Wars:
- The Death Star is the ultimate example. It's enormous, cost an insane amount of funds and manpower to build and operate, and its only advantage over large capital ships like Star Destroyers is that it can wipe out entire planets (as opposed to putting down a rebellion while leaving the population and economic centers mostly undamaged), costing further quadrillions worth of economic damage with every shot, and in doing so, promote justified fury and rebellion against the Empire for such crimes against sentience. A battle station the size of a moon does have a massive intimidation factor, which as Grand Moff Tarkin himself noted can be used to keep populations in line, but it's so costly that it could never be mass-produced, thus severely limiting its effectiveness.
- The Imperial Walkers, aka AT-ATs from The Empire Strikes Back are pretty impressive to look at, but when you think hard about it they're just huge sitting ducks for enemy weapons, and the Rebels manage to disable them just by wrapping cords around their legs and tripping them. What happens when the Rebels decide to arm themselves with some serious firepower, like the proton torpedoes they use to kill starships with? This article from Cracked.com points out some of its egregious design flaws. Unsurprisingly, in the EU, they're even bigger targets. Isard's Revenge has four X-wings take down four AT-ATs in as many minutes and take no damage at all).
- That droid missile from the beginning of Revenge of the Sith that targets Obi-Wan's craft. They fire a missile at a ship. It overtakes his ship and opens. Then droids comes out of the missile and start dismantling the ship. This process takes several minutes, and gives Obi-Wan time to tell Anakin what's happened, who then tries two different strategies to successfully save him. The droids end up variously shot (though this blows part of Obi-wan's wing off), knocked off the ship, and taken out by R2. If the missile had just hit him and exploded like any sane design would have had it do, Obi-Wan would've been dead. Even if Anakin's stunt in saving Obi-Wan was far-fetched and a very unlikely scenario, it would certainly still have been cheaper to pack an explosive warhead into the missile rather than a bunch of saboteur droids. That said, the droid missile can be useful if trying to disable a ship for capture or weaken it over time. However, the droid missile would still be too specialized and inefficient for flat-out destroying starfighters.
- Han Solo pointed out that the lightsabers are completely useless in a fight compared to blasters. That's true unless the wielder is a Jedi and even then it still has the range and limitations of a sword while a blaster can be used at range and from cover.
- Darth Vader's iconic suit. Yeah it looks badass and lets him move around and breathe properly, but it's horribly uncomfortable and heavy, making it difficult to move quickly like he could when he was younger. Plus the suit, coupled with Vader's mechanical limbs, prevents him from using the insanely useful force lightening. Vader's physical strength and extremely strong Force connection is the only thing keeping the suit from rendering him a useless crippled invalid. Even worse, it was deliberately designed this way by Palpatine, so he could craft an intimidating right-hand man while still asserting control over Vader.
- The double-bladed rotating lightsabers the Imperial Inquisitors use. They're clearly built with intimidation in mind rather than practicality, meaning that they're very unwieldy compared to normal lightsabers. This is okay when dealing with most enemies of the time, who either have no Force power or are inexperienced padawans, but against a trained Jedi knight they're easily destroyed, leaving their wielders defenseless. This leads to the Grand Inquisitor's death; once Kanan overcomes his fear of the Inquisitor, he easily bashes him back before using standard sabers to slash the rotating saber in two.
- Darth Maul's iconic double lightsaber also functions on the same principle the rotating lightsabers, but without the rotating part. While useful for attacking multiple opponents, it can risk cutting up its own user thanks to its design. The only reason Darth Maul didn't lose any body parts beforehand was because he was just that skilled at using it. Anyone else would have probably lost an arm in the process. Or their head.
- See also the Star Wars Expanded Universe under Literature.
- From The Force Awakens, we have Starkiller Base. Basically, the Death Star cranked Up to Eleven. Carved out of the surface of an entire planet, it drains stars and uses them to destroy entire star systems. While the Death Star II could at least shoot repeatedly, Starkiller Base takes a ridiculous amount of time to charge up while it drains the sun's energy before it can fire. While its weak spot is at least fortified, it makes it evident that the First Order is ridiculously well funded.
- Iron Man:
- Believe it or not, the titular character's armor was like this for a while in the first film. One montage shows Tony Stark repeatedly testing the armor and correcting various design flaws that crop up. Among these problems are the fact that the suit tends to freeze up when Tony flies too high into the sky. This serves as Foreshadowing for the final battle, when Tony—who has already experienced and solved the problem of his armor freezing—lures Obadiah Stane, whose armor is reverse-engineered from one of Tony's earlier models, to that very same height.
- In Iron Man 3, the Mark 42 armor. It's Tony's most advanced suit to date, but it never leaves an unfinished prototype stage, and its ability to deploy piece-by-piece and assemble on the wearer makes it alarmingly easy to break apart. The assembly part was also clearly not well thought out, as at one point Tony gets effectively punched in the jewels by his own codpiece.
- Batman has the Batwing. Looks like another cool addition to Batman's arsenal; a modified stealth jet complete with Gatling guns, missiles and a price tag that had to be somewhere north of $2 billion back in 1989. Has an utterly god-awful targeting system (it's completely unable to hit a man-sized target under ideal conditions) and goes down in one shot from a pistol (which was itself a pretty silly piece of equipment: having a barrel nearly as long as an arm made it awfully hazardous to draw).
- Batman Returns has Bruce's entrance to the Batcave: It involves reaching into a fish tank to open an iron maiden, which retracts it's spikes and dumps him into a slide that carries him to said cave. It gets him there slightly faster than his elderly butler who just takes the stairs.
- How Bruce is able to acquire his gear in The Dark Knight Saga: The military developed incredible technology for one man to effectively wield — as Batman would illustrate — but were too costly to mass-produce, leaving Wayne Enterprises to stockpile the prototypes under Lucius Fox's watch at R&D. One example from Batman Begins is the advanced body armor that Bruce turned into the Batsuit. Reinforced joints, tough enough to stop a knife, and bullet-resistant, but:
Lucius Fox: Bean counters didn't think a soldier's life was worth 300 grand.
- The Incredibles: One of the more well known lines from the movie: "NO CAPES!"
- The Jackhammer Massacre; it's cool and certainly mangles well, but is shown to be heavy and awkward to wield, and is severely limited by its need for an extension cord (the killer is basically beaten when it's unplugged).
- The Enforcement Droid (ED) 209 from RoboCop (1987). It's a badass-looking walking mech with machine guns for hands, and one of the most awesome-looking things in the movie. But it was rushed out and unfinished, leaving it with a lot of design flaws, including the inability to use stairs, the inability to right itself when it's fallen down, and a programming flaw that keeps it from realizing when a suspect has surrendered. ED-209's impracticality was what led to the creation of Robocop. ED-209's model designer envisioned OCP's engineers focusing on making the robot look good/intimidating before making it work well, "just like an American car". Based on some dialogue from Dick Jones, it seems this was partly intentional. The plan was to make millions selling a defective machine, then make even more millions charging customers for frequent repairs.
- Kiryu from Godzilla Against Mechagodzilla and Godzilla Tokyo SOS. On the one hand, he's a giant cyborg version of the original 1954 Godzilla complete with missiles, Arm Blade, and an "absolute-zero" cannon. On the other hand, he can only be used for a few hours before he needs to recharge, his "absolute-zero" cannon cannot be replaced if it's destroyed, and he will start acting like his flesh-and-blood counterpart if he hears Godzilla's roar. Having a battery life of two hours would put it here as well, much less if the absolute zero cannon is fired. It can be recharged but it requires all of Tokyo's power to do so.
- The Götterdämmerung in Iron Sky. The Moon Nazis' (It Makes Sense in Context) flagship is several orders of magnitude larger than any other ship in their arsenal. Its cannons (firing Depleted Phlebotinum Shells) are capable of tearing enormous chunks of the Moon with a single volley. It doesn't appear to have any other weapons to defend itself from smaller attackers (and its main gun's targetting system is too slow). The Bridge is exposed. To top it off, it's way too complex for the primitive Nazi computers to run. Luckily, a single smartphone can succeed where a room-sized ENIAC clone will fail. The Moon Nazis' goal is to conquer Earth, not render it uninhabitable. So why build a weapon that can do the latter but not the former instead of using those same resources to double the size of their fleet?
- Looper Features a number of examples:
- About 10% of the population are "TK", or telekinetic. It sounds cool, but in practice most of them can't do any more than move small objects with their hands. Joe lampshades the subversion of usefulness, noting that when it was first discovered, everybody thought there would be superheroes and stuff like that, only for it to amount to nothing but idiots who think they're blowing your mind by floating a quarter an inch in the air. However, the future Big Bad, The Rainmaker has the power to do this on a large scale, so the trope is subverted.
- The Blunderbusses, the signature weapon for Loopers, are big and badass looking shotguns that can kill with a single shot easy and have awesome accuracy... as long as you're about five feet or so away from the target. Any further and the accuracy turns to shit, making it almost impossible to aim. Plus it's so big that it's unwieldy as hell. Contrast that with the Gat, which has pretty much all of the Blunderbusses strengths with none of the flaws (it's a lot easier to aim and can be carried with one hand). Kid Blue even points out how much smarter of a choice the Gat is.
- Seth's bike. It's a sweet-looking hoverbike that's fast and fancy, but it's also a pretty old fixer-upper so it keeps stalling and malfunctioning when you try to start it. It's also a little too fast for it's own good; Kid Blue ends up using it in the climax to catch up to Joe and Old Joe, and is killed because he was going so fast he couldn't aim to hit Joe and couldn't brake in time to keep from ending up in the range of Joe's Blunderbuss.
- The powered suits from GI Joe The Rise Of Cobra, as demonstrated in the Paris chase scene. They can't catch up with a vehicle that is weaving through heavy traffic. After the chase, they can't even properly catch up with two people on foot.
- In Operation Lovebirds, Frede's pistol can fire both forwards and backwards. However, he has a difficult time telling which setting is which.
- In Sergeant Bilko's Hover Tank, a tank that goes anywhere a hovercraft can, but one shot from its cannon causes it to recoil wildly.
- The war rhino in 300 is certainly quite impressive, but it gets killed by a well thrown spear before it even has a chance to reach the Spartan front line. Furthermore the war elephants, which the Spartans manage to push off the cliff. note
- Emmet's plan for a double-decker couch in The LEGO Movie. It's a cool idea, and lets six buddies hang out and watch the game. But if the guy on top centre wants to get down, how do they do it without climbing over the guys next to him? And do the people on the bottom couch get a clear view, or do they just watch three pairs of dangling legs? It's Played for Laughs, of course.
- Into the Storm (2009). The idea of turning ships into icebergs to disguise them sounds brillant at first, but then...
Ismay: Icebergs travelling in formation, sir? At a steady eight knots?Winston: We'd have to work on the details..Ismay: ...And with smoke coming out of a funnel?
- Averted by James Bond in Skyfall in the final battle sequence. Yes, his father's hunting rifle is obscenely powerful, and an Ancestral Weapon besides, but come a gunfight with armed mercs with modern assault rifles, Bond fires it twice, kills two goons, and uses one of their guns for the rest of the sequence.
- In Chappie, there's the Moose: an impressively armed mech, capable of taking out aircraft and enemy bunkers. Moore, its creator, wants to sell it to... the South-African police. Who proceed to point out that such a thing is overpowered and and unwieldy compared to the Scout police robots, especially considering that most of the crime in the city is stuff like mugging and carjacking. In addition, when the Moose does get deployed, sure, it's powerful, but it's very poorly armoured, its cameras are susceptable to normal gunfire, it's slow moving in both land and air, and it only takes a few hits from a grenade launcher and a grenade before it's destroyed.
- In The Men Who Stare at Goats: A man lifting bags of sand on hooks hung through his scrotum is asked by a witness:
"Uh, sir, what is the practical application of this?"
- Who Killed the Electric Car?:
- Hydrogen cars are portrayed this way: an exciting new alternative, but one that is inefficient, costly, and distracting from more reasonable solutions to energy problems like better fuel economy standards.
- The Sunraycer, a solar powered vehicle, was very awesome, winning a race across the Australian Outback, but very impractical, being a one-seater that could only work in a desert. But it inspired GM executives into producing a practical electric car.
- Mad Max: Fury Road:
- Subverted by the infamous Doof Warrior◊. The guy does look absolutely ridiculous, but it turns out he actually works as a sort of war drummer for the Warboys, playing inspiring music and even allowing Joe to give his boys orders in a world with no radio communication equipment.
- The refinery on the back of the Gastown rig gives it a very distinctive appearance and allows the People Eater to refuel other vehicles while charging about, but it's revealed during the final battle that carrying around massive quantities of highly flammable substances in a world full of things that explode is decidedly unhelpful when it comes to not catching fire in spectacular fashion.
- In Jurassic World, Hoskins plans to militarize the I. rex, a vicious, Nigh Invulnerable creature that's destroying everything in her path. The idea of militant dinosaurs may sound cool, but they're also wild and difficult to control, making them useless in combat, and a danger to everyone around them.
Awesome But Impractical / Film
"A "cool" tool that is not very helpful."