Don’t trust the movies, they are very far from reality. Unless, of course, they are documentaries on Discovery.
1. The pin of a grenade can be ripped out with your teeth
Before throwing a grenade, cool movie characters pull out the pin with their teeth. That’s what Clarence Boddicker did in Robocop, Ray Farrier in War of the Worlds, Dizzy Flores in Starfleet, Casey Bracket in the Predator remake… Clench your jaws tighter, yank a little, and the grenade is ready to detonate. At least, that’s what the fighters claim.
What it really is. You can’t just rip the ring out of the grenade: first you have to open the metal “tendrils” on the other side of the ring with your hand. Without this even a very strong jerk will not move the pin. So, unless you are a terminator with a hydraulic-operated steel jaw, an attempt to rip the ring out of the grenade with your teeth will result in losing those very teeth.
2. Silencers make the shot silent

James Bond and his gun with a silencer. “Casino Royale, 2006.
If the film has a silencer on the killer’s gun, you can be sure that no one will hear the shot, even if they’re standing right around the corner. If the shooting takes place in a place full of witnesses, like a subway station (John Wick 2), the shots won’t attract the slightest bit of attention.
In especially neglected cases, the killer can even do without a silencer. We take a bottle, put a lot of paper tissues in it (like in the movie “Shooter” with Mark Wahlberg), and the sniper rifle shoots with a sound comparable in volume to the snapping of the fingers.
Which is really. A silencer makes the shot quieter, but not so quiet that it cannot be heard. In reality, a silencer is designed to protect the shooter’s hearing rather than to conceal the fact that a shot has been fired.
To make the shooting really quiet, you need special gun models and subsonic ammunition. Simply screwing a silencer onto an ordinary pistol does not make the shot silent. Compare for yourself how different the shots from a gun with and without a silencer are.
3. Defibrillator starts the stopped heart
In the movies, the defibrillator is a kind of magic object that can revive even a person whose heart has already stopped. Sometimes, however, it does not work on the first try, but on the second or third try‑, but in the end it always works.
What it really is. A defibrillator cannot start a stopped heart. This device is used to restore a normal heart rhythm when the heart is beating, but it does this incorrectly. If you electrocute someone with a stopped heart, you will just kill them completely.
4. an injection into the heart will bring anyone back to life

Vincent tries to revive Mia, who has lost consciousness after an overdose. “Pulp Fiction, 1994.
The hero is in critical condition, something must be ‑done urgently‑, and the magic defibrillator is not at hand. The solution? A shot of medicine into the heart! The movies “Pulp Fiction” and “The Rock” clearly demonstrate this method of treatment.
What it really is. In modern medicine, there is such a concept as intracardiac injection, but it is practically not used. There are safer, though not as spectacular, ways to get the medicine into the body. Injecting a needle into the heart will leave a hole in it and lead to severe internal bleeding, which can be fatal. Even if this is a trick worth pulling, it should only be done on the operating table, not at home.
5. A bullet can easily knock down a lock
A padlock is no barrier to tough guys with guns. One pistol shot from a meter away and the shackle shatters. No need for keys or long fiddling with picks.
What it really is. Shooting at a lock with a pistol is not only useless, but also dangerous: the bullet will not do much damage to the wishbone, but it will ricochet and quite possibly kill the shooter. In reality, police special forces use shotguns loaded with special cartridges with loose powder instead of hard pellets to kick out locks and doors. Plus they wear body armor and face protection before doing so.
You can watch how the host of the Demolition Ranch video blog tries to shoot the padlock with various weapons (not at point-blank range, though, but from a safe distance). The experience showed that pistols are no good: a Barrett M82 sniper rifle was needed to guarantee the destruction of the padlock.
6. Ventilation – the way to salvation

John McClane sneaking through a vent. “Die Hard, 1988.
In movies, the vent is a convenient way to quickly and inconspicuously get where you need to go. It’s clean and there’s enough room for a large adult man to fit down the entire shaft and crawl away, hiding from pursuit or, conversely, preparing to ambush the villains. And sometimes the vent may hide not a noble avenger like John McClane or Ethan Hunt, but a sinister alien creature under two meters long, as in the movie “Alien”.
Which is really. Ventilation ducts are not big enough to stick a person in there-at least not so big that they retain the ability to move around. Besides, inside, they are blocked by dampers and valves, and the outlets from the ducts are resting against grilles or air conditioners. It’s also quite dirty and dusty in the ventilation system.
As for the large vertical ventilation shafts (which run from the roof of the building), you can climb into them only with some equipment. But such a way of entering the forbidden territory can’t be called silent.
7. Cars explode every chance they get
If you shoot a car, crash it into something‑, or drop it ‑off a cliff, it will explode. And other cars parked nearby can be blown up as well. Apparently, in the movies they fill the cars with nitroglycerin instead of gasoline.
What it really is. Gasoline itself is not explosive – it is its vapors that are explosive. And car designers specifically design gas tanks so that they do not accumulate there. So a gas tank explosion is quite a rare occurrence.
And setting fuel on fire with a shot is not a trivial task. Ordinary bullets won’t do – you’ll need incendiary or tracer ammunition. The shot car will start to burn, but there will be no spectacular explosion. And in a simple collision, there will be none at all.
8. Arrows are not as scary as bullets

Boromir, who is shot with bows, manages to kill several orcs, and only a third arrow knocks him off his feet. “Lord of the Rings: Fellowship of the Ring, 2001.
According to the filmmakers, arrows and bullets work differently‑. If a pistol shot to the chest is fatal, an arrow from an archer that hits the same spot will not knock the hero off his feet. The brave warrior will continue to fight and only after the third or fourth ‑projectile will fall, give a touching farewell speech to his grieving comrades-in-arms, and retire peacefully to Valhalla.
What’s real. After a bullet wound, you can still, if you’re lucky, retain some mobility. But an arrow is different. It is more than a bullet. An arrow lodged in a wound hurts a lot and keeps hurting you when you move, so you can’t really run around with it. So in some ways it’s more dangerous than a bullet – unless, of course, we’re talking about explosive ammunition.
9. The shot throws the man away
When action heroes shoot their enemies with a shotgun, the victim is thrown back as if he had been hit by at least a cannonball. It was especially funny in Terminator, when Kyle Reese’s shot threw a hundred-pound cyborg out of the bar and into the street.
What it really is. A knowledge of Newton’s third law of motion suggests that a weapon capable of throwing its target a few meters away with the same force as the shooter. The recoil from such a shotgun, if it existed, would hurl the wearer the same distance as the victim, only in the opposite direction.
In reality, bullets, despite their high kinetic energy, have an extremely small contact area. And even if the shot is very powerful, the projectile will penetrate the victim, but it will definitely not be able to throw him away.
10. Piranhas are deadly

Primal predatory fish attacking a diver. “Piranha 3D, 2010.
Piranhas are often seen as monsters in horror movies. They are much more dangerous than sharks, even though they are smaller in size. These fish attack in huge packs and gnaw their victims to the bone in seconds. And if some ‑villain throws you into his pool with piranhas living in it, you will not be saved. You Only Live Twice confirms that.
What’s real. There have been no recorded cases of piranhas killing humans, although a severely hungry predatory fish can bite a person. In fact, their bloodthirstiness is greatly exaggerated: they are more inclined to eat carrion, but not living people. See how the owner of a pond with piranhas on his own example demonstrates their reaction (or rather, its absence) to humans.
11 Chloroform is effective immediately
According to the filmmakers, chloroform is a kind of magical liquid that can be inhaled once to reliably pass out for several hours. It is used by assassins and criminals to quickly and inconspicuously render their victims unconscious and kidnap them.
What it really is. In order for a person to lose consciousness, he needs to inhale chloroform for about five minutes (and all that time he will actively resist). Also, you have to support his chin or his tongue may block his airway. And chloroform can make him vomit.
So the perpetrator would need the total obedience of the victim, enough time, and the skills of an anesthesiologist. If the chloroform is stopped, the person will regain consciousness fairly quickly.
12. A blow to the head is nothing
The hero is hit hard on the head with a fist, baton, gun butt or even a car bumper and loses consciousness. He wakes up a long time later, trapped by the villain. But nothing prevents him from breaking free and escaping!
Which is really. It is impossible to knock a person out so that he wakes up without consequences. If he doesn’t wake up quickly, it means that he was seriously injured, there was a concussion or a brain hemorrhage. And even if the victim wakes up, he will still experience nausea, disorientation and dizziness. No fighting with enemies is out of the question – it’s just a matter of surviving.