This occurs when someone loses their grip on their gun, sword, knife, club, baseball bat, etc., either by accident or due to something else. Maybe someone tackled them, or a door got opened into their face, or the Angry Guard Dog decided to sink their teeth into them, or they slipped on the ice, whatever. The weapon will drop from their hands and slide across the floor, sink halfway into the mud, end up under the furniture, etc.
Count on it happening right when they need the weapon the most, and if losing the weapon happens immediately before a fistfight, you can also count on a mad scramble to be the first one to get it. Sometimes, when the weapon is a gun, a third party gets to it first, but you won't know that until a shot rings out and someone crumbles to the floor. Then there will be jump cut to the third person holding the gun, with either a shocked or satisfied expression on their face.
- Put Down Your Gun and Step Away, wherein another person with a gun orders you to drop yours.
- Do Not Drop Your Weapon, wherein you can empty multiple magazines into someone or inflict massive damage through other means, but they're not fully dead until they drop their weapon.
- Where's My Gun?, which is when someone has a favorite weapon and if the fighting starts then they need to find that gun before they can do anything.
Blasting It Out of Their Hands and Left Your Lifesaver Behind are related tropes. The former involves someone else relieving you of your gun through excellent marksmanship, and the latter is when you yourself left your gun behind, instead of dropping it.
- In the anime adaptation of Fate/Apocrypha, Mordred is shown knocking Excalibur out of her father's hand at the Battle of Camlann. This small triumph is short-lived as King Arthur coldly dismisses her before drawing Rhongomyniad and running her through instantly.
- Damage Control is about a company that specializes in cleaning up the mess left over after superhero battles. One issue throws a lampshade on this when the company employees are watching an insanely over-the-top movie based on their exploits.
- John: Bet you twenty bucks he drops the gun.Robin: You're on!On-screen hero: Oh no! I dropped my gun!Robin: (Handing John a twenty) Here.
- The Adventures of Robin Hood: Sir Guy drops his sword while dueling with Robin. Justified in that he was falling down the stairs at the time. Robin gentlemanly lets him have the sword back before continuing the fight.
- A New Hope: The franchise is absolutely littered with tropes, but this one is surprisingly averted in the trash compactor scene. Despite jumping down a chute and getting a hard landing in the trash compactor room, and being grabbed by the creature's tentacles and roughly yanked under water not once but twice, as well as having to struggle hard to get free, Luke keeps a tight grip on his gun throughout the scene. As does Han.
- Blade Runner: Deckard loses his gun. Batty gives it back to him...after breaking his fingers so that he can neither hold it properly or pull the trigger.
- The Bourne Identity: The assassin who comes crashing through the window drops his gun after Jason hits it while they're grappling with each other. Neither one of them attempts to recover it, as they both know their opponent isn't going to give them the time to do so.
- First Blood: Every single cop Rambo fights in the forest drops their gun as soon as Rambo so much as touches them.
- Kill Bill: During the climatic sword fight between The Bride and Cotton Mouth, Cotton Mouth loses her grip on her sword...right after The Bride has sliced the top of her head off.
- The Mask of Zorro: When Don Diego asks Alejandro (who he wants to train to be the new Zorro) if he knows how to use his sword, Alejandro demonstrates several flashy moves, only to have Don Diego easily parry the sword out of his hand once he's finished. Considering that Don Diego didn't put a whole lot of effort into it, Alejandro must have had a really loose grip on his sword...
- The Princess Bride: When Inigo and Westley are fighting, Inigo drops his sword. Westley courteously breaks off attacking offensively and lets him pick it up. Understandable in that neither of them is a bad guy and they're just enjoying a chance to engage in a swordfight with a worthy opponent. After he defeats Inigo, Westley acknowledges his swordfighting skills and simply knocks him out instead of killing him.
- Rambo IV: One of the river pirates drops his gun after Rambo shoots him. Trying to pick it back up gets him a Boom Head Shot.
- RoboCop: Robocop, being a superstrong cyborg, ordinarily wouldn't drop his gun. However, when he tries to arrest Dick Jones, the Corrupt Corporate Executive who's trying to destroy him, his hidden directive that prevents him from arresting a company executive kicks in and he drops his gun. Not that the gun would have done him much good against ED-209. Happily, the next time he runs into ED-209, the directive isn't a factor and he's got a much bigger gun.
- Rob Roy: Rob Roy loses his grip on his broadsword at the end of his climatic duel with Archibald. Archibald uses the opportunity to taunt him before delivering the killing stroke. One burst of Heroic Resolve later, Rob Roy is once again firmly gripping his sword and Archibald has been cut nearly in two.
- It's Archibald who loses his grip on his sword then, but it's kinda justified in that he's just been cut nearly in two.
- Stay Tuned: This is lampshaded when Roy ends up on a channel resembling old film noir. He picks up his revolver only to drop it and have it accidentally go off, which causes his secretary to buzz in over the intercom, deadpanning, "Mr. Knable, you've dropped your gun again."
- The Substitute: The aforementioned substitute is actually a tough as nails mercenary, who's gone undercover into an inner-city high school after his girlfriend, who worked as a teacher there, was attacked and nearly killed. He finds out a gang made up of corrupt school administrators and students is running drugs through the school. In one scene, he's talking to some friendly students in his apartment. There's a knock at his door and he answers it with a gun in his hand as a precaution. Gang members burst in, causing him to lose his gun. A fight ensues, he can't get to his gun, he's outnumbered and about to be killed...then a shot rings out and the gang leader drops dead, because one of the friendly students did manage to get to the gun.
- True Lies: Helen drops the Mac-10 she was using to try and kill the terrorists. Justified in that she's a ordinary housewife who had no idea how to hold the gun properly or handle the recoil. However, the gun bounces down the stairs, still firing, and conveniently kills all the terrorists anyway.
- Harry Potter: Weaponized in the series, as the Expelliarmus spell used during Wizard Duels and in self defense is specifically designed to cause someone to drop whatever it is they have in their hand, usually a wand.
- Repairman Jack: Jack sometimes carries a pistol on him expressly for this purpose. It's not loaded, and sometimes he'll accidentally drop it during a fight, and let the other guy pick it up. He finds it interesting to see what they do when they think they've got the upper hand. Once, an abusive husband whose wife's brother hired Jack to stop the abuse got his hands on it. This was after the wife attacked Jack to protect her husband. The husband held the gun on Jack and his wife, told her how much he hated her, then prepared to shoot them both. When the gun didn't fire...
- The Rockford Files: Jim Rockford didn't carry a gun. He couldn't because he was an ex-convict. However, in many episodes he was shown to be extremely good at tackling or punching or tripping the bad guy who did have a gun, causing them to drop it...then beating the shit of out them to show that the only thing that made them a threat was the gun.
- RWBY: Ruby loses her grip on Crescent Rose while investigating Mountain Glenn with her team and Professor Oobleck. Due to her stubborn refusal to train in hand-to-hand combat, she's quickly captured by White Fang goons she could have easily taken otherwise.
- In Volume 4, Tyrian uses his tail to wrench Harbinger (a scythe) out of Qrow's hand, grinning wildly while expecting a look of shock on Qrow's face. To Tyrian's surprise, Qrow just shrugs and repeatedly punches him in the face until he's close enough to retrieve his weapon.
- In Volume 7, Tyrian once again manages to disarm Qrow of his scythe in the middle of their Mêlée à Trois with Clover after Ironwood declares martial law. Unlike their last fight, Qrow decides to abandon the scythe in order to break Clover's Aura with a punch, allowing Tyrian to snatch it up and use it to stab Clover In the Back.
- In Champions of Far'aus there are a few times when a characters weapon gets wrenched out of their hands during a fight:
- Aquazog disarms Daryl with his pole arm, although Flamel quickly slides the sword back to him.
- Doug looses his grip on his bladewheel when he gets dragged away by a spider-like creature.
- Skyes mace goes flying when she hits a fast spinning metal bladewheel, and her shock allows a skeleton to sneak up behind her with a net.
- Ben 10: Omniverse: Billy Billions comments on this in his debut episode when he keeps losing his grip on his age reversal gun.
- In real life, police officers and soldiers are taught to keep a very firm grip on their guns, to not let anyone get close enough to even have a chance to cause them to drop it, and to keep it holstered or slung at all other times.
- A substantial number of techniques of many martial arts both contemporary personal defense and historical combat arts are focused on affecting precisely this result. In the case of the former, it's much easier to protect yourself and end a threat if your attacker's weapon becomes your weapon. In the latter, it's much easier to make your opponent dead.