Blown Across the Room doesn't happen in Real Life, thanks to the Third Law of Motion (for every action there is an equal and opposite reaction). So a gun powerful enough to send a body flying would send the shooter flying an equal or greater distance (since the bullet would be slowed by atmospheric friction before hitting its target). But what if the gun was powerful enough, firing a sufficiently large and fast slug, to blow someone across the room? Then the shooter would go flying as well. That's this trope, when a firearm or similar weapon is powerful enough to knock the person firing it down, or actually hurl them through the air.
Basically, it's Blown Across the Room meets Reality Ensues. Subtrope of Law of Inverse Recoil. Related to BFG through Rule of Cool, and Toon Physics through Rule of Funny. The Invoked version is Recoil Boost, defied by Anchored Attack Stance. Contrast Weaponized Exhaust.
- 1941: The anti-aircraft cannon is not secured to the ground the way it's supposed to be. As a result, when it's fired at the Japanese submarine offshore it rolls backwards along the ground and into a wooden building.
- In Captain Marvel (2019), Carol discovers after unlocking her binary state that her blasts are strong enough to blow enemies across the room and herself in the other direction. The first time she blasts someone, she's hurled back several feet into some furniture behind her.
- In Destination Moon, in order to illustrate to Woody Woodpecker (who stars in an animated film to help convince various men of industry to help finance and build the first rocket to the Moon) how rocket propulsion works, he's asked to shoot a shotgun. The recoil sends him flying several feet backwards. This is followed by asking him to blast several times towards the ground (which sends him aloft).
- Ghostbusters (2016): The recoil of the first prototype proton pack sends Abby flying around in an Overly Long Gag.
- Men in Black: Agent K gives Agent J a small, very powerful handgun called a Noisy Cricket. Every time J fires it, he gets violently thrown backwards.
- In Pirates of the Caribbean: At World's End, this trope is Played for Laughs when the midget crewmember charges up a ramp, fires a gigantic blunderbuss, and is thrown back down the ramp.
- ¡Three Amigos!: When Ned Nederlander has his showdown with the German pilot, El Guapo's second-in-command Jefe replaces his normal revolver with a much larger and more powerful pistol. When Ned fires it, he's blown backwards about 10 yards.
- In The Bands of Mourning, gunsmith Ranette makes for Wax an especially powerful shotgun, with heavy loads meant to take out Pewterarms or Koloss-Blooded. Wax describes the shells as nearly as big as a man's wrist. This trope happens twice during a Traintop Battle: the first time is Downplayed, as the bandit firing Wax's new shotgun merely breaks his hand trying to shoot it from the hip. Moments later, Steris tries firing the gun from a properly braced and kneeling position, and is thrown off the train entirely. Later, the gun finally gets used for (more or less) it's intended purpose: Wax fires it at an enemy Coinshot, who is Blown Across the Room without even touching the bullet (he tried Pushing it away from him, but it was too massive and moving too fast, so the Coinshot himself had to move).
- BattleTech: The Heavy Gauss Rifle forces any 'Mech less than 100 tons (the normal maximum weight for a 'Mech) to make a Piloting roll or fall if it moves and fires the weapon in the same turn. Particularly ludicrous on the BZK-F7 Hollander II. It's got the second-worst possible Piloting difficulty to remain upright, and if it does fall, the fall damage is enough to destroy its rear armor (if it lands on its back) and probably score a critical hit, which has a high chance at detonating the Heavy Gauss Rifle which explodes with enough force to gut the 'Mech outright.
- In Cave Story, the level 3 machine gun can propel you into the air (and even lets you hover indefinitely) when you shoot straight down. For some reason, it doesn't recoil that hard when you shoot horizontally.
- In Eternal Darkness, in Edward's chapter, the player can find the elephant gun if they rescue his servants from The Vampire. Because it's such a massive rifle and Edward's a fairly small guy, failing to let him brace himself before firing (by staying in the firing stance for a few seconds) will knock him flat on his ass.
- Get Amped: A few weapons and gears will cause the user to be propelled back when they fire things from it, but the cake goes to Borg-specific gear "EL Expansion" where its strongest attack — a Wave-Motion Gun — will push the user several steps back, possibly into a Bottomless Pit.
- In Kirby Super Star, the boss Marx's Breath Weapon move (where he shoots a gigantic laser out of his mouth) propels him far backwards outside of the screen.
- No Time to Explain features this (and Recoil Boost) as a primary game mechanic, courtesy of the protagonist's BFG.
- Parodied somewhat with Dan's Haoh Gadoken Limit Break in Street Fighter IV: He launches a huge Gadoken forward which also propels him backwards. It's rather powerful for a Joke Character.
- The Force-A-Nature, an unlockable weapon for Team Fortress 2's scout, has the power to launch the Scout across the room if fired. This can be used to quickly escape engagements, or, if fired directly down, to perform a triple jump (as the scout can regularly perform Double Jump's).
- Afterlife Blues has a page with a street thug who got his hands on a man-portable railgun meant to be used with Powered Armor, by a full-body cyborg, or as an emplaced weapon. Hilarity Ensues.
- Spacetrawler: Here, Pierrot fires a handgun while spacewalking, and the recoil sends him flying away from the ship. In the comments below that page, Baldwin admits that he sacrificed realism for humor on that count.
- Hughie X from Jason Yungbluth's webcomic Weapon Brown tries to shoot the Omnicidal Maniac using Brown's sidearm, which is a plasma pistol. Hughie had been warned that this gun "has a kick to it." Hughie was ready for a kick; he wasn't ready for the explosive recoil that sent him across the room and down a flight of stairs. Of course, Brown has a cybernetic right arm, so his pistol's recoil gets mitigated to a "kick."
- Tech Coyote of the Loonatics Unleashed supplies his teammates with heat ray rifles that can be compacted to the size of a tuna can. The Big Guy Slam Tasmanian drops one and steps on it. The gun deploys to full size and starts firing, which acts like a rocket motor, propelling Slam wildly around the Loonatics' headquarters.
Tech: Uncurl your toes, uncurl your toes!
- The Simpsons: In "The Secret War of Lisa Simpson", this happens to Bart when he links up several police megaphones together and then says "testing" into them, creating a gigantic sound wave that destroys the room he was in, and the entire town.
- During the filming of Predator, actors firing "Ol' Painless" had to be braced offscreen so they wouldn't be knocked on their asses, and this was only when firing blanks (and none of the guys shooting it are what you'd call small). Jesse Ventura described it as "like firing a chainsaw."
- Averting this trope is part of the reason why anti-tank weapons have a second hole in the back of the barrel: without it, the rocket would push the gun back when it launched, which would make it more difficult to use.