Locks usually function just fine, but sometimes they burst open without any obvious immediate cause. In media of course this happens because the plot demands it, though it is occasionally deliberately used by a Con Man. This is typically at an inconvenient or embarrassing time (they grabbed a suitcase identical to theirs but filled with sex toys, which bursts open as they run 15 minutes late to a flight). Sometimes handwaved by having the container stuffed with something (say, money) that presses from inside, but that doesn't account for the timing.
Subtrope of Plot-Sensitive Items and sister trope of Plot-Driven Breakdown; this can be reclosed immediately, though the contents may take some work. Not related to Plot Lock, which is about being forced to progress through the plot in a desired order.
- At the beginning of the first Eden of the East movie, Saki's suitcase bursts open as the cabbie manhandles it, spilling guns and ammo and grenades onto the ground — not hers, but a setup by another character. How they got the suitcase to open at exactly the right time, though...
- In My Little Pony: Equestria Girls Forgotten Friendship, the door to the yearbook office somehow closes behind Trixie and locks itself, just so the joke of her botching her Smoke Out exit can be done.
- In Lock, Stock & Two Smoking Barrels, during the opening Chase Scene, Bacon's suitcase flies open in slow motion and all the money and valuable inside are scattered about.
- In Meet the Parents, Ben Stiller's suitcase gets lost in-flight. A suitcase is found matching the description and delivered to him (at the parents of his girlfriend). He attempts to open it but can't and leaves for the day, leaving his prospective father-in-law alone at the house. Being former CIA he opens it easily and finds it full of fetish and bondage gear and sex toys.
- At the end of It's a Mad, Mad, Mad, Mad World the suit case carrying the money pops open, dumping the cash into a crowd of people.
- The plot of Dumb and Dumber revolves around a briefcase full of money that is accidentally intercepted by one of the duo. It's locked "really well", but nonetheless opens when the two get into a fight.
- At the end of The Killing, the suitcase containing the money bursts open when it falls off the baggage cart when the cart swerves to avoid a dog.
- Cloud Atlas: While being locked up tight, Adam's chest full of gold springs open when used to knock out Dr. Henry Goose.
- Near the beginning of The Silver Chair, Eustace and Jill are escaping from some bullies towards a door that is always locked, and of course it turns to be unlocked. Justified in that Aslan has magically caused this to happen, but they don't know it at the time.
- The Meaning of Liff: Played for Laughs with the definition of the quick-release Adlestrop, a suitcase feature that enables the case to pop open on airport conveyor belts and fling one's underwear into the gearing mechanism.
- Sawyer of uses it repeatedly as a con man, to the point of lampshading when we encounter an alternate universe where he's a cop.
- Hurley falls victim when his suitcase springs open, causing him to miss his flight out of Australia. So he rebooks on the next flight, flight 815.
- The Classic Doctor Who story "Image of the Fendahl" has a part where the Doctor gets locked in a storeroom by skeptical victims of The Siege (in order to prevent him solving the plot too early). He tries the Sonic Screwdriver on it and it doesn't work. The scene cuts to the other characters (some of them die), then to a scene with Leela assuring another character of the Doctor's "great gentleness" and back to him tantruming at his screwdriver and kicking things in rage. Then, there's a sudden click at the door and the Doctor emerges to rejoin the plot, no explanation for who opened the door given. Word of God says that it was a delayed reaction to the Doctor's screwdriver, but the only onscreen implication of this is a short scene of the Doctor kissing the screwdriver, although this could have been a simple apology from him for mistreating it earlier. Word of Dante from Terrance Dicks says that it was a delayed reaction to the Doctor kicking the lock (something that doesn't seem to happen on television).
- The SpongeBob SquarePants episode "Krabs Vs. Plankton". Mr. Krabs is sued by Plankton for slipping in the Krusty Krab, and his lawyer is indisposed, giving SpongeBob his briefcase, which he claims contains everything necessary to win the case. Unfortunately, the lawyer neglects to tell SpongeBob the combination to the lock, so he spends most of the trial struggling to open it. At the last possible moment, the briefcase opens, revealing a Krabby Patty, which is used to lure Plankton out of his ruse and lose the trial.