Rule of thumb: if the narrative in any action, mystery, or genre work draws attention to the fact that the ice over a body of water has just formed, chances are good someone will fall through that ice before the story is over. Ice-cold water being what it is, there's a fifty-fifty chance that character will then drown or freeze. If there's a close-up of an actual warning sign, it is in fact almost an unspoken guarantee that someone will ignore it.
Possible variations include being unable to get a solid grip on the surface ice or getting turned around underwater, creating a kind of natural Drowning Pit. Even if the victim does manage to break through to the surface, or if they're pulled out and rescued, there's still a strong possibility they may succumb to hypothermia, pneumonia, or otherwise catch their death of cold.
People rarely walk on ice by choice, thin or otherwise, unless there's no alternative — the bridge is out, or they're being pursued. While occasionally a character in fiction will stumble out onto snow-covered ice without realizing it, it's far more common for them to know exactly the risk they're taking, so that their death or misadventure is partly on their own heads: it may be An Aesop about how they were too stubborn or headstrong, possibly someone who pushed their luck too far too often, or maybe they were just too much of a Cloudcuckoolander to really appreciate the danger.
In lighter works a character skating on thin ice is a common sight gag. In this case, expect Harmless Freezing to be in full effect, and in a cartoon, the character may immediately bob out of the hole as an instant ice cube.
A subtrope of Chekhov's Gun. Often the outcome of going over an Inevitable Waterfall in winter. Compare A Crack in the Ice, where a character falls through ice or snow into a crevasse. See also Failures on Ice. Contrast Frigid Water Is Harmless, where falling into near-freezing water is no big deal at all.
As this can be a Death Trope, all spoilers are unmarked. Proceed at your own risk.
- Lamput: In "Snow", the combined weight of Fat Doc and half of Lamput causes the ice below them to start to crack. Lamput taunts Fat Doc by nearly letting the ice crack, but he goes away and a single leaf is what makes Fat Doc fall into the cold water below instead.
- In one Archie Comics story, Reggie bets Archie that he can skate across a pond, despite the "Danger - Thin Ice" sign posted. Reggie proceeds to skate fearlessly, since he'd paid a little kid a quarter to put up the warning sign. But when the kid shows up at the pond late — complete with fake sign in hand — Reggie has a major Oh, Crap! moment, just before falling through the ice.
- In Striker, this is how the real Kurt Panzer died - he was forced to walk across an icy river by a bully, and when the ice broke, the bully just watched (and made his friend Klaus watch too) as Kurt drowned. Klaus proceeded to beat the bully to death with a tree branch, and was so traumatised by the whole ordeal that he repressed it for years and ultimately came to believe he was Kurt Panzer, going on to enjoy the successful soccer career that his friend had deserved to have.
- Wonder Woman Vol 1: Hypnota tries stringing a trip wire across a thinner patch of ice when she learns Wonder Woman is coming to a Holliday Girls hockey game with the intent of committing a murder that looks like an accident. While Diana does trip and fall through the ice, as an Amazon it doesn't really phase her and instead of trying to find the hole she fell through she just punches her way through a different spot in the ice.
- Garfield: played with in ''this strip. There is a warning sign for thin ice, but the section Garfield and Arlene are standing on should still be safe. But since Garfield is so heavy, it makes no difference and he falls through it anyway.
- A one-panel strip in Gaston Lagaffe shows him having fallen under the ice, with mademoiselle Jeanne watching in horror. Thankfully he's wearing SCUBA gear, but has trouble finding the exit...
- The "Once Upon a Wintertime" segment of Melody Time is about two couples — a human boy, his girlfriend, a rabbit and his girlfriend — playing in a frozen river. Both couples break up and the girls walk away, passing a "Danger - Thin Ice" sign. The boy rabbit sees the sign and tries to show the girls, but they ignore him, so he sticks the sign into the ice in a fit of rage. This causes the ice to crack, and the girls end up on an ice floe headed for a waterfall, with the boys trying to rescue them.
- In Ice Age: The Meltdown, the Pack go up the glacial wall that surrounds their valley and find out that the top is very thin when Diego, who is afraid of water, falls through. Turns out the glacier has melted into a reservoir held back by an ever thinning dam of ice that threatens to burst open and flood the entire valley.
- In Balto, the main character fights a bear over a frozen lake that then gives way. Balto ends up trapped under the ice and has to be saved by the polar bears Muk and Luk, who until then did not know how to swim.
- In Rise of the Guardians, Jack falls through thin ice and drowns after becoming trapped under it when saving his little sister from the same fate while they were ice skating.
- In An Angel for Christmas, the kids walk on ice when cutting down a Christmas tree, the ice inevitably cracks, and they lose the tree in the river.
- Crouching Tiger Hidden Dragon: Sword Of Destiny: Silent Wolf's battle against Iron Crow and Wei-fang takes place on a massive pool whose surface is frozen by a thin layer of ice, which cracks and spreads apart every second as each combatant tries lunging at each other. Wei-fang ends up falling through the ice and into the freezing cold water, until Silent Wolf pulls him out seconds later.
- The Dark Knight Trilogy:
- In Batman Begins, as part of Bruce's Training from Hell, Ducard breaks the ice underneath him and plunges him into the icy depths.
- In The Dark Knight Rises, Bane's Kangaroo Court sentences people to death by exile, which is implemented by forcing the defendants to walk on the thin ice of the river until they fall through and are swept away by the currents.
- Harry Potter: Harry is nearly drowned by the horcrux in Slytherin's locket when he breaks open a hole in a frozen pond in the Forest of Dean and jumps in to retrieve the inconveniently placed Sword of Gryffindor in Harry Potter and the Deathly Hallows.
- In Jumper, David discovers his teleportation abilities when he goes to retrieve something that bullies threw onto the frozen river and falls through, then panics and finds himself and several gallons of the river water in an aisle of the library.
- In It's a Wonderful Life, the first flashback we see is to George's childhood where he rescues his younger brother Harry after he falls through the ice. In the alternate universe where George was never born, it's revealed that the same thing happened, but Harry died because George wasn't there to save him.
- The iconic climax of Way Down East is a variant — Anna runs across an ice-covered river in a snow storm, and passes out due to hypothermia on top of a small ice floe. David runs out to rescue her, jumping from ice floe to ice floe, but the ice keeps breaking up, threatening to separate both of them and wash them over the Inevitable Waterfall that lies beyond.
- King Arthur: A huge battle scene occurs where Arthur, Guinevere, and their allies takes on an advancing army of Saxons on a massive ice pool. When the Saxon army proves too much for Arthur and his troops to handle, the battle culminates with Dagonet, the largest and strongest of Arthur's men, pulling a Heroic Sacrifice by using his axe to smash the ice's surface, sinking himself and most of the Saxon army into the freezing cold water to their deaths.
- Invoked early on in The Snowman (2017) when the mother commits suicide by driving her car onto a frozen lake. Watch it here. Creates a Bookend to the climax in which the villain dies by breaking through the lake's ice too.
- The film adaptation of The Dead Zone shows a premonition the hero has about three boys falling into ice and drowning due to wearing heavy hockey equipment during a game.
- In Alexander Nevsky, the Rus are preparing to meet the invading Teutonic Knights on Lake Chudskoenote when Alexander is warned that the ice is thin and might crack. In response, Alexander notes that the Germans' armor, not to mention their warhorses, are heavier than those of the Rus, with the implication that the invaders are at greater risk from the ice's condition. During the ensuing battle, the famous "Battle on the Ice", the retreating German force blunders onto or is driven onto a section of the lake where the ice is relatively thin, and many of the knights drown when the ice gives way.
- In The Good Son, Henry exploits this trope when attempting to kill his little sister while they're ice-skating, pushing her into the thin area where the ice cracks and she falls in.
- In Frozen River, the protagonists smuggle immigrants from Canada into the US by driving them over the frozen St. Laurence River. Naturally, the ice eventually breaks and they are forced to flee their car on foot.
- Harry Potter: In Harry Potter and the Deathly Hallows, Harry intentionally breaks a hole in the ice over the pool in the Forest of Dean and swims through the icy water beneath in order to retrieve the Sword of Gryffindor.
- In Uncle Tom's Cabin, Eliza dramatically escapes slavery by crossing over the partially frozen Ohio River, jumping from ice floe to ice floe, with the ice threatening to give in the whole time.
- The Poet: In the backstory. Crime reporter Jack McEvoy is haunted by the death of his older sister, years ago, when they were children—she dashed out onto thin ice to rescue him and fell in herself. So when his brother Sean kills himself Jack is driven to write about his brother's suicide.
- In The Dolls From Doll Street, the story "Sliding on Thin Ice", has the dolls fall through some thin ice. They did see a sign which said, "Danger, No Skating", but (not out of deliberate Loophole Abuse, they were just naive) thought that sliding without skates was OK. When Bernard the dog saves them, he tells them off, saying that they should know not to skate or slide on thin ice, but they pointed out that they didn't know it was thin ice, as the sign didn't specify.
- In the A Smart Girls Guide To book "A Smart Girl's Guide to Sticky Situations", one page teaches you to survive a fall through ice.
- Warrior Cats:
- Flametail decides to go play on the ice with some other members of his Clan. The ice shatters, and he falls through, drowning. Jayfeather attempts to save him, but is stopped by Rock, and so though Jayfeather lives, Flametail dies.
- In an earlier book, Graystripe tries to catch a vole over an icy river and falls through the ice. He ends up being rescued by Silverstream.
- Happens to two of the protagonists during the harsh winter in 'Lost Stars' - Rootpaw earlier in the book, and later Bristlefrost. Both end up being rescued.
- In Little Women, Amy tries to join Jo and Laurie at ice-skating. Jo, who is still extremely angry over having all of her writing burned by Amy, declines to warn her that she's getting near a dangerously thin patch. Amy plunges through, and Jo is immdiately guiltstricken and bolts to rescue her.
- In The Sight, Fell falls through ice and drowns but he later turns out to not actually be dead.
- On Fargo Season One, this is how weak-willed Villain Protagonist Lester Nygaard meets his end — running from his final comeuppance and over the repeated warnings of the police, he charges out onto the middle of the frozen lake, falls through and drowns. Of course, running on thin ice is a fairly apt metaphor for what he's been doing since murdering his wife in the first episode.
- In the season 1 finale of Riverdale, Cheryl is Driven to Suicide due to the recent death of her twin brother. The others try to stop her, however she still accidentally falls through the ice.
- In the Korean Drama Mirror Of The Witch, Seori falls into an ice-covered lake while being pursued by the bad guys. She ends up trapped under the ice and struggling to escape, leading to a cliffhanger ending to the episode. As shown in flashbacks after the Time Skip that follows, she is able to escape due to a combination of the activation of her shaman powers and a fortuitous rescue by her bodyguard.
- In the I'm No Fool episode "I'm No Fool With Having Fun", it talks about how it's foolish to skate on thin ice as you may drown.
- In Through the Dragon's Eye, Gorwen encounters a sign warning of thin ice. Thanks to the literacy skills he's developed through the series, he's able to read it and avoid the danger.
- The Outer Limits (1995): In "Nest", Matt Archer was sucked under the ice and died while playing hockey with his brother Robby and their friend Jack Burrell.
- The Metallica song "Trapped Under Ice", which involves someone falling through a crack in an ice sheet and drowning/freezing to death.
- As does Kate Bush's song "Under Ice", which goes from a picturesque story about skating to pure Nightmare Fuel in under two minutes.
- Pink Floyd used it as a metaphor in The Wall.
If you should go skating on the thin ice of modern lifeDragging behind you the silent reproach of a million tear-stained eyesDon't be surprised when a crack in the ice appears under your feetYou'll slip out of your depth and out of your mind with your fear floating out behind youas you claw the thin ice.
- This can happen in Conquests of Camelot while you're crossing the frozen lake. You need to use either the Lady of the Lake's crystal heart or Gwenhyver's magic rose to get across safely.
- The Cold Open for D4 begins with a young girl walking out onto a frozen river or lake, in plain sight of her father. She wanders up to a snowy owl just before the ice begins to crack underneath her. Then the scene cuts away — a decade and a half later, that girl, Peggy Oldmann, turns out to have been the murdered wife of Defective Detective David Young, with the opening flashback serving to give the audience some idea of what she might have been like before her death.
- In Sonic Adventure, in Big's section of Ice Cap, there are thin ice spots that Big can open when he either jumps on them or tosses boulders at them. Under the first one is where Froggy is found, and these thin ice spots also lead to secret passages where bigger fish are stored. These fish are needed to complete the B and A rank missions.
- 102 Dalmatians: Puppies to the Rescue: In the level "Ice Festival" there is one spot of ice that is thinner than the rest. Nearby is Jasper who is fishing. Domino or Oddball (whoever you are playing as) will surprise him and lead him to the ice. Jasper notices the sign upon stepping on it and slowly moves off of it to avoid cracking it any further. Then your puppy barks at him to further provoke him, he runs back onto the ice, and the ice breaks, sending him into the water and freezing him.
- One puzzle late in Penumbra: Overture involves crossing a frozen lake called Lake Utuqaq to find a hand clutching a crowbar on the other side. Because the ice breaks into floating geometric chunks when Philip tries to cross it, Philip has to either balance himself on the pieces, or use debris to bridge the gaps. A note left by a dead explorer named Joe Freeman also outlines the symptoms of falling in frozen water.
- An early act in Fahrenheit has Lucas seeing a child walking close to a pond covered in ice and know that the child will fall into it. They do, and Lucas has to decide whether to risk police notice to save the child.
- Batman: Arkham City: The icy pool with the shark in the Iceberg Lounge has thin sections. Batman uses an "ice thickness scanner" to traverse it.
- In Stand Still, Stay Silent when Emil and Lali are separated from the group and trying to catch up, they end up chased out onto ice by trolls, at which point Emil falls through the ice almost immediately since he's bigger than Lali and carrying a lot more weight in equipment.
- In this Wally and Osborne strip, Osborne falls through the ice when ice skating on a pond despite the clear "THIN ICE!" warning sign.
- Doug: In "Doug's Christmas Story", Porkchop notices a sign on a pond warning about thin ice and tries to get Bebe off of it, but he accidentally bites her and the populace assumes he meant to deliberately attack her. Much later, everyone goes to the pond to retrace the incident and Porkchop finally brings attention to the sign just before Bebe falls through; of course, Porkchop saves the day and is vindicated.
- The Loud House: In the episode "Snow Bored", the kids try to convince brainy Lisa that snow days are f-o-n fun, Lola tries to show Lisa how enjoyable figure skating is. Lisa makes fast calculations in the snow to predict when Lola will fall through the ice. She's a second off.
- Scooby-Doo, Where Are You!: In "That's Snow Ghost!", Scooby and Shaggy, while riding a toboggan, crash into a sign reading "DANGER - THIN ICE". They end up taking a dip in the water and are subject to Harmless Freezing.
- In the Thomas the Tank Engine episode, "Terence Breaks the Ice", Terence takes a shortcut across an icy pond to collect a Christmas tree needed for the Earl of Sodor's Christmas party. Terence's weight causes the ice to break, and Terence begins to sink into the pond. It's up to Thomas to pull him out before he sinks completely.
- The closing gag of the Josie and the Pussycats episode "The Midas Mix-Up" has Shipping Torpedo Alexandra send her cat Sebastian to trip up Josie while she and Alan are ice-skating together. Sebastian, however, slips on the ice and begins sliding out of control. In a panic, he deploys his claws and starts cutting grooves in the ice as a braking mechanism. As Fate would have it, his claw grooves encircle Alexandra, who hears the distinct crackle of failing ice just before her section gives way. She falls into the water, which results in nothing worse than an Everybody Laughs Ending.
- Alfred J. Kwak: In episode 5, which takes place in Alfred's youth during winter, after Alfred goes missing and his adoptive father Henk (a mole) sets out to find him, he encounters a frozen lake with a sign warning about thin ice, and worries that Alfred fell through the ice and drowned. Alfred actually fell into an empty well with the school bully Dolf and is stuck there, before they're discovered by the hungry cat Krabnagel. In the climax, Henk saves Alfred by distracting Krabnagel, who then pursues him onto the ice and because of his much larger weight ends up breaking it. However, Krabnagel survives thank to Harmless Freezing, as he returns in later episodes.