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Cannot Cross Running Water

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They just had their horseshoes manicured.
"Now If you doubt this tale is so,
I met that spook just a year ago.
Now I didn't stop for a second look,
But I made for the bridge that spans the brook.
Cause once you cross the bridge my friends
The ghost is through, his power ends."

Like garlic and salt, water is one of the common substances widely held to have special powers. Among other things, this means it can be used to protect against various creepy-crawlies and things that go bump in the night. Putting yourself across some water might be all it takes to save your neck.

Folktales are inconsistent regarding on which creatures this works, but it's generally best against vampires, ghosts, nuckelavees, and witches and wizards. For almost anything else, it's still worth a try. But beware of bridges: depending on the tale, they might be able to cross these or not.

Symbolically, it makes sense for water to work as a barrier against certain monsters. Water is the source of life and so naturally works against the undead. On a practical level, it can also deter predatory creatures that hunt by smell, as water can misdirect or damp scent trails.

There are some variations as to what form of water will work. Almost always, the water must be moving. Rain or the ocean may or may not qualify, but rivers always do. The origin of this may be that Jesus was baptized in a river, but undoubtedly helping the folklore is that running water is safer to live near than stagnant water. Stagnant water doesn't wash away harmful content, is more inviting to mosquitoes and other vermin, promotes mold, and so on. Many of the aforementioned ghosties are associated with disease, so it's logical to interpret the running water to be a barrier against them. Holy Water, of course, packs extra punch, but is less frequently found flowing around on the landscape.

Sub-Trope of Supernatural Repellent. If water is actually harmful to these creatures, you can Kill It with Water. See also Healing Spring, Super Drowning Skills, and Chase Stops at Water. For potential contrast, see Walk on Water, Super Not-Drowning Skills.


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    Anime & Manga 
  • In Black Blood Brothers, this is a weakness some vampires suffer. Jiro can cross water without a problem, but Kotaro is severely weakened and can die if he is submerged.
  • Dorohedoro has a variant- magic users are weakened by rain rather than normal water- and it's specifically mentioned it never rains in the magic-users's world. It's a plot point twice-hinting at a major character's identity and marking the beginning of the end of the manga.
  • Hellsing:
    • Alucard at one point shows his considerable power as a vampire by crossing the sea (on a private jet), while drinking wine, in daylight. Seras, meanwhile, has to ride in the cargo hold in a locked coffin.
    • There's also a later plot point about the need to get Alucard on to an enemy emplacement on a stolen ship, as hampered by the fact that most means of approach would result in him being shot down and dumped in the ocean, rendering him powerless. They solve the problem by opting for a plane too fast and high for it to be detected and shot down before it's directly above the ship. This, however, was All According to Plan: since the plane gets shot down and the ships destroyed, Alucard is left stuck in the middle of the ocean while Millenium attacks London.
  • Discussed in Interviews with Monster Girls regarding how it applies to dullahans. Kyouko and Tetsuo-sensei eventually come to the conclusion that pre-modern dullahans probably gained the reputation because if they dropped their head while crossing running water they'd be pretty screwed.
  • My Monster Secret exaggerates this trope while still playing it for laughs. Vampires in this setting are bothered by any fair-sized body of water, running or not. As with all vampire weaknesses, half-vampire Youko Shiragami's reaction is lessened: she can cross the ocean or swim in a pool, but doing so freaks her out.note  Her full-blooded father Genjirou, however, can't even manage that; in one story he tried to cross the ocean to keep Youko from messing around with boys, but ended up crashing down after a few meters... while saying "Uwow, uwow..."
  • Hazuki has this weakness in Tsukuyomi: Moon Phase, though the only time it really becomes a problem is when she almost drowns in a hotel swimming pool with a whirlpool feature.

    Comic Books 
  • Referenced but subverted in Alan Ford: this comic's version of Baron Wurdalak and his vampiric friends have a weakness based on this concept, though it's soon closer to Kill It with Water, as Vampires here die if submerged, and even being pelted with snowballs is harmful to them.
  • Fiends of the Eastern Front: When the Rumanian vampires begin to hunt their former German allies, Hans buys them some time by throwing a grenade onto a frozen lake, preventing the vampires from following them until it freezes over again.
  • In Kaijumax, the Creature from Devil's Creek, despite the name, can't cross running water or he'll turn into an ordinary, harmless, powerless goat. He's forced to do it by his gang's leader and seemingly executed by the ensuing Giant Foot of Stomping.
  • Parodied in Lanfeust and its spin-offs: Trolls from Troy avoid getting wet at all cost, but their is nothing supernatural about it: they are all The Pig-Pen and water could make them clean (thus alienating the flies they keep as pets). As such, water is often used to contain them, like by teleporting a tribe on a island or creating magical downpours around a building to keep a couple of young trolls in.
  • One Swamp Thing storyline (volume 2, issues #38-39) features a group of vampires that have adapted to living underwater in a stagnant lake. John Constantine explains that the vampire virus is anaerobic; running water is aerated and damages vampires, but they can tolerate stagnant water — and being underwater shields them from direct sunlight. Swamp Thing destroys them by agitating the lake and turning it into running water.

    Fan Works 
  • In Chapter 8 of Harry Potter And The Vampires Assistant, Harry Potter and Ron Weasley are turned into vampires. Harry tries to carry his friend and fly across a river, but Harry's new flight power fails and they both fall into the river. The vampire who turned them has to fish them out.
  • The Sunney Towne Wraiths in I Guess It Doesn't Matter Any More are disrupted by running water, inconveniencing them even if they try to cross by riding in a truck over a bridge, and making it almost impossible for them to cross under their own power.
  • Not the intended use (Zantetsuken Reverse): The fic takes this trope a step further by making direct contact with all shirts of running water being harmful to vampires. For example, Arikado needs to keep the Holy Snorkel on his person to do basic things like wash his hands in a public bathroom, because otherwise his hands will be burned.

    Films — Animation 
  • In Raya and the Last Dragon, water — be it running or still — is the Kryptonite Factor of the malevolent Druun. Anyone in Kumandra who wants to avoid being Taken for Granite by them is forced to surround themselves by water in some way. The main city of Talon is built on stilts over open water, whereas the people of Fang turned their peninsula into an island by way of an artificial canal.

    Films — Live-Action 
  • Vampires in Hammer Horror films can be killed with running water, which is brought up twice in their Dracula series:
    • Dracula in Dracula: Prince of Darkness is defeated when he falls into running water under ice.
    • Use of this trope leads to a rather undignified death for Dracula's vampirized assistant Johnny in Dracula A.D. 1972 when he is killed... by having him placed under a shower.
  • In Headless Horseman, Headless cannot cross running water. As the town of Wormwood Ridge is surrounded by a deep gorge—accessible only by two bridges—this means he cannot leave the town, and the townsfolk have to lure in victims for him.
  • Land of the Dead: Subverted. Initially Pittsburgh is one of the last human cities defended from the zombie hordes because it's protected by rivers on two sides (the third being a fortified perimeter), which zombies are afraid to cross. Eventually an intelligent zombie named Big Daddy dares to take the plunge and leads the rest across the river by walking on the bottom.
  • In Night of the Demons, the demonic spirits residing in the Hull House are unable to leave the premises because it is surrounded by underground streams.

  • In the Fighting Fantasy gamebook The Keep of the Lich-Lord, running water is impassable to all undead. To get round this, the title Big Bad has dammed the river past his fortress. The final battle of the book can be avoided by destroying the dam while he's on it, causing him to be destroyed by the water.

  • This applies to the vampires of Bakemonogatari, but it's worded as them not being able to swim.
  • This is used as a plot-point in more than one of John Bellairs' young-adult gothic-horror novels.
  • Mercedes Lackey's Children of the Night uses the "rivers are natural boundaries between hunting territories" explanation, with the vampire dryly adding that one might as well say vampires can't cross major highways.
  • Discworld: This principle is known, and mentioned occasionally by certain witches and wizards, but doesn't seem to have any real effect.
    • In particular, Reaper Man shows that a zombie can cross the river Ankh because it's so muddy and polluted it no longer counts as water (and so sluggish it barely counts as running). Although admittedly anyone can cross the Ankh, since it practically counts as a solid. In summer, it's been known to catch fire.
    • One of many weaknesses overcome by the de Magpyr family in Carpe Jugulum. The family's patriarch overcomes the neuroses of their kind with self-help techniques. It all falls apart when Granny Weatherwax causes them to relapse.
      Count Magpyr: I should point out that your ancestors, although quite capable of undertaking journeys of hundreds of miles, nevertheless firmly believed that they couldn't cross a stream. Do I need to point out the contradiction?
  • Dracula: Dracula, Trope Codifier for so many vampire traits, explicitly could not cross running water except "at the slack or flood of the tide". He could also only sleep upon the soil of his homeland of Transylvania, but he got around that; apparently the soil in question doesn't have to be attached to the rest of Transylvania...
  • In Melanie Rawn's Dragon Prince series, Sunrunners (faradhi) cannot cross running water without becoming violently ill. Though some can, and it's revealed later in the series that they are come from another race of light weavers called "diarmadhi".
  • In The Dresden Files, water is one of the most powerful magical anti-agents, and running water can cancel out spells easily. In one book, a villain is able to completely disable Harry from spellcasting by suspending him under a sprinkler, with one of the in-series justifications/handwaves being the weaker, or less skilled, you are, the more water affects you. note  Carlos Ramirez is notable in using 'water magic' as the basis for his offensive spells.
  • The Voitusotar in The Farside Trilogy can't cross the ocean without becoming violently ill and dying. This changes when the Nazis trade them sea sickness pills for training in magic.
  • Harry Potter and the Philosopher's Stone: According to Word of God, this belief is the reason Harry Potter's adoptive relatives took him to a shack in the middle of the sea in order to escape the letters he was receiving. Unfortunately for them, there is no such rule in this setting - and even if there was, Hagrid's so big and strong he could probably just row there by himself.
  • In I Am Legend, protagonist Robert Neville is testing various ways to repel and destroy the victims of the vampire plague that he has survived. Reading up on vampire literature, he tries to test the "can't cross running water" thing by setting up a makeshift stream in front of his yard with a garden hose. When night comes, a particularly-intelligent vampire named Ben Cortman notices this, then proceeds to mock him by hopping back and forth across the trough. Neville shoots him in the shoulder.
  • Interview with the Vampire addresses this matter by saying that vampires don't cross running water because they're territorial and streams often serve as natural boundaries for hunting territory.
  • In the original Legend of Sleepy Hollow, the Headless Horseman always vanishes while crossing a certain bridge. When Ichabod is chased by the spirit, he makes for the bridge in the hope that it cannot follow. It does; it's implied this is because it was actually his rival Brom in disguise. Other variations have the Horseman not pursuing Ichabod over the bridge but instead throws his pumpkin head at him.
  • At one point in The Malloreon, the main characters are chased by a horde of flesh-eating creatures called raveners, which only flee when they reach the seaside, not daring to approach the open sea.
  • Averted but discussed in The Merlin Trilogy. Merlin frequently gets seasick, and it is completely mundane, the way lots of people get seasick. However, he considers it embarrassing, so when someone mentions it he tells them that wizards have difficulty crossing water.
  • Invoked in Most Secret by Nevil Shute; a French priest tells the protagonist that this is why the Nazi invaders can't cross the English Channel.
  • My Vampire Older Sister and Zombie Little Sister vampires can't cross exposed water such as rivers or the ocean, but they have no trouble with plumbing or underground water veins (and being on a ship apparently isn't an issue). They lose consciousness if they attempt to cross. This weakness is eventually revealed to be psychological: it only happens if an individual vampire perceives the water to be too much and/or too fast. This means that it's possible to trigger this weakness by making vampires merely think they're surrounded by water, such as by playing the sound of water in an enclosed space.
  • In the Old Kingdom series, the Dead and most Free Magic creatures can't cross running water (unless it's bridged with boxes of grave dirt), and the books follow the logical conclusion that they can't pass under it either, so at least one city protects part of its districts by ringing them with aqueducts. This is implied to be related to the fact that the Afterlife Antechamber the Dead escaped from is a big river. At least some of the Dead are also harmed by rain.
  • Played mostly true to Dracula's standards in Old Scores, but with a variation: if humans have built a bridge over running water, vampires can cross either on or directly over the bridge.
  • In Prince Caspian, it's stated that most Telmarines are afraid of the sea (which is ironic considering their origins). Caspian, and the seven lords he sets out to find, are exceptions to this superstition. The sea turns out to house some dangerous surprises, but the water itself is not actively harmful.
  • In the Scholarly Magics series, witches and wizards become ill on when travelling on water, oceans included.
  • Darke Magyk in Septimus Heap and its creatures don't cross saltwater — especially flowing or tide-influenced one — well.
  • Tolkien's Legendarium:
    • In The Lord of the Rings, when Frodo escapes a pursuing Nazgûl by ferry early on, it won't enter the river to chase him. Later, when all the Ringwraiths attempt to pursue Frodo across the river Bruinen toward Rivendell, the waters rise up and overcome them, drowning their horses and slowing them down significantly. This is because they are under the command of Elrond, who wishes to bar the entrance to Rivendell. In the film adaptation, Arwen achieves the same effect by invoking Ulmo, the Vala who rules over water.
    • Moreover, in The Silmarillion, it is noted that the creatures of Morgoth fear water, because of the presence of Ulmo, the one Vala who remains in Middle-earth.
  • Vampire City parodies this trope. Vampires can cross running water and even ride with or against the current, but only by lying down straight with their arms at their sides and floating across like logs.
  • In The Wardstone Chronicles witches cannot cross running water. When the Spook suspects Alice, who has been straddling the line between good and evil, of being a witch he makes her walk across a small stream. She makes it, but barely.
  • The Wheel of Time:
    • Rain and rivers can deter Darkhounds, but not for long if they have your scent.
    • The same is true for the Myrddraal: they will avoid crossing water if at all possible, but will find a way if their quarry is on the other side.
  • In one of Andre Norton's Witch World novels, a woman revealed to her brother what he had gotten into by showing him he could no longer cross running water.

    Live-Action TV 
  • In Being Human (UK), Tully tells George that, in order to prevent him from wandering too far and possibly getting into trouble, he should try to find a place surrounded on a couple of sides by water, saying he can't cross running water while in wolf form.
  • Game of Thrones:
    • The Dothraki are a human culture who fear to cross the sea because they have a mythological mistrust of any water their horses cannot drink. It's Serious Business when Khal Drogo announces that he plans to cross it.
    • After an army of Wights invades the Wildling settlement of Hardhome, the zombies stop their advance at the shorelines and don't attempt to pursue the fleeing humans into the sea.
  • In the Inside No. 9 episode "The Stakeout", this is one of the clues that Varney is a vampire, because he's insistent about not crossing the bridge even when it would be the fastest way to catch a criminal.
  • Mocked in Kaamelott, where Idiot Heroes Gauvain and Yvain believe that ordinary wolves cannot cross a stream of running water. The Druid Merlin is prompt to call them on their idiocy.
  • In Night Gallery, "Death on a Barge", the vampire's father keeps her on an island because she can't cross running water so she can't escape.

    Myths & Religion 
  • As mentioned above, water is generally held in various folklore as proof against the likes of witches, ghosts and vampires, the idea being that water is purifying and thus can impede or dissolve unholy forces. This gave rise to the trial of water, iudicium aquae, such as used in witch trials (if you floated, you were a witch), which was also used in some regions on cadavers (if it floated, it was a vampire).
  • In Scottish folklore, the Nuckelavee could not cross running water.
  • There is a common urban legend, a variant on the archetypal Vanishing Hitchhiker tale, which tells of a couple driving along when they pick up a girl who is hitchhiking. She asks them to take her home and gives them the address. On the way there they cross a bridge. Upon arriving at the house, they look in the backseat only to see that she has vanished. They go to the house and tell the people there what happened. The couple who live in the house explain that their daughter died a few years ago and many drivers have picked up her ghost asking to be taken home, but the ghost always vanishes trying to cross the bridge over the water.
  • Meta case: the frequency of vampire myths in local folklore drops and thins out as you travel further west in Europe. In fact the majority of European vampire stories, geographically speaking, are to be found in the land lying between two major rivers; the Danube in the west and the Dnieper in the east (which covers Transylvania of myth and folklore, among other places). Famously, there is only a twenty mile gap in central Europe between the Danube to the south and east and the Rhine-Rhone system to the north and west. Effectively, these two major river systems cut Europe in two, leaving only a very small gap in between them for vampires to safely pass. France and Spain have some vampire myths but are more of a "werewolf economy". To cross to the British Isles involves crossing running water with a vengeance — the English Channel. Britain has next to no vampire myths. Ireland, another running water sea away, has even fewer.
  • Pesta, a Norwegian personification of the Black Death plague, usually requires assistance in crossing running water. Not that she'll spare you if you help her.

  • The Residue in Pretending to Be People appears to be repelled by water. Animals and humans alike quickly learn this weakness, with the former sheltering in the river and the latter using plumbing and pools to avoid it.

  • Used in the climax of Robert Burns' "Tam o'Shanter," when the title character and his horse run for the River Doon to escape a legion of witches.
    Now, do thy speedy utmost, Meg,
    And win the key-stane o' the brig;
    There at them thou thy tail may toss,
    A running stream they dare na cross.

    Tabletop Games 
  • Chaosium's supplement All the Worlds' Monsters. The Daughter of Kali can only cross running water at night.
  • Atlantis: The Lost World generic RPG setting. Ghosts couldn't cross running water, but oddly enough vampires could.
  • The witches in Broom Service cannot cross water, even on their brooms.
  • Mayfair's Chill. If a barghest is tracking another creature that passes over running water, the barghest cannot cross the running water until 24 hours after its prey does.
  • Dungeons & Dragons:
    • In 1st and 2nd Edition, vampires can cross running water, but if they are immersed in it for 3 minutes they are destroyed.
    • In the third edition they can no longer pass over running water on their own, but can be carried over it in a container. Vampires made from water-dwelling beings (such as, say, a merman vampire) can ignore the restriction entirely.
    • Inverted with the Velya, an aquatic form of vampire from the Mystara setting. It dwells in the ocean and is unharmed by water, but will be destroyed if fully exposed to air.
    • The locate creature spell doesn't work if there is running water between you and the thing you're trying to find.
    • The module Curse of Strahd references this with its titular vampire lord. Strahd can cross running water, but if he is standing in it at the start of his turn it negates his Healing Factor, meaning the DM will likely try to avoid it if at all possible.
  • While Dracula can cross the ocean in Fury of Dracula, doing so does gradual damage to him the longer he stays out of port (and gives his hunters clues to what route he's taking, as the sea cards are a different colour and there are fewer routes he could be taking).
  • Subverted in Warhammer 40,000: a folk belief is that running water can disrupt sorcery, but a sanctioned psyker says it's BS. The fact that the final ritual to summon a daemon princess is taking place on a mining barge in the middle of the ocean kind of underlines it. That specific ritual did require ground contact (thus the mining rig), but it's a coincidence.
  • Lejendary Adventures: The Cunning Living Dead monster known as a peccant cannot cross running water except at a bridge.
  • In Rifts, not only can Vampires not cross running water, but water in motion is deadly to them in general. Indeed, it is the only other weakness aside from sunlight that can kill a vampire outright. While this has led to many jokes about killing them with squirt guns, this is After the End, where toy stores and plumbing are both exceedingly rare.
  • Thoroughly averted in both the Old and New versions of the World of Darkness.

    Video Games 
  • In 16 Ways to Kill a Vampire at McDonalds, one of the endings requires Lucy to figure out how to flood the McDonald's, which will send the vampire scrambling for the exit.
  • Baldur's Gate III: In Early Access, Astarion the vampire spawn takes acid damage if he crosses running water, and his AI will refuse to cross it as it is identified as a hazard (other characters react the same way to fire or poison clouds). In the full release, immunity to running water is part of the tadpole's package.
  • Battle for Wesnoth: Ghost units and their upgrades are incorporeal and able to fly, so they can move through any terrain with ease... except for water, which slows them down.
  • Castlevania:
    • In Castlevania: Symphony of the Night, Alucard needs a special artifact to go into water unhurt.
    • Castlevania: Lament of Innocence: Big Bad Walter Bernhard imprisoned his vampire servant Joachim Armster in the Dark Palace of Waterfalls after his failed rebellion. The streams of water, acting like acid to vampires and other demonic creatures, guaranteed that Joachim would never leave his accursed prison.
  • Ghosts in Chip's Challenge 2 can phase through most solid tiles, but cannot move into water unless they have flippers. This is different from just not surviving in water — they actually turn away from it in contact as though it were solid, and they don't do this with any other lethal obstacles.
  • In Dominions 4, vampires get this is an explicit weakness. They cannot directly cross rivers, even frozen ones that ordinary soldiers can, decreasing their mobility. They can cross bridges, however; only directly walking/flying over uncovered rivers is forbidden.
  • In Dungeon Keeper 2, vampire units have a unique vulnerability to water tiles. They won't enter them voluntarily, except to fly over them in bat form, and take Damage Over Time if forced into water.
  • Vampires in Legacy of Kain have no trouble crossing bridges or leaping across running water, but the touch of water is like acid to them. The exceptions to this are the Rahabim, (who evolved to live in water at the cost of severe vunerability to sunlight) and Raziel after he consumes Rahab's soul.
  • In strategy game Leylines, undead troops cannot cross rivers, except on a bridge. As one of the main factions (the Regency) relies primarily on undead units, this has strategic implications.
  • Endermen from Minecraft take damage if they step in water or get rained on.
  • Populous: The Beginning uses this as a strategic element. While it's possible to make boats, contact with any body of water is instantly fatal for all beings because nobody knows how to swim. This includes the shaman, despite her near god-like, earth shattering powers. Players with quick reflexes and a good aim are thus able to use the weakest offensive spell (fireball) to launch the enemy shaman to a watery grave. The simple Bog spell has the same effect, turning a patch of land into an impassable deathground temporarily. These properties are part of what makes Terrain Sculpting so important in the game.
  • In Prince of Persia: Warrior Within, the Dahaka cannot cross water.
  • In RuneScape, Saradomin blessed the River Salve to keep the Vampyres from entering Misthalin. It also works the other way, as Count Draynor is unable to make it back across. The vampyres and werewolves cannot just go around the river Salve. The entire country of Morytania is surrounded by an invisible barrier that keeps them from leaving. The River Salve is the just the source of the barrier. And the river actually wasn't blessed by Saradomin. The Seven Priestly Warriors used some form of evil blood magic to enchant the river. It is not revealed what exactly they did, but it probably involved Human Sacrifice.
  • In The Sims 2, ghosts cannot cross water, so an easy way to make sure that ghosts don't enter your home is to surround their grave with water.
  • In Tomb Raider Chronicles, you found a demon who told you to turn off a water mill or something because the water was trapping him.
  • Remilia and Flandre Scarlet from Touhou Project have this among their weaknesses. This was used as the trigger for the Extra Stage in Touhou Koumakyou ~ the Embodiment of Scarlet Devil, when Patchouli conjured a localized rainstorm to stop Flandre from leaving the mansion, which unfortunately also prevented Remilia from getting back home.
  • Used as a handwave in A Vampyre Story to explain why Mona doesn't just turn into a bat and fly away from Baron Shrowdy's castle: the castle is on the middle of a lake, meaning the only way to from is by boat.

    Visual Novels 
  • Vampires in Tsukihime have great trouble with crossing water, even Arcueid, who is more of an elemental embodiment than a vampire. She can do it, but it's a moment of vulnerability and it's noted that she frequently simply teleports across large bodies of water despite this method of travel being quite a bit slower and harder than you would think. Other vampires can cross water as well, but it's something that seems to make them sick or weak. There's one vampire who actually lives underwater, but it's a bit of a tradeoff since Sumire's ability to tolerate water has made her weaker on land.

  • Castlevania RPG has the Sorceress overhear workers talking about building an aqueduct:
    Sorceress: Did I hear something about running water?
    Igor: Fear not, mistress, you will not have to cross it.
    Sorceress: Cross it? I want to bathe in it!
  • Gunnerkrigg Court has a variation on this. The Annan Waters (between the Court and Gillitie Wood) are stated to be an impassable obstacle for magical creatures, but we eventually learn it's not the river itself that's impassable. There's a ghost haunting the banks who attacks anything that tries to pass. Notably, this ghost has no difficulty crossing the river, but she is bound to its shores.
  • Tales of the Questor features this, when Quentyn is being pursued by the Unselighe Fey, who he remembers are unable to cross running water. He learns quickly how little that means when the Fey have the power to instantly dam up the stream.
  • While fleeing a pack of vampires in Thunderstruck, Hayaka jumps onto a moving coal train. When that train crosses a bridge over a river, every vampire except for the leader is thrown off the train as if slamming into an invisible wall. For the leader, she blows up one of the coal cars while he's standing on it.

    Web Original 
  • In Critical Role, the magically corrupted Shademurk Bog in the Feywild is kept in check by the encircling river network of the Gilded Run. The water itself is explicitly magical in this case, but still evokes the trope of evil being held back by running water.
  • Goblins in Pact cannot cross power-infused metal, and water running through metal pipes infuses them with power for that purpose. This makes modern cities close to impossible to navigate for them, and this is (partly, the other reason being that they're bullies of the downtrodden by nature) why they mostly attack homeless and poor people, living in more reachable places.

    Western Animation 
  • Castlevania:
    • The vampire generals talk about this superstition in "Old Homes" when Carmilla brings up attacking a river town. Isaac and Hector are skeptical, while Godbrand, a Viking, denies it, prompting a very Seinfeldian Conversation of what constitutes as "running water" to begin with (Godbrand claims to have taken baths, and the trio bickers over whether he has, or whether that counts). Later, they're seen crossing a bridge with no problem at least not until a zombie bishop blesses the river and floods the bridge.
    • Godbrand, a Viking vampire general who leads an army of fellow Vampires, of course would be the most knowledgeable about the unlikelihood of the water weakness. He quickly points out that the weakness was easily countered by having vampires move further inland. We also see a flashback dream of him jumping into a boat from a cliff. And then there's the question of how he and the Japanese general Cho even got to Wallachia — clearly vampires have no actual problems crossing running water, and at most the issue is Super Drowning Skills exaggerated by superstition.
    • In season 4, a group of impoverished patricians try to defend their sanctum with a channel of holy water again. The vampire Varney simply jumps over, though commenting that it's "nasty stuff". Then again, Varney is not a normal vampire.
  • An episode of Jackie Chan Adventures features a Chi Vampire with this weakness. Unfortunately, it's smart enough to destroy the bridge our heroes were about to use.
  • The Real Ghostbusters:
    • This, as a weakness of vampires, is a plot point in episode "No One Comes to Lupusville", which dealt with a feud between a clan of werewolves and another of vampires.
    • In another episode, "The Headless Motorcyclist", the Headless Horseman has been pursuing Ichabod Crane, as well as the family and friends of all of his descendants for centuries. The latest descendant, a woman named Kate, lives near a bridge for protection, knowing the ghost can't pursue her over running water, though she admits that's no protection for others the ghost might target. The heroes are able to destroy him by tricking him into crossing said bridge by hiding it with a hologram.

    Real Life 
  • This works against various real life animals, including some of our biological cousins the apes, notably Gorillas. In fact this is how speciation often occurs: a population of a species is split into two sub-populations by the formation of a barrier such as a river (or a few individuals happen to cross an existing barrier at one point), and these sub-populations become increasingly different and eventually separate species.
  • This is why much of Australia's wildlife is unique to it: its species have been isolated for millions of years from other life forms. Most marsupials are only found in Australia (or its neighbouring islands; the exception are opossums, which are native to the Americas), while monotremes, such as the echidna, live only on Australia or on New Guinea. New Guinea was connected to Australia until sometime during the Pleistocene.
  • Indeed, if you map out species diversity across the islands of the South Pacific, the variety of animal and plant life diminishes with each "hop" between archipelagos. By the time you reach the Solomon Islands, non-marine mammals (save bats) drop out completely, and Hawai'i didn't even have palm trees until seafaring humans introduced them.
  • Even the genus Homo (human beings) is affected by this to some extent. Homo floresiensis was a species of early human with large feet and short height, and lived only on the island of Flores tens of thousands of years ago. Various parts of the world, such as the Americas and Australia, were not colonized for millennia because of the expanses of water surrounding them. Eventually modern man got to both.