Hard Head

""If my head were any harder, you could use it for a cannon ball.""

- Pazu, Castle in The Sky

Concussion? What's that?

A subtrope of Made of Iron, perhaps its most common usage. Whether in a Tap On the Head situation, Use Your Head, or any other, The Hero, the villain, the assorted small fry all spring back from the head injury without further ado -- unless Easy Amnesia is needed. (Which will only be retrograde amnesia. He will have no memory problems with events after the injury.)

All right, you can also have Circling Birdies if you want. But nothing else.

NOT Truth in Television at all. A blow to the head is probably the least effective way to humanely render someone unconscious. Injuries from even relatively light blows can be serious, permanent, or even fatal. Whether or not you'll actually knock the person out is something of a crapshoot, as well. As a rule of thumb, anyone who's involuntarily unconscious for more than a few seconds needs immediate medical attention to ensure they don't have a subdural haematoma or some other time-bomb of a brain injury.

See How Many Fingers. The Hard Hat may be the reason for this.

Can sometimes be justified in cases of alien biology, superpowers, or artificial enhancement.

Not to be confused with Hollow Sounding Head.

Anime & Manga
"Krillin: I hope he's got a seat belt in [the Saiyan Space Pod].
 * Killy, the protagonist from Blame, takes more physical punishment than any normal human would ever be able to survive. Most notably in one chapter, where he gets half his head blown off. It has its consequences, naturally, but he still gets better.
 * In one episode, Sailor Moon is thrown upside down into the air and hits the ground with her head without any lasting consequences. To be fair, all Sailor Senshi are regularly tossed around by the Monster of the Week and usually don't sport any visible injuries, but that example was particularly jarring.
 * Averted in Black Lagoon when Revy actually gets a concussion, rendering her non-responsive for about a whole episode, during her fight against . Granted, in the anime it took no less than a near-direct hit with a grenade launcher (just an armor-piercing round to the shoulder in the manga), but still...
 * Not to mention the fact that she fully recovered less than an hour later, immediately after being in a car crash.
 * The Saiyans from Dragonball Z generally seem to have this, although Goku -- despite the Easy Amnesia he suffered as a child -- seems to be a notable case, and it was commented on multiple times by other characters, including fellow Saiyan Vegeta.
 * He did beat a guy in a combat robot suit by headbutting it.

Yamcha: Why? To protect the ship from Goku's head?"


 * Ryōga Hibiki of Ranma One Half. Even for someone who uses Supernatural Martial Arts, he's considered insanely tough. His most well-know "technique" is the Bakusai Tenketsu, Training From Hell in which he slammed himself face-first into boulders so much that he toughened up way into the higher grades of Made of Iron. There was one gag where he headbutted a concrete pole so hard that he not only dented it (noting that it didn't hurt in the slightest), but it actually cracked in half and fell on his head with enough force to shatter into pieces after he turned around. This resulted in a Cranial Eruption and him commenting that it hurt a little. In at least the anime version of the "Waterproof Soap" story, after Ryōga's apparent "cure" has been revealed, Ranma casually lifts a huge boulder and slams him on the head with it, only for Ryōga to pop back up, completely oblivious, causing it to flip over and crush Ranma instead.
 * In the manga Ironfist Chinmi, one of the first minor opponents that Chinmi fights are a pair of identical twin martial artists called the Stonehead Brothers. They've taken this trope and made a form of Martial Arts and Crafts based around it.
 * Yu Yu Hakusho: Yusuke Urameshi displays this, most notably during the Dark Tournament when an opponent tries to incapacitate him with a large rock. Not only does this only barely stun Yusuke, the rock crumbles to pieces on impact.
 * It got started way back when he was still a Badass Normal. When Yusuke gets into a Bar Brawl during an attempt to rescue Keiko from a rival school's gang, one of the Mooks hits him over the head with a beer bottle. Yusuke basically says "ow", then complains about the guy wasting good brew.
 * Possibly subverted in Wolfs Rain: Following, Darcia violently and repeatedly smashes his head against the wall of his palace. He eventually goes insane, but not before seemingly recovering completely from the head trauma with no ill effects.
 * His insanity may instead be the result of.
 * Doraemon always do this as his Finishing Move against the Big Bad in the movie (some of them). Justified since Doraemon is a robot after all.
 * Appears in Tokyo Magnitude 8,
 * In an episode of Sayonara Zetsubou Sensei, the girls go to break Sensei out of government confinement using their respective skills. The Apologizes a Lot girl, Ai Kaga bangs her head on a security person every time she bows to apologize, and kills tons of people through the hardness of her head.
 * Naruto gets his head slammed into the ground a few times in the series. Most of the time, his Kyuubi state reacts to the trauma.
 * Pain, holy shit, Pain. In Naruto Shippuden 167, he was punched in the face, hammered into the ground by a 5-10 ton boulder, and thrown with incredible force head-first into a cliff, courtesy of Naruto. And he didn't get even a scratch.
 * Considering he's practically undead, that makes sense of why he didn't die.
 * The fairly strong Jugo punched Killer Bee right in the face (and followed it up with a rocket boosting, but Bee appeared to have dodged that somehow), which doesn't slow him down at all.
 * Sakuragi from Slam Dunk has a really hard head. His most well-known fighting move is his headbutt. It doesn't even hurt him when he headbutts the floor of a basketball court with all his might.
 * Black*Star from Soul Eater once fell from the sky and landed head-first in a crater and comes out unscathed.
 * While it is never officially stated, in Saint Seiya the eponymous Seiya is hit in his head very often. And by "very often" we mean every single time there's an unstoppable, all-powerful technique used on Seiya, it'll unerringly hit him in the head. And in fact he usually seems to be more affected by attacks in his body than attacks in his thick skull.
 * In Fullmetal Alchemist, Winry hits Ed on the head with a wrench, often, and he is usually shown collapsed on the ground, bleeding more than enough to be worrying. Strangely, always Played for Laughs, since he inevitably recovers.
 * The titular Inuyasha tends to get thrown through the terrain face-first a lot. Usually, the terrain gives up. In fact, he never responds to head injures, and the only damage he pays attention to is the kind that makes it harder to swing his BFS around.

Comics
"Hardhead: Hard. Head. It's not just a name, you know."
 * Notoriously, The Spirit. "Hand me that chair, Lorelei, this one's got a head like concrete...."
 * The horrid comic Rock Heads, MiSTed here.
 * The IDW Transformers comic series gets a groan-inducing Incredibly Lame Pun out of this when Hardhead gets shot in the face.


 * Spider-Man villain Hammerhead has an Adamantium plate embedded in his head. Of course that's not the entirety of his shtick -- he's a mobster movie fanboy, who dresses and acts like Al Capone and often uses a tommy gun.
 * In The Beano, it's a Running Gag that Smiffy of The Bash Street Kids is so thick that his head is indestructable.
 * Played with in one of Don Martin's paperback collections. One story tells of Fester Bestertester discovering that Karbunkle has "The Hardest Head In The World". The plot then becomes a parody of the typical movie rags-to-riches-to-rags-to-recovery story ... Karbunkle becomes a star, rich living makes him soft (literally, to where his skull can't even stand up to creamed spinach), his family forgives him, and he works his way back to success again.
 * Tintin, Tintin, Tintin. Barely a page went by without someone suffering a Tap On the Head, and they'd usually be back on their feet within five minutes, nursing the bump and watching the birdies circle.

Films -- Animation

 * In Castle in The Sky, after Pazu jumps off a wall, crashes through a brick floor, and lands on the floor, he give the page quote. He gets plenty other blows to the head throughout the movie.
 * In the original Japanese, he says something closer to: "My head is harder than my boss's fist."
 * In Final Fantasy VII: Advent Children, Rude has a thick metal billboard and its supporting structure fall on his head while he's busy fighting Loz. The billboard AND the structure bend/split in half where they connect. He's only momentarily stunned.
 * He also gets whacked upside the head by Reno's Nightstick -- which did send him stumbling, but he recovers remarkably fast.
 * Film/Nine: Even after 9 smacks him in the face with a monkey wrench (by accident, of course), 2 only needs to be helped back onto his feet and walks around, with seemingly no ill effects from the blow, despite the fact he's one of the older stitchpunks. Of course, his head gear might have absorbed a lot of the blow.
 * That and for all we know there isn't anything in his head that would be damaged by it.
 * Averted in a scene in the Pixar movie Up. Early in the movie in a moment of anger hits a man over the head with a metal object . The injured man makes cries of pain as he stumbles back with blood running from a gash on his head.
 * Another Pixar film, Toy Story 2, has Rex being used as an impromptu battering ram. Over his objections. An "outtake" shows them doing this, and failing.
 * Justified in that Rex is a toy and can probably take the punishment just fine.
 * In Tangled Flynn takes a frying pan to the head more than once with out any side effects.

Films -- Live Action
"Paul: (holding his head in pain) Nobody wins with a headbutt!"
 * The Three Stooges used this a lot. Curly in particular dulled and blunted axes, saws, and chisels galore.
 * In the Drew Barrymore movie The Boys in My Life, a guy manages to defeat a jock simply by making him hit his head and break his hand. Based On a True Story?
 * Well, your forehead is one of the thickest and hardest bones in your body, which is why you use it to headbutt things, so yes, you can probably make someone break their hand if you headbutt their fist. Depending on the other guy's strength it can probably still give you an injury, though.
 * In Ernest Rides Again, the eponymous Great Redneck Hope ends up shot in the head by a renegade nailgun while pretending to be Indiana Jones at a construction site. He removes his hat to reveal that all three nails bent on impact -- "I'm glad it was the hard end!" -- and later, when by cutting the top half of his cranium off with a surgical saw, Ernest's head turns out to be hard enough to blunt it.
 * Uncle Buck. John Candy's character survives a bowling ball falling from a tall closet shelf onto his skull.
 * In Back to The Future, Marty McFly gets KOed when he gets hit by a car belonging to his mom's family, whacking his head on the pavement in the process. There don't appear to be any direct long-term consequences, unless you count the risk of Critical Existence Failure from his mom falling for him. In the second film, Biff KOs him when he visits the clock-tower hotel and casino. Later, he is briefly KOed by a door when his earlier self opens it; this is probably less disabling than not getting hit by the door would have been. And these are probably not all the examples.
 * In one of the series' famous sets of parallel events, Marty is knocked out cold in each movie, followed each time by a scene of him recovering with Lorraine (in Part 3 it's Maggie) at his bedside. In Part 3 the concussion happens when his head hits a fencepost. Needless to say, Marty will need a CT-scan when he gets back to 1985.
 * In the 1992 boxing film Gladiator, Brian Dennehy claims that a punch to the top of the head will do more damage to the fist than the head in a bare-knuckle brawl. In his fight with the hero, he tilts his head forward before several punches so that the hero injures his hands on his skull.
 * This one very much IS Truth in Television. While the very top of the head is vulnerable, the frontal bone of the cranium is way tougher than the bones in the hand.
 * In Shaolin Soccer, the eldest of the Shaolin monks is "Iron Head", who has a seemingly impervious cranium. His abusive boss repeatedly breaks bottles over his head to chastise his poor performance, with no effect.
 * Handled somewhat more realistically in Paul Blart Mall Cop, when Paul headbutts a Mook:


 * Conspiracy Theory: Mel Gibson goes around knocking people out with blows to the head. A few hours later they are just fine.
 * In Home Alone 2, Marv gets hit by several bricks dropped by Kevin from three stories above, which normally should've killed him (but then again, so should a lot of the other traps).

Literature
"Though I walk through the valley of the shadow of trauma, I will fear no concussion."
 * Garrett WILL get knocked out at least once per novel.
 * Nancy Drew and her friends (and the Hardy Boys in their books) were knocked unconscious multiple times in every book. It apparently didn't cause any lasting damage: Nancy never lost her detecting touch.
 * Subverted in Sandy Mitchell's Ciaphas Cain novel Duty Calls. Cain suffers a realistic head injury, putting him out for three days and inspiring nausea and dizziness. Cain plays it up or down as suits him, causing other characters to remind him that such an injury is serious.
 * Played half straight in For the Emperor, where Jurgen takes a glancing hit to the head. He would have died if not for his thick skull. Other than that, it is played realistically.
 * Uhm, no mention of the Carapace armor helmet he was wearing at the time?
 * In William King's Warhammer 40000 novel Space Wolf, when Ragnor considers that injuries can be more severe than they look, he remembers stories of men who suffered a light blow to the head, fought through a battle -- and dropped dead.
 * Subverted and lampshaded in Dorothy L Sayers' Murder Must Advertise; Lord Peter Wimsey comments on how the hero in an in-universe piece of fiction lightly shrugs off all injuries, while Charles Parker has been incapacitated by one head injury.
 * Discworld, Maskerade: Nanny Ogg is hit over the head with a champagne bottle. It does stun her, but she recovers quite quickly because there is some Dwarf in the Ogg ancestry.
 * Earlier, in Witches Abroad, Nanny has a house land on her. Turns out her witch-hat is reinforced, and Nanny survives because all the hat had to do was bust through the rotton floorboards of the lowest floor.
 * Averted in Monstrous Regiment: the medically-trained Igorina very carefully taps a guard's head in the right spot to knock him out without badly injuring him. (It helps that he stands still to let her do it, wanting it to seem like he put up a fight against the title regiment.)
 * Also averted in "Night Watch", where Vimes stops his younger self from hitting someone on the head in a sneak attack due to him knowing the risk of it killing the man.
 * Kahlan, in Sword of Truth, becomes determined to sneak out of a palace at one point, and is very reluctant to hit any guard who might insist she stay inside for her own safety, as she knows that she could as easily kill them as knock them out.
 * In the two-part Doctor Who Eighth Doctor Adventures novel Interference, Sarah Jane lampshaded this, by pointing out the risk of severe damage, and asks an alien exactly how they manage to do it without inflicting said severe damage, every damn time.
 * In P.C. Hodgell's Chronicles of the Kencyrath, heroine Jame is hit over the head at least twice per book, and recovers just fine. However, she's not human, and is or a race with a powerful Healing Factor; furthermore, even with that, she suffers realistic concussion effects from the worse beatings (ones that a normal human would have died from).
 * Played straight in the works of German author Karl May, where a knockout blow to the head is practically the author avatar's signature move. (His nom de guerre in the fictional West is "Old Shatterhand" for a reason.) Very occasionally subverted when a suitably nasty villain dropped by this does not come to his senses anymore... but usually it works just fine, in line with his stated aversion to killing other human beings.
 * Occasionally, he hits his targets too lightly, and they wake up too soon, usually adding humor to an otherwise suspenseful scene. Or it could make it even more suspenseful, if he ends up being caught by the enemy.
 * Played with all over the place in The Belgariad. Garion has a habit of hitting his head on things to no long-term effect, which eventually becomes a Running Gag and is even Lampshaded by Belgarath. The heroes also knock out whole swathes of Mooks, who conveniently come to when it's necessary to interrogate them. It's averted in a few notable cases, however: King Korodullin gets brained at the battle of Thull Mardu and has difficulty hearing afterwards; later in The Malloreon, a Cherek assassin gets hit over the head with an axe and Polgara proclaims him incapable of being revived.
 * Averted in Susan Dexter's The Prince of Ill Luck. Leith, the eponymous unlucky prince, gets hit on the head twice during the course of the book; both times, it renders him so sick as to be incapacitated for several days following.
 * All of Susan Dexter's books seem to approach this one pretty well; in The Wind-Witch, Kellis is so incapacitated by a blow to the head that he is unable to escape his prison when his fellow pirates do, and remains sick and nearly crippled for the week that follows his release. Admittedly, he was also
 * In Otherland, a drinking game could be made from the number of times a scene transition occurs through one or more protagonists getting knocked out, then reviving later with no ill effects. They are Inside a Computer System, so it's all technically virtual, although Your Mind Makes It Real is in play and many characters do indeed die in Real Life from fatal injuries in the Grail Network.
 * Lampshaped in the The Dresden Files. The hero, Harry Dresden, tends to get very much beat up over the course of a book. He's been shot, bitten, had bones broken, intentionally wrecked, near explosions, tossed around by supernatural powerful creatures, burned, frozen, and almost dissected while he was still alive. Thanks to Functional Magic, he recovers from these -- slowly, but he still continues to heal (at a normal human rate), until a wound's traces have gone away. Despite his injuries (he comments there are phonebooks smaller than his medical file, when he sees a doctor struggle to lift it), Harry has never broken his skull. He says he thinks someone snuck in and did an adamantium bone-coating on his skull somehow.


 * In Robert E Howard's The Hour of the Dragon, Conan the Barbarian is dazed and has his vision blur after a head injury -- but that hardly stops him.
 * Subverted in Justin Cronin's The Passage. When Michael is said to have been unconscious for several days but has no slurring, unfocused eyes, or signs of a concussion, it tips off Sara, a nurse, that something isn't right.
 * Averted in the Gone series. In the second book, Hunter is knocked out by a crowbar to the head. When he wakes up, he can barely speak coherently, and even after receiving supernatural healing, he is left with permanent brain damage.
 * In The Wishsong of Shannara Garet Jax establishes himself as a Badass when he rescues Jair from a group of gnome warriors, killing them all with a Simple Staff. All but the leader of the group that is, when they're inspecting the bodies Jax notices that the leader is unconscious but still alive, and comments that the gnome must have a particularly thick skull.
 * Justified in Supernaturalist, when Cosmo has a metal plate implanted in his skull during surgery. It becomes a Chekhov's Gun later on when he needs to headbutt his way out of a containment vat.

Live Action TV
"Cordelia: How many times have you been knocked out, anyway? I swear, one of these times, you're gonna wake up in a coma."
 * In the episode of Happy Days where, Fonzie and the gang are trapped in the bathroom, and the Fonz gets the bright idea to open up a pathway by putting on his motorcycle helmet and bashing a hole in the wall. After crashing through the wall, he pulls his head out, and one of his friends asks what the wall was made out of because it broke so easily. The Fonz calmly replies "Concrete" and falls unconscious. Other than knocking himself out, he suffered no injuries from headbutting through a concrete wall.
 * Dexter: Dexter headbutts Doakes in the face and walks away apparently unaffected by the impact. The only effect on Doakes is to infuriate him into attacking Dexter -- in front of everyone else.
 * Then again, Dexter probably didn't ram Doakes very hard, as the point of the attack was to provoke and not to injure Doakes.
 * Although less extreme than many examples, Casey from Chuck seems to have a very hard head. He's fond of headbutts, and in one fight scene his opponent punched him in the forehead and clutched at his hand in pain, while Casey ignored it completely.
 * Buffy the Vampire Slayer
 * Giles has been KO'd by blows to the head many, many times. He never suffers any ill effects. He actually lampshades it in the game by suggesting he had built up a tolerance for cranial trauma.
 * Lampshaded by Cordelia in the episode Gingerbread:


 * Lost: Headbutting, Pistol Whipping, and other Taps on the Head are (usually) of no consequence. For instance, in the season 5 finale, Jack is hit with, but gets up moments later. May be justified in that the island has healing powers and won't let people die if their destinies are not yet fulfilled.
 * Vyvyan of The Young Ones who, in one episode, strikes oil by cracking the basement floor with his head, later helps dig it out by headbutting the hole (which leads to Neil accidentally putting a pickaxe through his head), and, from his first appearance, has metal studs on his forehead.
 * In Smallville, Lex and Lana tend to get knocked unconscious about once an episode.
 * Forever Knight. When the vampire protagonist-turned-cop is shot in the head he naturally regenerates, and his friends have to scramble to cover things up. LaCroix steals the X-Ray and hypnotises the doctor into saying that the bullet merely glanced off the protagonist's "exceptionally thick" skull.
 * In Scrubs, Dr. Kelso apparently has a "head like a mountain goat", as evidenced by an occasion where the Janitor hit him over the head with his mop and it "only made him mad".
 * Doc West trains three guys for a fight match, making them focusing on their stronger point: kicks for one, Berserk Button for another, and Hard Head for the third. This last is trained to get punched in the face for several minutes, without countering or dodging on purpose, to tire the opponent. It works.
 * Avon of Blakes Seven was knocked out an impressive number of times through the series, apparently without damaging his IQ (although he did go slightly off the edge in the last season).
 * Averted in Mighty Morphin Power Rangers: Kimberly, while practicing after being exhausted by a battle, falls off the balance beam and hits her head. She suffers a concussion and has to be put in the hospital.
 * Prince Arthur on Merlin. Repeatedly. Like, every time Merlin has to do a spell in front of him, he's conveniently knocked out.
 * Morgana as well. Between the two of them, it's not wonder the show can run on Idiot Plots.

Pro Wrestling

 * Generally considered a trait of all Samoans, whether they are Wild Samoans or not.
 * WWE's Vladimir Kozlov often uses his head as a battering ram to devastating effect on his opponent and no ill effect on him.
 * The Missing Link also famously used his head as a weapon.
 * Japanese indy wrestler Keni'chiro Arai has a head so hard that hitting him over the head with a chair revitalizes him.
 * The Bushwhackers had heads so hard, their Battering Ram finishing move involved one grabbing the head of the other and running it into their opponent.
 * Bad News Brown often simply got angry when his head was slammed into a turnbuckle.
 * Averted by Al Madril of Pacific Northwest Wrestling: he was known to lose matches when he attempted to head-butt his opponent and then fell back unconscious.
 * Tragically averted in the case of Chris Benoit. Benoit was known for his Diving Headbutt finisher, but using it so often throughout his career contributed to the massive number of concussions he suffered, resulting in brain damage and one of the factors in his ultimate fate.

Tabletop Games

 * Averted in GURPS. Blows to the head do quadruple damage, have a good chance of causing unconsciousness and the "critical head blow" table is pretty nasty.

Toys

 * Nearly all characters in Bionicle- Justified due to their being heavily armoured cyborgs with Artificial Intelligence. Hitting one of them in the head tends to knock them out with no adverse side effects.
 * Hewkii, in particular, has been known to smash rocks with his head- for fun.

Video Games

 * Bully: Jimmy Hopkins can take a bat to the head ,yet he can't stay up past 2 AM.
 * Subverted in the game Godzilla: Unleashed. Whenever a monster (Godzilla, Rodan, King Ghidorah, etc.) runs headfirst into another monster (especially a Giant Mecha like Mechagodzilla or M.O.G.U.E.R.A), the first monster ends up stepping back and shaking its head as if in a daze.
 * This is also played straight with Mecha-King Ghidorah, whose "victory pose" consists of him slamming his mechanical center-head into his flesh-and-blood side heads (which must be the three-headed dragon version of a "high five"). Don't ask how this doesn't cause the side-heads to end up with broken jaws or whatnot.
 * Because we're talking about a 500-foot tall lightning-spewing, nigh invulnerable, cyborg dragon.
 * Mario (as well as Luigi) can break blocks made of brick with his head. Heck, he can sometimes hit the exact same brick several times in a row without showing any signs of headache or loss of brain cells. Of course, we are talking about an overweight plumber who can jump unnaturally high, is rivals with a giant fire-breathing turtle, and can fit into a drain pipe.
 * In most of the games, he holds up a fist and hits the blocks with it, instead. Which then poses the question: why doesn't his fist get really sore? He's wearing gloves, of course. Also, don't forget that he grows taller by eating mushrooms, shoots fire out said fist by eating flowers, and becomes a raccoon by eating leaves. And he gets hurt more if his hat falls off. Basically, everything is justified, because nothing is.
 * Though despite his iron hat or whatever gives Mario his freakish bone density, he was still knocked out cold by a cave ceiling he springboarded into in Super Mario RPG.
 * Mario's methods are lampshaded in a Howard & Nester Super Mario Bros 3 comic, where Nester tries to break a floating block by hitting it with his head... and knocks himself out. Howard helpfully points out that he should try hitting it with his fist instead...
 * Averted by (of all things) Baldurs Gate. Minsc took a blow to the head in the defense of his witch Dynaheir, and ended up a little... off as a result. Permanently.
 * The first recruitable units in Brutal Legend were once enslaved miners, forced to break rocks with their heads instead of proper tools. Freed from the mine, they now use their heads for ramming attacks in battle. (It's a setting that runs on The Power of Rock, so they're referred to as "headbangers.")
 * The first, and eighth, Mega Man X game justified this by giving X a reinforced helmet upgrade.
 * X being a robot likely has a little something to do with why that doesn't hurt him.
 * In the first and second Fallout games, scoring a critical hit with an aimed attack to the head may cause stunning, unconsciousness for several rounds, or death. If you're the recipient of the second and manage to wake up before your foes kill you off completely, you will have suffered no obvious loss from the trauma, other than hit points.
 * Jagged Alliance 2: Attacks to the head may cause reduction in the wisdom attribute. Also, death.
 * In Dwarf Fortress, a headshot can K.O. a creature. It's difficult to say whether dwarves can suffer permanent head trauma, since they act no more or less retarded than before.
 * Creatures with permanently injured brains do fall unconscious more frequently (and for less reason) than their healthy peers, though.
 * A Pokémon with the ability "Rock Head" will not take recoil damage from its own attacks. Quite useful, as attacks that cause recoil damage tend to be very powerful.
 * Link in the 3-D Zelda games will often ram into walls with his head while performing an Unnecessary Combat Roll. He is never harmed in any way by this, despite taking damage from falls and some other impacts. Perhaps his doing that so often made him mute?
 * Eric from The Lost Vikings smashes through the walls with his head on a regular basis.
 * Played straight in Batman Arkham Asylum and Batman Arkham City, where Batman, being against killing, gets rid of the thugs by combat, which consist in many kinds of strikes, some ones on the head, and takedowns, which includes bone breaking and hitting heads against the floor, letting the enemies like "unconcsious", but being absolutley still in the floor, just breathing and with a blood pressure half the normal. Also we had to consider Batman had so much medical skills, so, he would must be aware of the fatal effects of the hits on the head.
 * Possibly played straight in World of Warcraft: Cataclysm. A quest in Vasj'ir has the player relive a naga's memories of fighting kvaldir. The memory starts off with a naga remarking that "The skulls of these kvaldir are hard as rock!" since the player controlled naga had apparently just broken her trident over a kvaldir's head. Since this event is off-camera whether or not the kvaldir survived the blow to the head isn't known, but naga throughout the memories only kill kvaldir with torso-targeted attacks.

Web Comics

 * Played with in Girl Genius. After Oggie knocks Lars unconscious, the next scene starts with Lars awakening in a bed with Oggie assigned to watch over him to make sure he was OK. After confirming this, Oggie excitedly informs another character of it: "See? He's avake und talking und no more schtupid den he vos before!"
 * Oggie is in the position to give professional opinions on stupidity, judging by the fact that he told Lars he was knocked out by a brick from the bridge that exploded shortly before he was knocked out. He attempted to prove it by showing him a brick with a confession note (reading "I HITT MR LARZ (SYNED) A BRIK") written on it.
 * Justified in that Oggie is a Jaeger. When a genetically engineered monstrous featured super soldier offers you an obvious lie as part of an overture of friendship, it's generally considered a smart idea to accept it.
 * In Dominic Deegan: "I break things with my face."
 * The Adventures of Dr. McNinja plays with this one. In most instances a character who takes a wallop to the head (or a chop to the neck) comes out fine. However, the back of Doc's head was once rudely introduced to a piece of wood (pirates and alcohol were involved) resulting in a concussion and a hallucinatory conversation with a roast turkey. (He got better.)
 * Dan from Dan and Mabs Furry Adventures has such a hard head that he actually has to ask if another character tried to knock him out.
 * "Gnnngh! It was like hitting a solid rock!"
 * In Eight Bit Theater, Fighter is a master of the ram technique of Zodiac Kenshido, which consists of breaking your opponent's equipment with your head before he breaks your head with his equipment. He also gets stabbed a lot, and once broke through the Armoire of Invincibility with his head (However, it was just the cheap, particle board base, but it still should have been invincible particle board). In some cases, getting hit/stabbed/shot in the head has made Fighter smarter.
 * Very much Deconstructed in this VG Cats comic.
 * Shelly of Wapsi Square turns out fine after taking a bowling ball to the head. However, the injury is treated as potentially serious, and she is taken to the hospital. The doctors find nothing unusual save for an abnormally thick skull.
 * Lieutenant Der Trihs in Schlock Mercenary literally has an artificial skull made of carbonan (a diamond-like carbon material). A doctor comments that in his case, this is like "keeping potato chips in a safe-deposit box".
 * El Goonish Shive: Elliot is whacked when found by a guard in the 'Sister' arc. Wrong Genre Savvy, perhaps? When he comes to, he's worried about concussions, brain damage, et cetera. Tedd brushes him off and gets on with some exposition.
 * Precocious: You must have a pretty hard head
 * In Endstone, Cole seems unfazed by a serious blow to the head, and Herrik comments on it.
 * Played half-straight in Yosh!, where the first thing Phil does after knocking out a witch is check that he didn't kill her (she's alright).
 * In Order of the Stick, Durkon gets a lump on his head. His only reaction is to feign memory problems, to lack a spell to cast on Belkar.
 * Mora from Las Lindas. Bludgeoned in the back of the head with a shotgun? Bludgeoned so hard the shotgun breaks in two!? Feh. Just a minor annoyance.

Web Original

 * Parodied in The Gamers. The characters try to knock their friend unconscious, so his "paralysing fear of water" won't get in the way as they cross a shallow river. They try a few times, in vain, with him losing health points every time, till eventually, one character lands in such a strong hit, that he is "very unconscious". But unfortunately, as the player counts the hit points his character lost, it also turns out he is dead. The blow killed him.
 * Subverted in Survival of the Fittest in the case of Sean O'Cann. Upon his introduction to the game, Sean is already suffering from a head wound as a result of landing on something hard after being thrown onto the island. After this wound is bandaged, it's seemingly forgotten... up until a couple of days later, when Sean really starts to suffer, his vision blurring frequently and he himself collapsing on more than one occasion.
 * Averted in the v4 Pregame when Christopher Carlson gets the crap beaten out of him by Monty Pondsworth at lunch; he's stated to have spent a good week with a headache and spent the rest of the day having trouble walking.

Western Animation

 * Practically a defining trait. Bugs Bunny, Daffy Duck, Wile E. Coyote, Tom and Jerry -- etc.
 * In the Transformers Generation 1 episode "Call of the Primitives", Autobots and Decepticons are united against a common foe. Druing the battle, the massive Trypticon lands on Grimlock and he is presumed dead. Much later, after the battlefield was abandoned, Grimlock, still alive, manages to blast his way out from under him. Upon freeing himself, he quips, "Good thing me Grimlock have hard head. Otherwise would now be Dino-splatter!"
 * Brought up in The Simpsons, where an episode reveals that Homer has thick layer of fluid between his skull and brain that give him enormous resistance to cranial damage. Known as 'Homer Simpson Sydrome' Homer: "Oh, why me?!"
 * Subverted humorously in Beast Wars, where Blackarachnia falls unconscious shortly after knocking out Silverbolt with a headbutt, and feeling rather stupid about trying it in the first place. Even though this is the one series where you might get away with ignoring the KO considering that they're Mechanical Lifeforms.
 * In Code Lyoko, the kids get smashed in the head all the time, but it doesn't seem to have much effect on their fighting. The frequent Returns to the Past certainly help staving off any long-lasting effects.
 * While he unsurprisingly has yet to be knocked out by a blow to the head, Hammerhead from The Spectacular Spider-Man has used his to smash through brick walls without ill effects.
 * Well, he's not called Hammerhead for stubbornness; he has a metal plate implanted in his skull.
 * In Wakfu, a Hard Head seems to be one definite trait of Iops. Sadlygrove Not that the other heroes are slouch either, and regularly receive some serious beating with barely a trace a few frames later.
 * Lampshaded in Archer: When the title character knocks out a colleague in order to take his place on a mission, he advises, "Try not to stay unconscious too long. It's like, super bad for you."
 * Others later comment on how he could have serious head injuries and he agrees about that and already has a medical appointment to make sure there's no permanent damage.
 * Zuko from Avatar: the Last Airbender most definitely counts. Possibly subverted by the fandom, in that least one youtube video shows clips of Zuko's extensive and varied head injuries as an explanation for his behavior in the second season finale: http://www.youtube.com/watch?v=K Hm E 1 ZW Lxv 0

Real Life

 * Truth in Television for certain animals -- such as bighorn sheep -- but emphatically not so for humans. If something knocks you unconscious, seek medical attention immediately.
 * How are we supposed to do that if we're unconscious?
 * Call the paramedics beforehand.
 * This would, of course, be why humans engaging in hazardous activities often wear helmets. Even with a helmet on, a hard enough blow to the head (or being too close to something exploding) can still cause brain damage.
 * There are masters of the Iron Head kung fu technique who can break things with their heads. Don't Try This At Home, folks. Not even with stacks of Polo mints.
 * To achieve this, the skull must suffer microfractures. The healing process thickens the skull a bit. Then you repeat the process. Ouch.
 * Most objects used in breaking demonstrations tend to have a 'sweet spot' where fracture can be induced with significantly less force (and hence less trauma). For practitioners who exploit this fact the stunt becomes as much an artful display of precision as it is a show of this trope.
 * Subverted with the dinosaur Pachycephalosaurus. It was once believed that this dinosaur did use its dome-shaped head to ram into one another's heads (much like modern-day bighorn sheep). However, recent fossil evidence indicates that this was not the case and, instead, Pachycephalosaurus tended to fight for mates/territory by using their dome-shaped heads to ram one another in the stomach, thighs, or legs (Much like what you'd see in modern-day giraffes).
 * The NFL has had to change its rules, due to recent research into head injuries. The discovery of a previously-unknown type of dementia common among retired NFL players has resulted in an unpopular increase in player fines for unnecessary roughness, and has changed the standards for players to be allowed to return to the field after a head injury. Research suggests that the time it takes to recover from a concussion is actually unknown, but may take weeks or months; and repeated concussions during that period may lead to dementia. Football culture has traditionally valued the ability to play through this type of injury; former Chicago Bears safety Doug Plank, for whom the "46" defense is named, used to speak of playing while so disoriented that he had to be guided to the correct sideline when leaving the field.
 * The NHL is also beginning to acknowledge this, especially after several players like Derek Boogaard whose primary role was to fight guys like that on other teams and consequently took a lot of blows to the head died relatively young and were found to have serious brain damage post mortem.
 * Very rarely this is played straight in real life, and a human being will have a biological oddity that grants them a minor version of this. For example, CT scans discovered that boxer Julio Cesar Chavez Sr. had a skull that was considerably thicker than normal, which perhaps explains why Chavez was able to fight for many years and in so many slugfests while seldom being affected by his opponent's punches. Other examples exist as well, some with medical justification, such as "Marvelous" Marvin Hagler, (apparently the muscles surrounding Hagler's head are several times thicker than normal and created a cushioning effect) Jake LaMotta, (whom the movie Raging Bull is based on) and George Chuvalo.