How hard is the human skull really?

In some tv series recently, like Spartacus and The Walking Dead, people are frequently impaled through their heads in one go, like so

Is this possible, are our skulls really not as tough as we think? Assuming a realistic, good quality and well sharpened sword.

Another thing you see sometimes is a katana user slicing off clean a part of the skull. Is that possible?

A related question: would someone die instantly from a cut like the one in the screenshot?

Ask all the people that have hit one if they are hard…Yes they are very hard. Hard enough to break boards and bricks and fingers. I thought they were at least partially rotted in the Walking dead to make it easier to jab through one.

yeah but the ones in spartacus aren’t. A related question, how difficult is it to completely sever a person’s neck with a single blow? Which also frequently happens.

Not too hard, considering it was a popular means of execution. Although it’d obviously be easier if you hit between the vertebrae, the big axes used would probably go through a vertebra without too much trouble; lots of momentum.

But what about a sword? Assuming a person who is standing instead of on his knees, allowing the executioner to put his entire weight into it.

Most of the skull is pretty hard, but the temporal bones (where your temples are) can be fairly easily penetrated if hit hard. I don’t know about a katana slicing a part of the skull off, but you could certainly embed one in a person’s skull (they used to test them on people; the best swords could cut a person in half at the pelvis, which is also very hard bone). Axes could be easily penetrate the skull, too.

This report and the accompanying x-rays indicate that yes, it is possible for one human to plunge a knife into the skull of another in one blow. A larger, heavier object such as a sword should be able to do the same, if not actually take off a piece of the skull.

I’ve seen some forensic photos showing human skulls with slices taken off, usually at the temples or upper part, or the upper part of the sides where the bone is relatively thin (but still hard enough to hurt if you, say, punched it with your fist).

Survival is a crapshoot even with modern medicine. It’s possible in the pre-medical past some survived penetrating skull injuries but it was probably unusual and a lot would depend on what, exactly was damaged/severed and how well the person was able to fight off infection.

As for severing the head at one blow - in recent years there have been some actual beheadings distributed on the internet. If you’re really interested I’m sure you could find them with a little effort.

The curved shaped of the skull allows it stand up to consider blunt force without fracturing, but a pointed or edged weapon can break through the bone more easily. Unfortunately for football players, too many blunt force impacts will damage the brain even if the skull is intact.

Need answer fast?

Looks like a case of that movie trope that is sometimes called, “Made of Plasticine.”

Warning: TVTropes link.

Wasn’t one problem of ancient warfare getting your sword/axe/misc. edged weapon stuck inside the poor guy you just killed and trying to get it out before someone did the same to you?

Lancers used to have cloth hanging off the end of the spear to make it easier to pull out. I don’t know if it works when it goes into the skull.

The preface of the penguin edition of Egil’s Saga claims that a couple of hundred years after his death Egil Skallagrimson’s skull was dug up and found to be unusually thick, and one of the workmen tried to smash it with an axe and failed.

Can’t find pics online for now, but Iron Age and Medieval battlefield excavations sometimes yield well-preserved human remains with clear evidence of what edged weapons can do to human bone. Stuff like forearms sliced clean off mid-bone with a single swipe of a sword, like a celery stalk with a Japanese kitchen knife. There’s much more bone to cut through in a forearm than in taking a slice off a human skull. Haven’t personally seen the latter injury, although deep gashes and depressions in skulls are a common sight in the archaeological material.

Ig Noble Price 2009:

PEACE PRIZE: Stephan Bolliger, Steffen Ross, Lars Oesterhelweg, Michael Thali and Beat Kneubuehl of the University of Bern, Switzerland, for determining — by experiment — whether it is better to be smashed over the head with a full bottle of beer or with an empty bottle.
REFERENCE: “Are Full or Empty Beer Bottles Sturdier and Does Their Fracture-Threshold Suffice to Break the Human Skull?” Stephan A. Bolliger, Steffen Ross, Lars Oesterhelweg, Michael J. Thali and Beat P. Kneubuehl, Journal of Forensic and Legal Medicine, vol. 16, no. 3, April 2009, pp. 138-42. DOI:10.1016/j.jflm.2008.07.013.

I can’t find any internet cites for this, but I’ve read that the execution of Anne Boleyn was outsourced to a French executioner who demonstrated his skills by beheading two condemned prisoners, seated back to back, with a single swipe of his sword.

Well, what was the winner? Need to know fast.


No, really. The bones of the body, including the skull, typically have an organic marrow enclosed by an inorgaanic matrix. That matrix is composed of apatite, CaPO[sub]3[/sub], the type mineral for level 5 of the Mohs hardness scale.

There is a difference, though, between hardness and toughness. A diamond is the hardest mineral on the Mohs scale but if you hit it right, you can easily turn it into dust and shards, because it’s REALLY brittle.

Decapitation by sword certainly happened, and expert swordsmen using high-priced steel swords could do it routinely … but your average person using tools they could scrounge (wood axes, cleavers, and the like) would find it very difficult indeed, at least in a single blow. Even expert executioners sometimes botched the job and had to more or less mangle the victim’s head off.

This is especially true of living bone. We don’t think of bones being flexible, but part of the reason a living/fresh femur can support such a huge amount of weight is the way it deforms under pressure. I saw a demonstration of a pressure test on a fresh femur on some TV show that was pretty impressive, but can’t find it online. I can find this page with a mathematical calculation that half the force needed to break a femur is still enough to compress it by 2 mm.

And I think this relates directly to the OP’s question. Small differences in the attack (power, angle, location, blade sharpness, etc.) could have dramatically different outcomes - if you can break the bone, you have a nice clean cut, but otherwise, you end up with some kind of elastic deformation that only produces an ugly wound. History says that a clean cut is not very repeatable even under controlled circumstances like an execution.