In some traditions, the sword is ascribed no powers of its own. It is famous because it is the hero's sword, or because of its origin, as when a god gives it to the hero. Other swords keep their wielders safe or destroy their enemies. A more localized motif is the sword that has been broken and must be reforged, commonly found in Northern Europe. Such a sword symbolizes the initial defeat and loss of honor of its wielder. Subsequent victory and the restoration of honor is achieved by reforging it, either at the wielder's hand or that of his heir.
It is probable that the roots of the sentient weapon myths stem from ancient peoples belief that sword making and metallurgy was in fact a magical process. Through the fires of the forge (fire was also given spiritual connotations) a lump of earth was transformed into a shiny usable object that could be hammered into many shapes. Extending further from the transformation of ore into metal, the difficulty of actually obtaining a quality blade; which took intense concentration and skill added to its esoteric qualities. While any blacksmith could manufacture a knife or an axehead only a swordsmith could create a high quality sword. The secrets of doing so were jealously guarded as well as formulas for alloys.
The skill necessary to forge a balanced blade - one which is not too brittle or too soft and able to hold a usefully sharp edge - in the age before automated machines, blast furnaces, and the knowledge of molecular chemistry made the creation of a sword seem almost miraculous. A few degrees too hot or too cold within a very limited temperature range, which could only be discerned by the glowing hue of a hot billet, could make or break a sword. A lack of expertise in knowing when and how to apply carbon and flux and quench the blade could ruin weeks of work. Thus the swordsmith almost felt like he was one with his work, giving the process his complete devotion of concentration and thought. This led to the belief that he was actually imbuing the blade with an essence of his spirit. In Japan, the swordsmiths were so concerned with this belief that they would undergo purification rituals and meditation before even attempting to start a new blade, for fear that they might inadvertently create an evil sword.
The Vikings prized their swords above all other things, handing them down from generation to generation and giving them names. The value of the blade was not only determined by its quality but also by how many battles that it was used in. Polynesian people such as the Māori also had comparable reverence for their weapons. They believed a weapon contained a spiritual force called mana and that the weapon held the spirits of its maker, its line of owners and also stole the spirits of those it killed. These weapons where highly prized for their mana and cherished as heirlooms. The Samurai of Japan believed that their swords had their own soul that could possess them. It was not the wielder but their swords that desired to kill; Samurai were just the instrument that the sword used to complete that task. Since most of them were Buddhists (a religion that finds violence and murder abhorent), that train of thought gave them some peace of mind in their killing vocation.
Later, as the concept of demons, spiritual possession, and elementals entered the realm of mythological themes, it was only a natural leap to attribute magical properties of the swords of folklore to indwelling spirits.
Magic swords may exhibit various degrees of sentience, from being merely influenced by the wielder to being able to think for itself or even control its owner.
The Bible relates in the Book of Genesis how God, seeking to deter Adam and Eve from returning to the Garden of Eden, "placed at the east of the garden of Eden Cherubim and a flaming sword which turned every way". By some accounts, the Cherubim are replaced with the Archangel Michael, who wields a similar weapon. King David was given the sword of the slain giant Goliath by the priest Ahimelech, to which was attached extra-biblical mythology and traditions. In the Book of Revelation, Jesus is symbolically described wielding a double-edged sword that proceeds out from his mouth, in reference to the "sword of the spirit" which is the "word of truth".
In the legend of King Arthur, the king himself is related to two magical swords, in most variants. The first is the Sword In the Stone. Only Arthur could draw it out, thereby proving that he is the rightful king. In some tales, this is his only sword. In most variants, this sword was then broken, and he receives from The Lady of the Lake a new sword called Excalibur, arguably the most famous of magic swords. Caliburn was the original name of Excalibur. In Welsh legend, Arthur's sword is known as Caledfwlch.
Geoffrey of Monmouth's History of the Kings of Britain is the first non-Welsh source to speak of the sword. Geoffrey says the sword was forged in Avalon and Latinises the name "Caledfwlch" as Caliburnus. When his influential pseudo-history made it to Continental Europe, writers altered the name further until it finally took on the popular form Excalibur. However, in other variants Excalibur itself is the sword in the stone. It is not clear from the various accounts of the Arthur legend whether Excalibur itself was possessed of magical powers or merely had a magical origin, though its scabbard protected its bearer from physical harm. Many interpretations of the legend appear to endow Excalibur with a cutting strength and durability beyond that of ordinary weapons.
In Wolfram Von Echenbach's Parzival, the eponymous hero is given a sword by the Grail king, Anfortas. Parzival's cousin explains that "“The sword will withstand the first blow unscathed; at the second it will shatter. If you then take it back to the spring, it will become whole again from the flow of the water. You must have the water at the source…If the pieces are not lost and you fit them together properly, as soon as the spring water wets them, the sword will become whole again, the joinings and edges stronger than before.”
Tyrfing appears in the Hervarar Saga. Svafrlami was the King of Gardariki, and a grandson of the god Odin. He caught the dwarves, Dvalin and Durin, and forced them to forge a sword with a golden hilt that would never miss a stroke, would never rust and would cut through stone and iron as easily as through clothes. The dwarves made the sword, and it shone and gleamed like fire. However, in revenge they cursed it so that it would kill a man every time it was used and that it would be the cause of three great evils. They also cursed it so that it would kill Svafrlami himself. It would cost the life of not only Svafrlami, but also the life of the Swedish hero Hjalmar.
A similar sword to Tyrfing is Dáinsleif, a sword from the legend of the eternal battle Hjaðningavíg, made by the dwarf Dáin. Like Tyrfing, Dainsleif gave wounds that never healed and could not be unsheathed without killing a man. There is also Mistilteinn, a sword from the Hrómundar saga Gripssonar, which could never go blunt and which Hrómund won from the undead witch-king Þrainn. Like Tyrfing, it was taken from a barrow-wight.
The various iterations of the story of the Völsungs include several magic swords. The first magical sword which enters the story is Gram (="wrath"), stuck by Odin into the tree Barnstokkr in the hall of the Völsungs. Only Sigmund could pull it out. This caused considerable envy and conflict. Eventually, Sigmund fought Odin disguised as an old man, and Odin shattered the sword. Sigmund left it for his son Sigurd, who reforged it to kill Fafnir. In the Nibelungenlied, Sîfrit (the Middle High German version of "Siegfried," the equivalent to Norse Sigurd) discarded Gram in exchange for another magic sword, Balmung (= "destruction"). Wagner's version of the story calls the sword Nothung ("child of necessity/distress"), rather than Balmung.
Beowulf wielded the sword Hrunting that was according to the poem annealed in venom. The sword was useless against Grendel's Mother. In desperation Beowulf grabbed a giant sword of great age and with it took off the head of the she monster.
In Japanese mythology, there is a magical sword called Kusanagi, which was one of the three crown jewels given to the Emperor Jimmu by the goddess Amaterasu. Additionally, the katana forged by Masamune and Muramasa were reputedly of such high quality as to be near-magical. In the case of the Masamune and Muramasa blades, it was believed that some element of the smith's personality was imputed into the blade. These three swords have been used extensively in popular culture since then, especially in the realm of video game RPGs. Despite legends about Nihontō, those three are the most famous. Excellent Japanese swords often received nicknames reflecting their cutting prowess. Also, unlike other magical swords, they exist (or still exist). There is, for example, 10 or 11 blades attributed to Masamune who still exist today, such as Kanze Masamune, Kotegiri Masamune or Musashi Masamune.
In Spanish legends, two magic swords belonged to the warrior Rodrigo Díaz de Vivar, "El Cid", according to the medieval epical poem "Cantar del mio Cid". The first, "Tizona", had a personality of its own, and its strength varied according to the person who used it. "Colada", too, had power only in the hands of a brave warrior.
In the Matter of France, Roland possessed an indestructible sword, Durendal, which he threw into a poisoned stream to prevent its capture. Durendal was one of a set of three swords supposedly forged by Wayland and provided as ransom for a Norse captive, the other two being variously Bishop Turpin's sword Almace, Charlemagne's Joyeuse, or Ogier's sword Curtana.
Edmund Spenser's The Faerie Queene features a golden sword called Chrysaor, the personal weapon of Sir Artegal, the Knight of Justice. The sword was given to him by Astræa, who had been holding it since the days when Zeus had used it to battle the Titans. Because it was "Tempred [ sic ] with Adamant", it was described as being able to cleave through anything.
In Der Ring des Nibelungen, Richard Wagner drew on the legends of Grimm for the sword Nothung, belonging to the hero Siegmund and later reforged by his son Siegfried and used by him to kill Fafner. It is finally used by Siegfried to shatter the spear of his grandfather, the God Wotan, thus ending his power.
The hero of Lewis Carroll's poem "Jabberwocky" slays the Jabberwock with a vorpal sword. Although the poem does not define the word "vorpal" (and contains many nonsensical words with no meaning), the term has been adopted in role playing games to describe a sword which possesses a magical ability to decapitate those against whom it is wielded.
In the works of J. R. R. Tolkien such as The Lord of the Rings, many magical swords, usually with powers for good, are wielded by important characters. Gandalf uses his sword Glamdring in his battle with the Balrog, which wields its own sword of flame. Glamdring's sister blade, Orcrist, is buried with Thorin Oakenshield under the Lonely Mountain in The Hobbit. Bilbo, Frodo and Samwise carry the sword Sting. It and Glamdring both glow blue when orcs are near. Aragorn bears the sword Andúril, a potent weapon against the evil of Mordor and a symbol of his right to rule. Turin Turambar, the main character of The Children of Húrin, wields the sword Gurthang. He eventually kills himself using the sword, which speaks to him before he dies, telling him it will kill him. This story is based on the Finnish hero Kullervo, whose sword also agreed to kill him. In addition, in Farmer Giles of Ham, the protagonist is given and wields a magic sword named Caudimordax which, in the story, is translated to mean "Tailbiter".
In Margaret Weis and Tracy Hickman's Darksword series the Darksword is a sword capable of absorbing magic.
Michael Moorcock created a sinister magic sword in Stormbringer, wielded by Elric of Melniboné. This black sword has the power to suck out the souls of its victims and transfer their energy to its holder. It also appears to have a mind of its own, sometimes striking against its "master's" will. Mercedes Lackey's creation, the sword Need is similarly independent, although along less sinister lines.
Lawrence Watt-Evans's The Misenchanted Sword (1985) involves the difficulties of dealing with the sword of the title; the protagonist must kill a man when he draws it, can only kill one, will die if he ever kills a hundred men with it – and will not die without killing them, but will ceaselessly age.
The Blue Sword contains a blue sword, known as Gonturan, that is both a symbol of power (as it can only be used by a damalur-sol, a woman hero), an amplifier of magic and a very sharp sword. It is also a sword with a mind of its own.
In Robert Jordan's The Wheel of Time is the sword Callandor, which is actually not a sword, but a powerful Sa'angreal shaped as a sword and made out of crystal. It is kept within the Stone of Tear. It can only be taken by the Dragon and is a major sign of his return. Until he takes it the Stone of Tear will never fall to any invaders, but when the sword is taken the Stone is said to fall to the People of the Dragon. It is later revealed that unlike other Sa'angreals it does not have the safety mechanism that prevents a wielder from absorbing too much of the One Power through it.
Terry Goodkind's series is named for its magical weapon, the Sword of Truth. This blade, with the word "Truth" inlaid into the handle, factors into many of the moral decisions made by Richard Rahl, the series' protagonist. The blade, like most magic in the series, is focused on need. The sword's master is referred to as the Seeker of Truth. The Seeker gains the swordmastery of all those that have wielded the blade previously. Many false Seekers have carried the sword, but a true Seeker can only be named by the First Wizard (Rahl is named by his grandfather, Zeddicus Zorander). A true Seeker has the ability to turn the blade white when he kills in compassion and forgiveness. Richard has done this twice. Once, killing the Mord-Sith which captured him in Wizard's First Rule, and again to kill a Sister of the Dark in Stone of Tears.
The eponymous sword from The Sword of Shannara series, by Terry Brooks, has a distinctive pommel in the form of the druidic symbol from the series: a hand holding aloft a torch (similar to the Statue of Liberty). Otherwise it is visually unremarkable, though very well made and unworn. Its ability lies in revealing absolute truth, which can be difficult to bear. The sentiment of the enchantment follows that of the "To thine own self be true..." advice to Laertes. A prospective wielder, upon drawing the blade for the first time, is made to confront all their personal flaws, shortcomings, fears, delusions and morally questionable acts. If the being's psyche cannot deal with the revelations, they might not be permanently harmed, but the blade is unusable to them. However, if they can accept the truth of themselves, though it is still a jarring experience, they come out of it wiser for the self-knowledge. Also, they are able to wield the Sword as both a particularly strong and sharp weapon, and as a harsh mirror of Truth to those touched by the blade. This exposure to reality, like many years of counseling condensed into a moment, can actually destroy anyone "evil" enough, e.g. the Warlock Lord of the same book. It also can reveal illusions and give some protection from magical effects.
Also of note is the Sword Nightblood from the book Warbreaker. Nightblood is a sentient sword which was given a direction when awakened. This direction was to 'destroy evil.' However, being a sword, Nightblood could not judge right and wrong and killed almost indiscriminately. Simply undoing the clasp (which was extraordinarily tempting for one without a pure heart) was enough for nightblood to utterly destroy the one holding it. Nightblood was often recovered by Vasher sticking clean through a man, not even unsheathed. Nightblood, when fully drawn consumed Its user's BioChromatic breaths at an alarming rate, while sending tendrils of darkness out to destroy anything the sword deemed 'evil.' The sword could also telepathically communicate with its wielder, often asking questions such as "Hello, would you like to kill someone today?" or alternatively asking to be unsheathed.
The Harry Potter series of novels by J.K. Rowling features the Sword of Gryffindor, which is used by several of the book's prominent characters. The sword is an indestructible weapon crafted from goblin metal, the properties of which allow the sword to absorb any substance into itself that will make it stronger, in the case of the books, the immensely deadly venom of a basilisk.
In series: The Dancing Gods, by Jack L. Chalker, the protagonist, the barbarian Joe, is given "The last unnamed magical sword in Husaquahr". In order for the sword to bond with Joe, he has to give it a name, preferably something heroic. However Joe names the sword "Irving" after his son. In response to the exclamations concerning his choice of name, he states "...but I like the name Irving". Once bonded, the sword will fight for no other user, and will return to Joe if he calls it.
The Sword of Baldanders is among the swords featured in Akita Yoshinobu's Sorcerous Stabber Orphen series. being used for transforming a Killing Doll into a humanlike body, transformations of males into females and transformations of humans into beasts.
Movies and television across varying genres depict swords with magical qualities.
Video games and fantasy role-playing games feature a great variety of magical armaments, most commonly represented by swords and similar archetypal weapons. These swords are rarely unique, and in many role-playing scenarios, magical weapons are so ubiquitous that the player characters are expected to come into possession of them as a matter of course.