For war requires jousting with the point of the lance and striking with the edge of the sword as in a tournament, and attacking with the swordthrust and other weapons, as war demands. Geoffroi de Charny, A Knight’s Own Book of Chivalry

A knight carries a double-edged sword, the most honorable of weapons, which can kill by a thrust and with which he can strike both right and left. The sword’s point is the symbol of obedience; for all people must obey a knight. But the two edges are a reminder that the knight is a servant of God and of the people. Life of Lancelot

A spear and sword are terrible, God knows. That is why the knight who carries them is first taught pity, justice, mercy, and only last—force. John Steinbeck, The Acts of King Arthur and His Noble Knights

The skill of knighthood. Your proficiency in the art of combat and violent sport. Also your knowledge of its tools1 and techniques, both in theory and practice. Some common weapons include:

WeaponNotes
SwordPoetically often called a blade or brand. The iconic weapon of the knightly class even though it is primarily kept as a sidearm. Costly and precious, versatile in battle and as a symbol, they are more than the other weapons seen as extensions of their wielder’s arm and soul. Early eras have relatively short blades, but metallurgical advances allow for longer and heavier weapons, called “long” or “great”-swords.
SpearAlso called a lance when used on horseback, while a lighter kind used for throwing is called a javelin. Later forms will form long pikes as well. Spears in all their forms are the most common weapon, both by the common soldier and by knights.
DaggerA knife or dirk, almost always a sidearm or a weapon of opportunity. Larger daggers and smaller swords, like the seax, start to blend together.
AxeA weapon of opportunity in most cases, but sometimes fashioned for war - such as with the Dane axe or long-axe.
MaceVarious kinds of clubs or staves are weapons of opportunity or meant to present less of a threatening profile for enforcement not meant to kill. The mace refers to the deadlier form of these with a heavy metal head capable of providing a strong hammering force - especially useful against heavier armor types where a point or slashing edge has less effect. Later forms may often be flanged, but are not as often spiked or put on chains as the depictions give credit to.
PolearmA wide category of weapons based on a spear-like pole mounted with something more complicated than a spear tip - usually either axe-like or mace-like or both. Includes halberds, glaives, bills and warhammers of many kinds.
BowThe primary ranged weapon of the day. Most bows for war are heavier than those used in hunting (but those may still be weapons of opportunity), but the longbow is especially so; as tall as the archer firing them and requiring tremendous strength to draw. Knights rarely engage in bows in warfare (aside from being the victim of them).
CrossbowA bow-like weapon where the string may be drawn and held in place until a trigger is pulled. Common since ancient days, these have normally been “toy” weapons - unable to get the power of a war bow… but innovations like stirrups, winches and windlasses will be changing that to make the weapon one of the deadliest and most feared by knights.
GunA latecomer to the battlefield, only in the dying days of the campaign, and still in their early forms. The power of the chemical propellant gunpowder is more easily harnessed in the larger siege cannons, but individual hand-guns and arquebuses can use it in a similar niche to the crossbow; power stronger than any man released with a barely trained pull of a trigger.

These are instruments of violence. There may be some applications like tournaments and duels where the violence is “pretend”2 and there’s some uses such as hunting where the violence is not directed towards fellow humans—but most places that truly use this skill3 are when you want to kill someone.

For larger fights, consider The Board and its Pieces.

Footnotes

  1. Of which the sword and the spear are the most prominent in Britain’s martial cultures, but this applies to other weapons as well.

  2. Though never completely. There is no such thing as a safe battle, and while blunted weapons, easy-splinter spears, and tournament armor are made to reduce the deaths - whether by accident or malice it’s never far away.

  3. Light exercise of simple weapon skills, like a crossbow in a hunt, may not need a lifetime of training with these weapons. Sure, it can help—especially if you want to get fancy, but this is about using it in places where it is hard.