Why are swords the primary weapon in most fantasy fiction? I was tempted to write in Western, medieval-inspired fantasy, but that is not even true! It is far more general. Whether East or West, medieval or gunpowder, swords frequently make an appearance. They even make appearances in space fantasies like Star Wars.
The reason why is obvious, of course. Swords are very cool.
What’s interesting is how little swords were used in the military during the relevant reference time period at least in Western history. Armor and mail is extremely tough to cut so stabbing and blunt weapons were more useful in war. In Greek times, the spear was the primary weapon with the sword the secondary, backup weapon. The swords in fantasy are twirling, slashing weapons used by people wearing full suits of often legendary armor.
But there is no Mace of the Dead Goddess Trivian, no Spear of Yava the Flame-Touched. Obviously, it has to be a sword to be a legendary weapon. So what is about swords that makes them inspire awe?
Surprise. I think the first aspect of swords that makes them great for fantasy is by their cutting nature, the battle can change suddenly. One slice is enough to recover from near defeat. Spears satisfy this requirement as well. One well-timed thrust is enough. But this doesn’t really work for blunt weapons. If you are losing a fight with blunt weapons, that means you are getting hit. Hard. If you watch boxing, you’ll notice that the first guy to take a full hit may get up and keep going, but he’s more sluggish than before and the fight usually gets away from him. Furthermore, one good hit isn’t going to change the fight if you’ve been being beaten down the whole time. The hero needs to be at the edge of defeat until the sword just slips below the enemy’s guard.
Variety. Swords can be used in a great variety of ways within a single battle. This generates variety in the fight scene and makes sword battles more exciting. Blunt weapons can also do this, but spears are pretty much a stabbing weapon and have limited variety. The vernacular of what a fight scene should look like is so ingrained that the spear fight between Achilles and Hector in the Troy movie has some moments where Brad Pitt essentially swings the spear as if it is a slashing weapon.
Shiny. Swords are shiny over a greater surface area than blunt weapons or spears. This is very important. Shiny things are, of course, otherworldly, god-touched, etc.
Axes deserve honorable mention for satisfying the Surprise and Variety conditions for a legendary weapon, and there are books with legendary axes. They are not as Shiny though. Anecdotally, I’ve noticed legendary axes tend to be legendary because a famed warrior used it where legendary swords are more frequently Gods-touched.