We have this romantic image of heroes, knights in all but name, swords held aloft as they swoop down on the backs of dragons to vanquish their foes. But how realistic is this scenario really? I speak of course not of the giant, half-tamed, fire-breathing lizards, but of the weapons used by their riders.
First, let us examine the fact that any weapon wielded by a person on the back of a dragon is redundant: dragons make pretty awesome weapons in and of themselves. Their fire is a more destructive and accurate than any ranged weapon in a pre-gunpowder society and certainly more incendiary than historical analogues: pots de fer and Greek fire. Their teeth are more powerful than any sword and their claws have greater reach than any spear or pike. Why bother arming the tiny rider sitting on the beast’s back?
If you must arm the rider, let us not treat the dragon like a scaly winged horse. Swords, lances, and bows are useless for anything but ceremonial pomp. A sword is too short to reach anything. Period. A lance has the reach, assuming you can aim it and disengage when it sticks in the foe afterward, but it is impractical and silly. Knights were often thrown from their saddles during lance battles and jousts. That is survivable . . . on a horse. If you’re thrown off your dragon mid flight, all the armor in the world will not save you. In a similar vein, mounted archers were often successful . . . on horseback. Try aiming and firing a bow while riding a roller coaster as it dips and swerves through the air. A. Dragon. Is. Not. A. Horse.
Could dragons be used as a weapons platform like an elephant with a howdah? Maybe, though the analogy is still suspect. If we must compare dragons to anything conventional, let us compare them to airplanes: big things that fly through the air really fast. How would your arm an airplane in a society that lacks the technology to build one? No machine guns, no mortar rounds, and no bombs.
The first airplanes were scouting vehicles and dragon riders could serve well in this capacity. There is nothing more vital in warfare than knowledge of enemy troop movements. Or as previously posited we could use large dragons as weapons platforms, but what sort of weapon would suit best?
Arrows are a step in the right direction, but you don’t need a shaft or fletching or bows to drop a missile and let gravity do the work for you. Darts or lead shot would probably be the most effective. Even random metal shrapnel will become an effective tool for slaughter when dropped onto an army from an airborne weapons platform. And if you miss, well you’ve still got the dragon.