In the Star Trek series, the movie Blade Runner, and even iconic universes like Star Wars, blasters, ray guns, and other futuristic weapons are commonly used. However, in the world of Dune, which inspired the creators of all these projects, characters prefer to fight with swords, daggers, and stilettos. Why is that in a technologically advanced future where humans have long been traveling between stars, predicting the future, and performing mental calculations better than any computer?
Holtzman Shield: Why Firearms Became Useless
In the first part of Dune by Denis Villeneuve, there are no direct explanations about why characters use knives instead of blasters. However, observant viewers notice the energy shields that envelop the bodies of fighters, flickering with blue or red light during attacks. These are the Holtzman Shields, the main factor that made firearms and laser weapons almost useless.
- Bullets, lasers, arrows — any ranged weapon simply bounces off the protective field, causing no harm.
- Slow strikes get through — that's why swords, daggers, and stilettos became the primary weapons in battle

This is why, in the world of Dune, warriors returned to blades, and the art of fencing became a vital skill.
How the Shields Work and Why They Are Not Absolute Protection
Frank Herbert explained in his books how this futuristic barrier works. The shield allows slow movements to pass through — this is designed so that the wearer can still breathe and move. If the shield blocked everything, it would suffocate the wearer. When a fast strike (like a bullet) occurs, the shield instantly activates and deflects the threat. But if the weapon moves slowly, it can penetrate the shield and harm the opponent.
Swords Are the Perfect Weapon for a New World, but There's a Catch
The shields made ranged weapons useless, but warfare did not disappear in the world of Dune. Instead of long-distance shootouts, great houses began training warriors capable of hand-to-hand combat. But ranged weapons haven't disappeared; they are just used cautiously.

Blasters and machine guns are still relevant, but only in limited situations. For example, the Fremen do not wear shields because they would attract sandworms, so they can be shot from a distance.
"Slow" bullets can penetrate the shields. These projectiles move slowly but rotate at low speeds, pressing through the barrier. This is how Duke Leto Atreides was killed.

The lasgun (laser weapon) is so dangerous that almost no one uses it. If the beam hits the shield, a massive explosion occurs, destroying both the target and the shooter. It is only used in suicidal missions. There's also nuclear weapons, which all the houses pride themselves on but only use for intimidation.