in Dune, the Sardaukar try to sneak in and attack Paul and Lady Jessica, but after they land and before they enter a gate, they are ambushed by a group of Fremen emerging from beneath the sand.
During the fight, there is no obvious shields, indicated by the blue / red hue, I am wondering why? From the ensuing fight between Duncan the Sardaukar, we can clearly see blue / red hue from their energy shields.
Do Fremen have melee weapons that ignore the Sardaukar energy shields?
The Fremen don't use shields, because shields attract worms and enrage them.
This is mentioned by Kynes when she gives the Atreides a tour of the spice mining operation:
Paul:
Why don’t we just shield the crawlers?Kynes:
A shield is a death sentence in the desert. It attracts the worms and drives them into a killing frenzy.
In the books, the Fremen are openly scornful of the value of shields.
The Sardaukar may not be using shields in this fight, perhaps because they are ambushed, but maybe they are also nervous about attracting worms in this location, which is partially outside (at least it is open to the sky).
In the fight with Duncan, shields are used because both sides are most comfortable with that style of fighting. It is also inside.
