> For bonus points, energy weapons weren't really used because if one hit a shield, it would cause an explosion

This never really made much sense to me. IRRC when an energy weapon hits a shield either the emitter or the shield generator blows up. Since shields are protecting something while the emitter can be anywhere to me the logical outcome seems to be energy weapons everywhere and no shields at all.

It totally did not make sense. Anyone would be able to generate a massive explosion from readily available components. And there's no explanation where that energy would come from.

A small edit that would make this work: energy beam weapons could not penetrate a shield, and just reveals the location of the shooting weapon.

That's desperately trying to tweak the technology so that he gets a society where knife fighters matter. Actually, those knife guys would be vulnerable to ordinary riot-control weapons - tear gas, Mace, flash-bangs, big plastic shields, etc. Or an RPG with a solid warhead to knock someone out of the fight by sheer kinetic energy. Herbert was writing before every combat organization had RPGs.

There is mention that the shields act as molecular filters, protecting against poison gases. And the shockwave energy of an explosion was negated as an excessively fast high/low pressure wave front. Same with flash bangs. Big plastic shields are just another close quarters combat device, and not particularly useful unless in a phalanx.

Mass times velocity equals mass times velocity. If you're hit by a solid round with an RPG rocket behind it, you're going down, no matter how good your forcefield armor is. Momentum is roughly that of an entire NFL offensive line.