[Pursuivant]

Lower lethality levels could also be a justification.

If you want to be highly cinematic, you could rule that only guns/blasters kill, so if you want to keep foes alive you attack them with melee weapons or unarmed attacks.

To make it less cinematic, you can rule the same, but only for less than overwhelming crushing attacks (e.g., high speed crashes or falls from high places), with the justification that there's some sort of spiffy ultratech medicine which instantly mends bruises, broken bones, and subdural bleeding - or at least keeps them from killing the victim.

If you want to be realistic, invent some sort of stunning melee weapon, plus good armor which is proof against most handguns and light beam weapons.

There's also the "Dune" option, which supposes that there is personal force field technology which works best at stopping beams and high-speed, low-mass projectiles. As a result, combat consists of fencing light, thin, blades and slow thrusts through the force shield are the most lethal.