That's what I thought also, but in game mechanics, cut scene animation, and promotional video suggest otherwise... Apparently there is a physical saber under the beam of energy?
- Sith Warriors have an attack where you simply swing your saber harder to do more damage. If it is only a beam of energy, it should do the same damage no matter how hard you swing it.
- Cut scenes and video clearly show "character A" stabbing "character B" with a light saber, then physically pulling it out of the dead victim; if it was only beam of pure energy, would this be required?
Of course I am tongue-in-cheek about this, light sabers are supposed to be pure energy... but I have noticed the flaws in cut scenes and videos that seem to depict light sabers as having physical elements. Of course those scenes of light sabers being pulled out of the body of a victim were done purely for dramatic effect, but for any Star Wars purist or anyone who notices logic and consistency, those scenes are problematic.