The 3E "brilliant energy" weapon always gets pointed to as "like a lightsaber", but it's nothing like a lightsaber.
Brilliant energy: NO EFFECT ON INANIMATE MATERIAL.
Lightsaber: Cuts metal and stone.
It looks the same as the 1e days I have no clue about 3 or 4 editionsIn prior editions, the sun blade seemed like a regular sword that had the ability to light up. In 5e, it's very much a lightsaber.
Nothing wrong with that, of course.
However, I have to ask - was my original assumption that the sun blade was an actual sword correct, or has it been a lightsaber all along? I've looked back to the 2e and 3e descriptions, and I could see it going either way.
Thoughts?
The 3E "brilliant energy" weapon always gets pointed to as "like a lightsaber", but it's nothing like a lightsaber.
Brilliant energy: NO EFFECT ON INANIMATE MATERIAL.
Lightsaber: Cuts metal and stone.
It's *like* a lightsaber. It's not *identical* to a lightsaber. It's certainly not *nothing* like a lightsaber. A cabbage is nothing like a lightsaber, as is a velociraptor. A brilliant energy weapon is definitely like a lightsaber.
That's mostly because a real lightsaber that cuts metal and stone is ridiculously useful. We had a DM that made the mistake of giving us one in 2e. It worked exactly like a lightsaber... for about three sessions. Then it basically functioned like a brilliant energy weapon. A real lightsaber is too useful.
I'd say it's less like a lightsaber than a flame tongue is. It does not in any way make me think "lightsaber" because the defining characteristic of brilliant energy weapon is "no effect on inanimate objects", and that's... pretty much not even part of lightsabers.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.