The Phase Blade

[Afgncaap5]

Is there a weapon in 3.5 D&D that is, effectively, just a miniature portal?

I was talking to my Dad about gaming, and while he's never cared for 3.5 he was a big 1st edition player back in college and seminary, and the topic of Vorpal blades came up. He asked if it was pretty much just an outline of a sword, with the faint image of darkness and stars on the other "side" of the outline, effectively allowing it to cut through anything.

I vaguely recalled him talking about that kind of sword before, especially when I was first playing through Infocom's Zork games. Beyond Zork gives you a weird "phase blade" that is suggestive of that property even if it doesn't directly say so (and the sword doesn't seem to properly "exist" unless you're in the ethereal planes/heaven.)

So, both for my curiosity, and for my dad's, was this sort of "phase blade" ever a thing in D&D? Is it a thing in 3.5 that I'm not familiar with? I suppose you could sort of simulate this by saying that a phase blade "always hits on a touch attack" and "ignores damage reduction, hardness, and regeneration", but I'd be curious to see if I could find something without homebrewing.

On another note: I've always been kind of underwhelmed by the Vorpal property in 3.5; I'm a big Lewis Carroll fan and wanted the sword to be more than "lets you auto-kill enemies by beheading them on a crit." So... is there any chance that vorpal meant something different in previous editions that might be more interesting?

[Deophaun]

There is and there isn't: it's a spell called black blade of disaster, which you can find in the Spell Compendium. Which makes sense that it wouldn't be a proper weapon: if it destroyed anything it came into contact with, there wouldn't be any way to wield it.

[Zancloufer]

There is the "Brilliant Energy" property which causes the blade to ignore "non-living" manner so it ignores AC granted by (Natural) Armour. Pretty much a touch attack there. Make it out of Adamantium and it also ignores hardness and all material based DR. Add something like Trollbane poison to overcome regeneration and you pretty much have a sword that attacks touch AC, ignores most DR/Hardness and can overcome regeneration.

[Deophaun]

Make it out of Adamantium and it also ignores hardness
Of questionable use since it ignores non-living matter; no use versus doors or constructs.

and all material based DR
Still subject to DR/Silver and DR/Cold Iron. And since brilliant energy doesn't work on non-living matter, you probably aren't going to run into anything with DR/Adamantine that you can hurt.

[eclipsic]

Your dad is probably talking about Blackrazor, one of three minor artifacts around which the White Plume Mountain adventure is built. If you do an image search for Blackrazor, you'll see what you're describing. Also, previous editions of D&D feature a vorpal weapon, which was a +5 weapon IIRC, that beheaded your opponent on a natural 20.

[Thurbane]

As eclipsic points out, sounds like your dad was referring to Blackrazor.

In the 3.5 free adaptation of the adventure (http://bothgunsblazing.com/adventures/WhitePlumeMountainRevised.zip) on the WotC website, it got statted out as a legacy weapon.

https://image.ibb.co/fG8hrF/Capture.jpg