Object Transmutation.

[Seffbasilisk]

A character I have owns a +1 Great Scimitar. Immense symbolic and sentimental value to him. Now I was wondering, if there was a way, for at higher levels, to get it changed from Steel to Adamantine or another material similarly resistant to sundering.

I was originally thinking Polymorph Any Object. Then I read it has to be non-magical. Ok. Targeted Dispel Magic, Polymorph Any Object. It turns, then the magic returns. Then I continued on to read the fateful line

This spell cannot create material of great intrinsic value, such as copper, silver, gems, silk, gold, platinum, mithral, or adamantine. It also cannot reproduce the special properties of cold iron in order to overcome the damage reduction of certain creatures.

So now I turn to you fair folks, to tell me...is there any way that this sword can be better preserved? Or is it doomed to be a rust-monster's easy meal?

[Jasdoif]

You're aware that a rust monster can snack on adamantine or any other metal as easily as it can steel, right?

Anyway, this sounds like something that makes an acceptable wish. Afterall, transform metal to wood states that a wish can restore the afflicted items to their former metallic state, I don't think going from steel to adamantine is too much of a stretch. It's only a 3,000gp increase in market price after all, well within wish's 25,000gp safe limit for nonmagical items (and you aren't altering the magic properties, so I think it's a fair use).

[Artemician]

Do it the old fashioned way.

Pull something. Like, invent a custom spell called "Transform Steel to Unobtanium". Have the sword melted down and it's fragments reforged into an alloyed blade. Have it Titanium-coated. Etcetra

Seriously, if something is more fun for the group, and the rules don't allow it.. I would put having fun first.

The rules serve the game, not vice versa.