3.5 adding armor enchantments

[JohnStone]

If I wanted to add an enchantment to unique armor...
Is it possible, does it cost extra?

Specifically I want to add "Soulfire" to a "mithral full plate of speed"

[Red Fel]

If I wanted to add an enchantment to unique armor...
Is it possible, does it cost extra?

Specifically I want to add "Soulfire" to a "mithral full plate of speed"

You may want to post this in the appropriate subforum (http://www.giantitp.com/forums/forumdisplay.php?59-D-amp-D-3e-3-5e-d20).

And in answer to your questions: Yes, it is possible, and yes, it costs extra (http://www.d20srd.org/srd/magicItems/creatingMagicItems.htm#addingNewAbilities). It gets trickier when you're using unique items as opposed to regular magic items, but in my experience most DMs will allow it.

In any case, Mithral Full Plate of Speed (http://www.d20srd.org/srd/magicItems/magicArmor.htm#mithralFullPlateofSpeed) isn't so much unique as it is specific (http://www.d20srd.org/srd/magicItems/magicArmor.htm#specificArmors): it's a suit of magic armor "usually . . . preconstructed with exactly the qualities described here." Specific items are basically magic item bundle packs - a set of complementary, thematic enhancements on a single item. Nothing stops you from adding more to a specific magic item, just as you would any other magic item.