Them thar crystals...

Do they work on custom items? I guess there's no reason why they wouldn't but thought I'd ask anyway, just in case!

(Though I suppose if I ever wanted to upgrade said custom item with another voucher in the future, I'd lose the crystal benefit after receiving the new item in game... )

Yes, if a standard item of the same base item type accepts the crystals, a voucher item of the same type will as well (IOW, no crystals on CEP base weapon types, and no smite crystals on mage staffs)

Out of curiosity, what weapons fall under the CEP base weapon types?

Well, I know the Falchion does.

Which is why I made a halfling scimitar specialist.

I'm pretty sure that any item that is CEP based has an asterisk next to the base item type.

Knows ye if the kukri is CEP based? If so, I have two that are fully crystalled.

Standard NWN base melee weapons: dagger, short sword, longsword, bastard sword, greatsword, club, mace (not to be confused with CEP's "heavy" mace), light hammer, war hammer, light flail, heavy flail, rapier, scimitar, kukri, kama, battle axe, dwarven war axe, hand axe, double axe, dire mace, two-bladed sword, quarterstaff, katana, scythe, morningstar, halberd, great axe, whip, sickle, spear, and trident....

Anything who's base item type isn't one of those... is CEP.

The trident weapons can be kinda confusing too because there's the NWN trident, and then the CEP trident. The NWN trident is two handed, the CEP is 1 handed (and if I recall, it's base item type is listed as "trident(one handed)".... no asterix as with the other CEP base item types.

ah. Thank you, mr. manny!