piranha1: As in the title, I have some saved skill points, and with a level up coming up, I'm thinking to put enough of them in "Use Magic Device" skill to be able to cast Knock from scrolls, but I don't know, how many would that be.
I checked with NWN wiki, but the only information it has, is that at Hardcore (or higher) difficulty level (at which I'm not playing) I'd have to make a DC check of 25+ spell's level to use a spell scroll.
How exactly does Use Magic Device work anyway, does it use a roll every time a character is trying to use an item like a scroll, or does it use "Take 20" (
http://nwn.wikia.com/wiki/Take_20 ) if not in combat, or in yet another way (and if so, how?) ?
I found this:
As with most items with use restrictions, scrolls with class restrictions can be used by characters with sufficient skill levels in use magic device (UMD). However, under the "Hardcore" (or higher) difficulty setting, there is an additional check if the module was made after Hordes of the Underdark was released.
The standard UMD check is used to determine whether or not the scroll gets highlighted in red. If given a red highlight, the scroll simply cannot be used. As a general guideline, it takes a UMD score of 1 to use a (class-restricted) scroll with a spell of innate level 0 to 4, UMD 5 to use levels 5 to 8, and UMD 10 for level 9. The requirement for an individual scroll may vary, especially if the caster level is much higher than the minimum for the spell in question.
The additional check is performed after the scroll is used, but before the spell is cast. This check is a standard skill check (d20 + skill level) against a DC of 25 + spell innate level. If this check is passed, the spell is cast normally. If the check is failed, the spell has no effect (but the scroll is still consumed). This check is not rolled (automatic success) if the scroll has no class limitations, the character has at least one bard, sorcerer, or wizard level, or if the character has the spell in question prepared (ready to cast). It does apply to all other characters who have at least one level in rogue, shadowdancer, or assassin, even if that character has a class that is allowed to use the scroll normally.
If you are going primarily Rogue, it might be worthwhile to keep UMD maxed, so you can use other equipment (ex. Monk boots).
I believe UMD doesn't actually make any rolls. Each item with a class (or w/e) restriction has a minimum required UMD skill level, and if your skill level meets that minimum, you can use the item.
