How does Use Magic Device work with scrolls?

[nittanytbone]

How does Use Magic Device work?

This is how I THINK it should work. Let me know how I'm wrong.

Gord the Rogue has a +7 UMD check. He wants to use a mage scroll of "fly" (3rd level spell).

Here's how scrolls work from the SRD:

The spell must be of the correct type (arcane or divine). Arcane spellcasters (wizards, sorcerers, and bards) can only use scrolls containing arcane spells, and divine spellcasters (clerics, druids, paladins, and rangers) can only use scrolls containing divine spells. (The type of scroll a character creates is also determined by his or her class.)
The user must have the spell on his or her class list.
The user must have the requisite ability score.

If the user meets all the requirements noted above, and her caster level is at least equal to the spell’s caster level, she can automatically activate the spell without a check. If she meets all three requirements but her own caster level is lower than the scroll spell’s caster level, then she has to make a caster level check (DC = scroll’s caster level + 1) to cast the spell successfully.

Ok, the last one is easiest (have the requisite ability score). Gord has Int 14, so he has the requisite ability score.

The middle requirement is tougher. Gord has to make a UMD check DC 20+spell level to meet this requirement (have the spell on his class spell list). That means he needs a 23, and with a +7 check he needs a 16 or better on his D20 roll. Let's say that he makes his roll.

The final requirement is a caster level check. Gord's level in wizard is 0. So, he can make a CL check DC 6 (effectively just a D20 roll), or he can make a UMD check to "Emulate a Class Feature" (i.e., wizard level 5) DC 25.

If he passes this roll, the spell goes off.

Is that right?

What happens if a roll is failed? Is the scroll lost? Does he have to make a DC5 wis check to avoid a mishap? Is UMD actually useful, given the high check DCs and inability to take 10 on rolls?

 

[UltimaGabe]

SRD: Use a Scroll: If you are casting a spell from a scroll, you have to decipher it first. Normally, to cast a spell from a scroll, you must have the scroll’s spell on your class spell list. Use Magic Device allows you to use a scroll as if you had a particular spell on your class spell list. The DC is equal to 20 + the caster level of the spell you are trying to cast from the scroll. In addition, casting a spell from a scroll requires a minimum score (10 + spell level) in the appropriate ability. If you don’t have a sufficient score in that ability, you must emulate the ability score with a separate Use Magic Device check (see above).
This use of the skill also applies to other spell completion magic items.

In order to activate a Spell Completion item, you simply need to make a UMD check equal to 20 + the caster level, as well as a UMD check to emulate the requisite ability score (if his ability score isn't high enough). A failed UMD roll simply means you fail to activate the item. It's not wasted, and you can try again the next round (or whenever you would otherwise be able to use the item again). The only exception is if you roll a natural 1, AND if that natural 1 causes you to fail, then you can't activate that particular magic item until 24 hours have passed.

In short, UMD isn't extremely useful at low levels- the DCs are all very high, and you can't take 10, so there's almost always gonna be a chance of failure. However, at higher levels, it's amazing- once you've got a high enough modifier (that is, at least +15), you can activate all kinds of items you otherwise wouldn't be able to with little or no chance of failure. After all, activating a wand of any sort is only a DC 20, if I'm not mistaken, as long as you know what spell is inside- so if you ever wind up with a +19 (10th-level character with 13 ranks, a +3 from a 16, and, say, Skill Focus: UMD, or just a higher-level character with more ranks) you'll never have any chance of failing to use a Wand.

It can be amazing, but only if you invest a LOT of ranks in it.

 

[UltimaGabe]

(Oops... double post.)

 

[Peter Gibbons]

Ok, the last one is easiest (have the requisite ability score). Gord has Int 14, so he has the requisite ability score.

Correct. If Gord didn't have at least a 13 Int, he would have to Emulate an Ability Score (Use Magic Device DC 28).

The middle requirement is tougher. Gord has to make a UMD check DC 20+spell level to meet this requirement (have the spell on his class spell list).

This is not a requirement to activate a scroll using UMD. The skill "allows you to use a scroll as if you had a particular spell on your class spell list." (PHB, p.86) The DC is 20 + the caster level of the spell...in this case, 25.

The final requirement is a caster level check.

Again, no. You simply make the UMD check as described above.

What happens if a roll is failed? Is the scroll lost?

No. A magic item that fails to activate simply does nothing.

Does he have to make a DC5 wis check to avoid a mishap?

No.

Is UMD actually useful, given the high check DCs and inability to take 10 on rolls?

Yes.

 

[Legildur]

...Is UMD actually useful, given the high check DCs and inability to take 10 on rolls?

Yep. The Rogue in our campaign takes all the hand-me-down wands from the wizard and blasts away with about a 90% success rate. It gives him something useful to do when flanking for sneak attacks is inappropriate for him.