Question on Use Magic Device skill

[Mordeth]

How exactly, down to the DC's needed, does it work.

I understand how to cast from a scroll.
d20 - UMD# = effective caster level.

But to decipher the scroll, you need a UMD DC25 to be able to read it. Is there a retry if you fail? Or is it that you can never read that particular scroll?

Failing the caster level, its just a DC5 wis check to not have a mishap.

To use wands is the Emulate Spell Ability. It says "For wands, it doesnt matter what your caster level is, but it does for scrolls."
SO, what DOES that mean? I dont need to roll, just have 1 point in UMD???

And what about staves and rods, how does UMD affect them?

And to just be clear about what I need, answer this example.
10th level char, 5rogue/4fighter 10 CHA 10 INT 14 WIS and 10 in UMD.

Activating an arcane scroll of melfs acid arrow, 3rd caster level.
Using a arcane wand of fireballs, 5th caster level.
Using a Staff of Life, cure serious wounds, 1 charge.

If you can answer the questions, with each and every roll needed, I think that would clear it up for me, Thanks a ton guys.

 

[reiella]

Scroll users need to be of high enough caster level to activate the scroll (else potential for mishap, and other fun stuff).

Wands lack this restriction.

Since Staves and Rods (I believe) don't have a caster level dependant effect on activation, caster level isn't signifcant for them.

Someone will correct me if I'm wrong I'm sure .

[ Add ]
So yes, with a single rank in UMD, if you can make the UMD activation check, you're ok. If trying with a wand, you may result in mishap.

Also should be noted that you generally can't take 10 on the Mishap check (someone will correct me if I'm wrong here though).

 

[Christian]

Everything's listed on the chart for the skill, on page 75. Some of the categories may not be as clear as they could be, I suppose ...

To use a wand of Magic Missile, you need to have the Magic Missile spell on your class spell list. A UMD check at DC 20 lets you emulate that spell ability and use the wand. (You can imagine this as giving you caster level 0, as if you were a first-level multiclass spellcaster. This is sufficient to use any wand with a spell on the class list.) Same deal for rods, staves, wondrous items with class limitations, etc., using the 'emulate class feature' DC 20 check.

The deciphering a spell ability works just like using Spellcraft to decipher a spell, but has a DC five points higher. As stated under the Spellcraft skill, you can attempt this once per day. Once you succeed, you can attempt to use the scroll anytime you wish.

Using a scroll (that you have previously deciphered) works just like it does for a spellcaster, except your effective level is your UMD check roll minus 20. Note that if you don't roll at least 20, you can't use the scroll at all (you've failed to emulate the spell ability required). Otherwise, you make a caster level check (1d20 plus your UMD check -20) against a DC of the scroll's caster level +1. (This is an automatic success and therefore unnecessary if your effective caster level meets or exceeds the caster level of the scroll.)

Whew! Any questions?

 

[Mordeth]

Everything's listed on the chart for the skill, on page 75. Some of the categories may not be as clear as they could be, I suppose ...

Otherwise, you make a caster level check (1d20 plus your UMD check -20) against a DC of the scroll's caster level +1. (This is an automatic success and therefore unnecessary if your effective caster level meets or exceeds the caster level of the scroll.)

Whew! Any questions?

Wow, thanks alot, that made a hella lot sense. I dont understand that last part though, Why is it an automatic success? Me being a rogue would have to roll for that right?

So that's two checks to cast from a scroll?

BTW, you da man!

 

[Thanee]

When you cast from a scroll you first make a UMD test to enable you to do it in the first place, this must result in at least 20 (remember the possible +4 synergy bonus from Decipher Script and Spellcraft, which could be helpful). Your caster level will then be your UMD result - 20 (at least 0, as you must beat 20) for this purpose.

If your caster level now equals or exceeds the caster level of the scroll (usually (spell level x 2) - 1), you don't need to roll anything else, you can just read the scroll and it succeeds.

If you end up with a caster level below the required one, you still have to do a caster level check (every caster has to do this, if he reads a scroll too high for his level). The DC is the scroll's caster level + 1. This is listed in the DMG in the magic scrolls section.

Bye
Thanee

 

[Christian]

So that's two checks to cast from a scroll?

BTW, you da man!

Conceivably three checks, as you also need to decipher it. This can be done beforehand, though ... And if your UMD check is high enough, you wouldn't need to make a caster level check, as Thanee notes.

 

[Mordeth]

Gotcha, thanks again you two.

 

[Shallown]

UMD is one of the most powerful and useful skills a rogue can have concentrating in it and aquiring a magic item with a skill bonus to it makes for a very versatile rogue. But to actually contirbute to this.

Using a scroll requires a stat equal to 10 plus spell level. Does this hold true for the rogue. Ie can a wis 13 rogue cast a 4th level cleric scroll spell.

Does UMD allow you to fake stat requirements as well, I don't recall.

Later

PS wands are a rogue's best friend +2 bonus for having used it any buff wand or cure wand can be used by taking ten so at a +11 skill you can use them all out of combat with no problem. So at say 4th level you could use a wand easily (Skill maxed at 7 ranks a +2 mod and +2 for having used it successfulyy once)

Wand cat's grace/bull str curing invisible etc...

Later

 

[Christian]

Good point, Shallown. A scroll might require four rolls for a rogue to use it. (Yeesh!) The UMD skill includes an 'emulate ability score' usage, which is your check result minus 15. So, to use that 4th level cleric scroll (scribed at 7th level), the rogue needs to (a) decipher it (UMD DC 29), (b) emulate the spell ability (UMD DC 20), (c) succeed at a caster level check at DC 8 if the roll in step (b) wasn't at least a 27, and (d) emulate a 14 Wisdom (UMD DC 29).

Get a wand, it's easier.

 

[Thanee]

Using a scroll requires a stat equal to 10 plus spell level. Does this hold true for the rogue. Ie can a wis 13 rogue cast a 4th level cleric scroll spell.

Does UMD allow you to fake stat requirements as well, I don't recall.

Yes, indeed. If the relevant attribute is not high enough (10 + spell level), then the rogue would have to emulate that as well.

wands are a rogue's best friend +2 bonus for having used it

I'm afraid, but I don't think this is correct. This special bonus only applies for blind activation of an item only (which cannot happen with wands, as they do not have command words or similar activation methods).

Bye
Thanee