Use Magic Device limitations

[SolitonMan]

I apologize if this topic has been discussed previously, I tried to search for existing threads but for some reason the search page is just hanging and returning nothing at the moment...

I'm playing a warlock in a high level (17+) game, and I've been very pleased with the usefulness of UMD. But I'm not sure about exactly how far it can be pushed to really take advantage of a high skill modifier. I'm hoping others with experience with the skill might have some insights.

Specifically, I'm at a point in the game where I can create custom magic items, and I've been thinking about how I can use the functionality of a staff with the UMD skill. The basic activation of a staff (DC 20 according the skill description) is easy enough, but since a staff allows the wielder to use their own caster level and ability score to determine spell effectiveness and DC, I'm wondering if I can use my (superior) UMD options for these things, or if I'm limited to using my existing scores.

I can see it working either way, but obviously I'd like to have some basis in reality for my position when it comes time to use this in the game. To get a bit less abstract: if I want to use a staff of divination to cast tongues on myself and I just use the default DC 20 activation, the spell will last 130 minutes, since the staff has a caster level of 13. But if I were to emulate the wizard spellcasting feature with UMD, my effective CL would be 32 (UMD modifier of +42, ability to take 10 any time due to warlock's Deceive Item feature gives score of 52, minus 20 for determining CL). Thus tongues would last 320 minutes under that situation, a significant improvement.

Similarly, if I were to activate an offensive spell with a save DC, I could easily emulate a much higher relevant ability score (like, 37) than I (or the staff's creator) actually possess, thus increasing the save DC.

On the one hand, the ability to work the devices this way seems a little "too good to be true", but on the other, spending all the skill points to get this skill to where it is seems like it should provide some ROI.

Anyway, if anyone has any experience with this, any thoughts about it or, most desirably, any links to official rulings, I'd really appreciate hearing about them. Thanks in advance for any help you can provide.

 

[Alexander123]

I'm not sure what the rules have to say on this but a CL of 32 seems to be wrong.

 

[SolitonMan]

I'm not sure what the rules have to say on this but a CL of 32 seems to be wrong.

Mathematically wrong or wrong from a power perspective?

 

[Alexander123]

From a power perspective. Should have been more clear.

 

[Sekhmet]

Staffs use the wielder’s ability score and relevant feats to set the DC for saves against their spells. Unlike with other sorts of magic items, the wielder can use his caster level when activating the power of a staff if it’s higher than the caster level of the staff.

You can increase the DC.
You can use your caster level if it is higher than the staff's.
To use the Staff of Divination (CL13 Tongues), you make your UMD check to Emulate A Class Feature (DC 20) at -20.

If you succeed (rolling an adjusted 40), the spell is activated (should you know the other aspects of activation).

To activate it as a higher level, you must be a higher CL than the Staff's CL. As a Warlock, your CL is your Warlock level. We'll assume it is 20 for this case. CL 20 Tongues lasts for 200 minutes.

The Wizard does not have a class feature called Spellcasting, for one. Secondly, a Wizard's CL is all of his arcane casting levels combined, NOT a class feature. You could not make a UMD check to emulate a higher CL.

 

[TanisFrey]

I believe that by RAW you can increase you effective caster level for a staff with UMD. You cannot raise the effective stat beyond the minimum required by spell.

For the caster level I would require you to declare you wanted caster level and set the DC based on that. If you fail to get the DC the staff could it malfunction on you for pushing it to hard. This could be real bad depending on spell you were trying to get out and your DM mood.

And if you try for a CL with a Holy Word spell (or Blasphemy, Dictum or Word of Chaos) and make it too well with the UMD you could kill yourself, no save.

 

[SolitonMan]

From a power perspective. Should have been more clear.

I kind of figured you meant power level, that's what the "" was for. I kind of agree, but I don't get a good sense of limitations from RAW.

You can increase the DC.
You can use your caster level if it is higher than the staff's.
To use the Staff of Divination (CL13 Tongues), you make your UMD check to Emulate A Class Feature (DC 20) at -20.

Not sure I'm understanding this, the check to emulate a class feature is a straight DC 20. The effective CL for that feature is UMD check - 20. At least according to what I'm reading at Use Magic Device :: d20srd.org

If you succeed (rolling an adjusted 40), the spell is activated (should you know the other aspects of activation).

To activate it as a higher level, you must be a higher CL than the Staff's CL. As a Warlock, your CL is your Warlock level. We'll assume it is 20 for this case. CL 20 Tongues lasts for 200 minutes.

The Wizard does not have a class feature called Spellcasting, for one. Secondly, a Wizard's CL is all of his arcane casting levels combined, NOT a class feature. You could not make a UMD check to emulate a higher CL.

Right, my bad, I meant "Spells".

I believe that by RAW you can increase you effective caster level for a staff with UMD. You cannot raise the effective stat beyond the minimum required by spell.

I can see this, since having a minimum stat is a scroll requirement, not a staff requirement. UMD is silent on emulating ability scores for activating spell trigger items (wands, staffs) so I'd guess I'd have to lean towards the "if it doesn't say you can do it, then you can't" camp.

For the caster level I would require you to declare you wanted caster level and set the DC based on that. If you fail to get the DC the staff could it malfunction on you for pushing it to hard. This could be real bad depending on spell you were trying to get out and your DM mood.

And if you try for a CL with a Holy Word spell (or Blasphemy, Dictum or Word of Chaos) and make it too well with the UMD you could kill yourself, no save.

Good observations, although I'd never attempt to activate anything with a UMD check beyond what I could get by the default take 10 ability of Deceive Item.

Thanks for the replies everyone!

 

[Sekhmet]

Not sure I'm understanding this, the check to emulate a class feature is a straight DC 20. The effective CL for that feature is UMD check - 20. At least according to what I'm reading at Use Magic Device :: d20srd.org

That is what I meant, I worded it poorly. Thanks for pointing it out.

The -20 to CL means you would have to get an adjusted roll of 34 or better to have a better effect than the Staff's natural CL13.
I see no reason whatsoever why you should be unable to use the staff to greater effect when you have a +24 UMD or better (Since you said you'd only ever "Take a 10").

 

[SolitonMan]

That is what I meant, I worded it poorly. Thanks for pointing it out.

The -20 to CL means you would have to get an adjusted roll of 34 or better to have a better effect than the Staff's natural CL13.
I see no reason whatsoever why you should be unable to use the staff to greater effect when you have a +24 UMD or better (Since you said you'd only ever "Take a 10").

Got it, I'm on the same page with you now.

Yes, by maxing out UMD and having my artificer cohort enchanting one of my rings with UMD +15, my warlock has a UMD modifier of +42 at level 18 (21 ranks, +15 competence bonus from ring, +6 charisma modifier). So taking 10 gives me a check of 52, which works out to a CL of 32.

Any wonder why I'd want to use that as my CL for a staff?

It seems as though there's nothing in RAW that would prevent this. I don't see a problem personally - it works both ways, for PCs and NPCs, and honestly, in the games I've played since 3rd edition came out, I don't really see UMD getting the use I think it deserves.

Thanks to everyone for your comments, if you have more please add them!

 

[Alexander123]

I don't think you can take 10 on a UMD check