Question(s) about Use Magic Device

[Constance Clochard]

I've worked myself in circles about this Skill and how and when to use it.

Here's my basic starter questions:

A rogue is trying to use a Wand of Melf's Acid Arrows. Never used it before. What DC is used? Activate Blindly for a DC of 25 (if successful subsequent uses get a +2) Or Use Wand or a DC of 20?
If the UMD roll isn't successful does the wand loose a charge?

Let's say the party Cleric has sunk some points into UMD. The Cleric attempts to use the Wand of Melf's Acid Arrows. Never used it before. What DC is used? Activate Blindly (DC 25) or Use Wand (DC 20)?

Would a character that can cast arcane spells ever need to roll a UMD to use the Wand of Melf's Acid Arrow? When?

I'd assume that when UMD is involved it takes atleast two success die rolls to accomplish something - first the UMD roll and then the To Hit roll. There may be magic resistance or a saving throw involved...

Thanks,
Con

 

[Vegepygmy]

A rogue is trying to use a Wand of Melf's Acid Arrows. Never used it before. What DC is used? Activate Blindly for a DC of 25 (if successful subsequent uses get a +2) Or Use Wand or a DC of 20?

If he knows the command word, 20. If he doesn't know the command word, he has to activate it blindly (25). Once he's successfully activated it blindly, he still doesn't know the command word, but he gets a +2 on his roll.

If the UMD roll isn't successful does the wand loose a charge?

No. A charge is used only if the wand is activated. The same is true for a scroll, etc.

Let's say the party Cleric has sunk some points into UMD. The Cleric attempts to use the Wand of Melf's Acid Arrows. Never used it before. What DC is used? Activate Blindly (DC 25) or Use Wand (DC 20)?

Unless the cleric has Melf's acid arrow on his class spell list, it works just like it does for the rogue.

Would a character that can cast arcane spells ever need to roll a UMD to use the Wand of Melf's Acid Arrow? When?

"Arcane spells" are irrelevant. The question is whether the character has Melf's acid arrow on his spell list. If he does (even if it's a divine version of the spell), he can activate the wand without UMD. If he doesn't, he can do so by using UMD.

I'd assume that when UMD is involved it takes atleast two success die rolls to accomplish something...

Not necessarily, but in the case of Melf's acid arrow, yes, there would be an attack roll as well.

 

[akbearfoot]

If the party has identified the wand already, then its not considered 'activating blindly'. If its a magic stick they just found in a dungeon and the rogue wants to try and activate it then he uses the higher DC.

Pygmy's answers all seem correct to me.

 

[irdeggman]

No. A charge is used only if the wand is activated. The same is true for a scroll, etc.

I think it also happens with a mishap result too.

 

[Vegepygmy]

I think it also happens with a mishap result too.

That's correct. A mishap counts as an "activation."