At the bottom of the skill list is this weird skill called Use Magic Device. It lets you use magic items even if you normally wouldn't be allowed, such as wands, scrolls, or holy avenger swords.
If you look over the skill description, you end up noticing that that DCs are pretty high. There is a reason for that because this is perhaps the most powerful skill in the game. If you're bonus is high enough then regardless of your class or your stats, you can wield powerful magic.
The classic image of a character using UMD is the Rogue. Normally just a dextrous and wily fellow, who knows how to sneak about and stab people in the back, the Rogue has the opportunity to invest in UMD and then, with his natural chutzpah, pick up a wand and wave it about “just so” and get it to work for him.
If you want to try your hand at being unconventional in your approach to the game, then UMD is a great way of matching up class features in ways that you don't normally expect in a game. You can do this by investing over time in UMD and then at mid and higher levels be able to start using it effectively. If you want to get a jump on it and start earlier then you need to invest more heavily in it with feats such as Skill Focus and Magical Aptitude, and of course have a high Charisma.
THE OPTIMIZED UMDer
Let's look at a totally optimized UMD character:
First off, you need to be human (for the extra feat), have an 18 Charisma, which you then boost to 20 with the +2 racial bonus (getting you a +5 ability modifier). Next you need to take a level of Alchemist, Bard, Rogue, Sorcerer, Summoner, or Witch so that you can get +3 Class Skill bonus.
Next you'll want to spend your two feats slots at 1st level to get Skill Focus (UMD) and Magical Aptitude. And you'll want to pick up the Dangerously Curious Trait out of the Trait Web Enhancement on Paizo's website. Finally, when you get the money and prestige, pick up a cracked Ioun Stone to give you +1 to your UMD.
You'll end up with:
= +15 bonus
Not bad for an early start!
This tends to be the type of action that is most likely to be used by UMD. Not only because wands give you a good bang for your buck per charge, but they also are the easiest action to try and pull off with UMD. In part this is because the challenge rating for a wand doesn't change. It could be a 1st level spell wand, or a 4th level spell wand and the difficulty is always just a DC 20.
For our optimized UMD user above what
this means that at 1st level they have a success rate of
85%, and at 3rd level they cap out at a “perfect”
success rate of 95%. This translates into a 100% success rate because with the UMD skill there is a subtlety to the rule of failing. The rule states, "Try Again: Yes, but if you ever roll a natural 1 while attempting to activate an item and you fail, then you can't try to activate the item again for 24 hours." Thus, rolling a 1 is not an automatic failure and if you're bonus is high enough then you can activate with impunity.
The next most used action for UMD is casting spells from scrolls. The rub here is that it is a lot harder. You have to make up to three rolls to get a scroll to work. First, you have to decipher the scroll. Normally this uses the Spellcraft skill, but you can use UMD to pull it off. What's happening here is that your character is figuring out what is written on the scroll and understand how to properly cast it.
Next, depending on your ability scores you may need to emulate a higher ability score than what you have. A 3rd level Spell from the Wizard spell list requires at least a 13 Intelligence (it's 10 + Spell Level) and if you only have a 12 Intelligence then you've got to “fake it till you make it” by using your UMD to let you figure out the essential gist to how to pull off casting the spell.
Finally, you have to actually cast the spell from the scroll. As with wands, if you roll a natural 1 on the d20 then you're effort fizzles out and you can't try casting from that particular scroll, for 24 hours.
So when do you get to that 95% success rate with the above optimized UMDer? Unlike wands, it depends on the spell level:
That takes care of normal spell usage in Pathfinder Society. As you know, Pathfinder Society only goes up to 12th level in terms of character levels, at which point your character retires. That means normally, at best, spellcasters can only use 6th level spells or below.
However, the higher level spells that get cut off because of this 12th level cap are still available to be used via scrolls.
So it is possible, by mid levels, to buy a scroll of wish (it only costs a mere 3825gp!) and have it on hand for those moments when you wish... well, for anything.
This is one of the big challenges with UMD. You generally have to spend a lot of gold to get magical items to use on a regular basis. If you come across a magic item in game, then for that session you can go crazy with the item, but beyond that PFS session you'll need to buy the item. Beyond 1st level spells, you're going to need a lot of gold to buy higher level items unfortunately. This means that a character that is focused on heavily using UMD isn't really going to come into their own until mid to upper character levels when you start to get large influxes of gold per session and you've already had a chance to purchase some other needed magic items, such as some of the Big Six.
However, there is one resource that you can dip into to get a healthy spread of wands to grab at a moment's notice. You can spend 2 prestige points that you have earned through faction missions to pick up a 1st level wand. After just a few modules you'll start to accumulate a nice pool of prestige points, so it's possible to have a collection of low level wands that will come in hand in a variety of situations.
The one issue to weigh in this approach of wand accumulation is that when you spend those prestige points, you're making it harder for you to afford to have your character brought back from the dead if fate deals an unlucky blow to your character. Having Raise Dead cast on your character takes 16 prestige points, which if you ace every one of your faction missions, you can't get before your 8th module (which would put you at 3rd level). So that is something that you might want to weigh in how you approach a UMD character.
Because the optimized UMD character doesn't get a 95% success rate until 3rd level, and you might want to wait to spend prestige until you get to 18 points (16 for the Raise Dead “insurance” and 2 for a wand) then it might be more worthwhile to consider making the UMD character really come into its own at 3rd level or above.
WHAT CLASSES WORK THE BEST WITH UMD?
UMD is provocative in two different ways. On the one hand you have the classes that naturally gravitate towards high Charisma scores, such as Bard, Oracle, Paladin, Sorcerer, and Summoner. With all of these classes you want a high Charisma because the class abilities of these classes run off of Charisma, so UMD can help supplement what you are already good at.
However, what makes it more interesting is to have a class that isn't a traditional Charisma class and have it use UMD to give a big boost in the overall versatility to the class. The classic example of this would be the Rogue. Normally Dexterity tends to be the most important ability for the Rogue, but if you emphasize Charisma then you'll be able to not only get a big boost in all of the Charisma based skills that Rogues can spend their large pool of skill points on, but the class can also focus on UMD and be able to be a “mundane” character than can cast a lot of spells through UMD.
Another example might be a Fighter who
invests in some Charisma (or at the very least not dump the stat) and
UMD. Instead of using every possible feat slot for combat feats,
spend a couple to get Skill Focus (UMD) and magical aptitude. That
will allow you to be a very competent martial character, but also be
able to cast spells, something that you won't normally see happening
in the game.
UMD FOR EVERYONE (OR ALMOST EVERYONE)
You say, “But what if I don't want to spend two feats, a trait and a pile of skill points on this one skill? UMD must be worthless to me!”
Not so... the optimized UMDer is jacking it up so high so that when in combat or pressed for time the player knows that the UMD check will work. However, for just a little investment you can get UMD to work for you most of the time if you plan on using it outside of combat. The perfect example is having a wand of cure light wounds. You have a wounded ally sitting there. Even if you have just a +1 to your UMD you can keep tapping your friend with the wand until it either works, or the wand seizes up for you on that day.
All you need is a total of a +1 or better on your UMD skill and you're statistically more likely to get the wand to work at least once per 24 hour period than not. Why is this? A simple rule that can help with die throws is that statistically you're more likely to roll each of the die faces over a series of rolls than to keep rolling the same die face. Thus with a 20 sided die, out of 20 rolls, only one of them should be expected to be a 1 result, likewise one of the results can reasonably be expected to be a 20.
So, for each +1 you have in UMD, the greater your chance of getting a result that would trigger the wand, rather than make it fizzle. If you have a +1 then out of twenty rolls you need to roll a 19 or 20 to succeed, and only a 1 to make a failure. If you happen to be one of the classes that gets UMD as a class skill (Alchemist, Bard, Rogue, Sorcerer, Summoner, Witch), putting 1 rank in it will also yield you a +3 bonus. Assuming you didn't dump Charisma you'd end up with a +4 bonus. That means you need to roll a 16, 17, 18, 19 or 20 on any roll as you tap tap tap away. The chances of hitting one of those numbers, versus an outright 1, are vastly greater.
WHAT BLING CAN I GET?
So you really want to UMD? You might want to consider a bit of magical bling beyond the Ioun stone. The cheapest way of pumping up your UMD check is to get a Circlet of Persuasion and gives you a +3 bonus to Charisma checks. It costs 4500gp, so the earliest you could get it, barring finding it in a module, would be to ace your faction missions for nine modules and then have the gold saved up to grab it.
As an alternative, you can pick the circlet up to offset the +3 from another sources, such as not taking one of the feats, or having a Charisma of 14 rather than 20. That way you can rock out UMD while still doing something else in a very awesome way.
While there is nothing clearly detailed in the rules about having a masterwork item to help with UMD tests, in theory such an item could exist, and is even encouraged by the system's lead designer as stated here. So if you want to squeeze a bit more out of your UMD tests, or are one of those fighters who dumped Charisma down into socially inept zone, then having a magic booklet that gives some pointers might be worth trying to find in fantasyland.
Use Magic Device is a quirky skill that potentially allows you to do basically anything in the game. The drawback is that you have to heavily invest in it if you want it to be reliable because the challenge ratings on the skill checks are very high. Further, you generally have to spend a lot of your own gold to make regular use out of the skill, which means careful planning of expenses and paying attention to how much prestige points you have before you can pick up that next fancy high level wand.
Because of the above, I'd say this is an “advanced feature” of the game. You have to have the right character build, monitor your spending, plan for the future and also become well versed in the wide range of actions that the UMD skill allows (I only covered Wands and Scrolls in this article, it can do even more odd stuff). So if you aren't interested in fussing over details, then UMD probably isn't for you.
I did want to highlight UMD for everyone though because it is the ultimate expression of “If you have the tools, you have the talent,” though on a fluffy technical level with UMD it is “If you have the talent, you have the tools.” Still, if you want to feel like Batman with his utility belt, but don't want to play a Wizard then jacking up your UMD will give you the satisfaction of always being able to pull something out to solve a situation.
That's it folks! UMD can offer up a lot of odd and surprising effects in the game. If you're willing to dive into the nuances then you'll find many rewards.
If you have the tools, you have the talent!
- Neil Carr