Blog of Holding has a post considering how 5E Divination magic might be used against PCs by villainous organizations. I thought it would be fun to try and do something similar, but for Pathfinder. Before I jump into the spells, I want to discuss one of the best pieces of system-neutral advice in the article. As GMs we know everything, but our villains don't. How do we split villain knowledge from GM knowledge? It suggests that the GM set a phone alarm for some period of time into the session, say an hour. That's when the opposing forces are casting the divination spells against the PCs. That helps you as the GM ensure that the villains are learning specific information about the PCs as well as exactly what information the villains are learning. If it happens to be when the PCs are plotting their next move, all the better for your NPCs. If not, well, sometimes you tune in the divination spell when people are just complaining about sore feet.
I'm also up on divination spells because my PCs never use them. I think after such spells have been deployed against the PCs, they're apt to become much bigger fans of using the spells themselves. Of course, this raises the same issue: what are the villains doing when the PCs tune in? There's more than dealing with random chance here--the GM has a need to balance reality with dramatic needs. At first I considered trying something like writing out basic schedules for villains, but that gets tedious fast and doesn't provide much use beyond planning for a contingency in case the party tries something--maybe. Finding that sweet spot between what the players could find out and what the players should find out is a challenge. Reward them for being inventive, but don't give the game away. It's going to be tough and I suspect it's just a matter of erring a little bit on both sides until hitting the right place.
Note: I'm doing spells from the Core Rulebook and I'm going to skip those that don't appear to have utility, like Know Direction, or those that are obvious, like See Invisibility. Spells are listed under the lowest level they can be known--except for paladin spells, because I hate paladins.
Detect Magic (bard 0, cleric 0, druid 0, sorcerer/wizard 0): Everybody knows this spell, but it's limited to 60 ft. If the bad guys have an idea that the PCs have a particular magical item or if magic is rare and the bad guys can discern the party's identity by figuring out who has access to any magic, this could be really useful.
Comprehend Languages (bard 1, cleric 1, sorcerer/wizard 1): If the campaign is taking place in a large city, this spell might not just be useful--it might be necessary. One of my campaign ideas on Golarion involves a Lirgeni diaspora community that's settled in Magnimar now that Lirgen is part of the Sodden Lands. In my Golarion, Lirgeni is also a distinct language and it's spoken heavily in their insular community--older and more insular individuals might not even speak Taldane. Bringing languages into the campaign means that this spell becomes more important. Also keep in mind that comprehend languages only allows a caster to read/understand the language. The caster cannot speak or write the language without casting tongues. (Note: this can be just as useful for creating difficulties for PCs).
Detect Animals or Plants (druid 1, ranger 1): I'm a little lost on this one--suspect it's probably highly situational.
Detect Evil/Good/Chaos/Law (cleric 1): If the PCs are alignment outliers in an a settlement, even a first level cleric should be able to find them pretty easily. And if the PCs' actions indicate their alignments' are outliers, the bad guys know to look. In an evil temple city, good PCs will shine like beacons. This isn't very helpful for low-level parties, unless they have clerics, warpriests, or paladins in them. This is wonderful for getting back at the paladin PC that's always using detect evil on every NPC. Finally, there's no save so absent actively using spells to foil it, the PCs are in for quite the surprise.
Detect Secret Doors (bard 1, sorcerer/wizard 1): Want to change things up a little? Try letting the enemies invade the PCs' hideout/fortress! Admittedly, this isn't going to be useful until the bad guys have located the PCs, but it could be a lifesaver once they have. Is the PCs' treasure room hidden? Not anymore. After ascertaining his patrol safely has the run of the place, a caster using this spell can cast this spell once and travel over the entire structure while maintaining concentration.
Detect Undead (cleric 1, paladin 1, sorcerer/wizard 1): Unless the PCs are in the habit of animating things, this might not seem useful at first. But, what if the PCs are going up against a necromancer in his own fortress? Casting detect undead could be used in the negative. Is the villain detecting undead to the north, east, and west approaches to his location? PCs must be coming from the south then--that's where the undead used to be but aren't anymore.
Identify (bard 1, sorcerer/wizard 1): See detect magic above.
Speak with Animals (bard 3, druid 1, ranger 1): I sure hope you didn't piss off a druid. Matched with a few wild empathy checks and a druid has a ready source of information. Worse, if the druid is following you, a combination of wild empathy checks and this spell results in the party being tailed far more effectively than the druid might be able to do alone.
True Strike (sorcerer/wizard 1): You've finally come face to face with your nemeses, the PCs. You've used divination magic to learn everything you can about them. You know that you've got to use that spell that requires a successful touch attack to really knock one of them out of commission. Cast this right before or in the first round of combat to make sure that spell comes off as it should.
Augury (cleric 2): This spell's effectiveness is going to be situational. But, I imagine it could be useful for villains planning on how to react to PCs that will reach them soon or for taking actions that will help them go from knowing there are general forces out there trying to foil their evil machinations to specific individuals that can be the target of further divinations.
Detect Thoughts (bard 2, sorcerer/wizard 2): With 18 seconds of concentration, a caster can identify the surface thoughts of a target that fails a will save. Once the authorities have someone in hand, this is a handy spell to determine if you've got the right party at all. Honest governments may not employ this at all, depending on how divination is viewed in society. Most will though--at least for serious crimes and searches. Villains with access to this spell won't hesitate to use it.
Locate Object (bard 2, cleric 3, sorcerer/wizard 2): At minimum, this spell is available to a 3rd level wizard that will have a range of 520 ft. (1/10 mile) when casting it. Bards get this spell at 4th level (560 ft.) and clerics get it at 5th level (600 ft.). There are some limitations though--the caster needs to have seen a specific item first hand and it can be foiled by a thin sheet of lead, polymorph any object, or nondetection. That said, if the bad guys know that the party has made off with a specific item and the party hasn't left the dungeon/fortress/etc. where the item was hidden, this is a great tool for the bad guys to follow them. If the opposing forces also happen to live in the fortress/dungeon, they likely know their way around. Even just knowing the general direction to an object could provide them with information very useful for ambushing the party later.
Speak with Plants (bard 4, druid 3, ranger 2): See notes on speak with animals above. Remember that there are ranger and druid archetypes that allow wild empathy, but with plants. If the party has pissed off a druid that can use wild empathy on the plants in a forest, their chances of hiding are nil.
Tongues (bard 2, cleric 4, sorcerer/wizard 3): Same issues as comprehend languages above. Except tongues allows the speaker to actually communicate in the language.
Arcane Sight (sorcerer/wizard 3): See notes on detect magic, above.
Clairaudience/Clairvoyance (bard 3, sorcerer/wizard 3): Now we are getting into some really useful abilities. Bards aren't going to have access to this spell until level 7, but wizards are going to have it at level 5. If the bad guys can get close enough to the party (about 500 feet), they can get a good idea of what they are up against early. If the party is entering a villain's lair, this should be de rigeur--the villain knows that she might have to deal with the party directly so she casts this spell. After observing the party, she knows exactly how she should prepare herself--as well as how she might counteract any buffs the party has placed on itself.
Helping Hand (cleric 3): So, technically, this is an evocation spell because it creates a hand out of force. But, the effects are so tied into divination that I'm (right now) house ruling it as divination. How awesome would it be for the villain to use the helping hand to lead the PCs either into a trap or right to her? Mysterious hand appears and beckons to the party? "Guys, we should follow it!" And let's see exactly where it leads...
Scrying (bard 3, cleric 5, druid 4, sorcerer/wizard 4): Why would a bard ever learn clauraudience/clairvoyance if he could have scrying at the same level--well, I guess to avoid having to deal with the will save. This is the big daddy. At this point a caster with an idea of who she's dealing with can spend 7-9 minutes observing the party. There's no distance requirement and through repeated castings even someone that's not aware of who exactly they are dealing with can get an idea. Once you've tuned in, the ability to use basic detect spells and message through the scrying can be effective indeed. A bard or wizard is going to have roughly a 1 in 3 chance of getting this off as soon as he can scry. A sorcerer, cleric, or druid is going to have even better chances. Imagine the fear you can create in your PCs at camp one night. The scry works and the villain gets their time listening in. At the very end, a message comes through, "We're coming for you."
Speak with Dead (cleric 3): This one is pretty obvious. Did the PCs take out the villain's lieutenant? After casting this spell, the villain has learned a lot more about the PCs than they'd ever want her to.
Arcane Eye (sorcerer/wizard 4): Basically no save here and unless the PCs can see invisible objects they won't know they are being observed. You can't send the eye through a gate, but there's nothing about dimension doors or other portals that allow it to remain on the same plane of existence as its caster. Great way to get the results of scrying without the possibility of failing the saving throw.
Commune with Nature (ranger 4, druid 5): Once you know generally where the PCs are, you get there, you villain, you! Then, learn how best to use their surroundings against them. Pits, falling boulders, chasms, the possibilities are endless!
Detect Scrying (bard 4, sorcerer/wizard 4): As mentioned, my PCs often don't use divination magic. This is the next step after they do. The PCs think they've got the jump on their opponent but want to really check things out. The villain's about to discuss his master plan and the PCs can taste victory by knowing exactly what they're up against. All of a sudden, she casts this spell. If she wins the opposed caster check, she knows exactly who's listening in on her plans!
Discern Lies (cleric 4, paladin 3): Has a will save component and only reveals what the speaker believes to be lies. Not the most useful for our villain--unless somebody else can think of some way to make it useful. Let me know in a comment!
Divination (cleric 4): Since this is basically a beefed up version of augury, the same rules apply.
Legend Lore (bard 4, sorcerer/wizard 6): PCs are level 11 or higher and hunting a villain? In 2-12 weeks, the villain can have a decent idea of what he's up against. Legendary is a loose term too. If the PCs are far from their home base, I might stick with the level 11 base. But, if they already have a reputation in the area, it's going to be lower--isn't a perk of heroism having songs written about you? To be fair, it should work the same way for villains the PCs want to listen in on. Legends are also pretty good at giving an idea of how a character or a party operates. For less than 500gp, this is a steal for getting the jump on your enemies!
Locate Creature (bard 4, sorcerer/wizard 4): This is great when the villain knows who she's chasing. The bright side here is that there is no saving throw. The downside is that the spell can be easily stopped/fooled. Running water stops it and mislead, nondetection, and polymorph spells beat it. This is probably good for when the villain knows she's chasing the PCs, but they aren't aware of it. If you're going to send parties out to search for someone, this is a great first step to send them in the right direction.
Commune (cleric 5): Any cleric that can cast this spell should be using it to get an idea of what's going on with their enemies. If the cleric is trying to do something terribly unholy and to move her deity's evil agenda forward, her deity definitely wants her to know what the forces trying to foil its plans are up to. Answers are true (to the best of the deity's ability) and there's no save.
Contact Other Plane (sorcerer/wizard 5): As commune, above, except be worried about what happens if the entity you reach isn't friendly. Sorcerers and wizards usually have better options unless they know they are contacting a friendly entity. Otherwise, avoid this.
Prying Eyes (sorcerer/wizard 5): Chasing the PCs into their redoubtable fortress or even the tavern they're hiding in? Prying eyes traveling the various halls can give you a great idea exactly where to go and find them.
True Seeing (cleric 5, druid 7, sorcerer/wizard 6): Let's just go with the implications here are pretty obvious.
Find the Path (bard 6, cleric 6, druid 6): Like so much of divination magic, this one is going to rely on how much oomph the GM is willing to put behind it. The caster can find the best route to something relatively knowable. Of course, by the time the PCs are facing enemies that can use sixth level spells, the PCs' hideout might be a well-known locale...
Scrying, Greater (bard 6, cleric 7, druid 7, sorcerer/wizard 7): With a duration of 1 hour/level and all casters being at least 13th level by the time that they cast it, the PCs can be placed under constant magical surveillance. Stop worrying about whether or not the villain tunes in at the right time and start focusing on how reliable the villain's designated scry-watching assistant is in reporting what the PCs have to say.
Vision (sorcerer/wizard 7): I haven't decided if this spell is banned from my table or also functions at bard level 6. Either way, it works like legend lore, only its faster but has a few side effects.
Discern Location (cleric 8, sorcerer/wizard 8): You find what you are looking for. No save. Unless there's a mind blank or divine intervention going on, you are going to find it. This spell also has no material component. Need to find out where your enemies are? So long as you know who they are, you also know exactly where they are.
Prying Eyes, Greater (sorcerer/wizard 8): See prying eyes above, but revel in the fact that your eyes have true seeing. Nothing is hidden from your flying spies!
Foresight (druid 9, sorcerer/wizard 9): Either cast it on yourself (never surprised and AC and save bonuses for that final combat) or use it to help you know how your most trusted lackey fares against the PCs. Probably better on yourself--you can scry to find out how your lackey does.