As I prepare for a campaign to run, I realize that several of the things I want to do in this campaign may be shortcut by mind reading and telepathy. Unfortunately, many of the solutions to defending against this are unsatisfying, since they are inevitably either "Don't allow Mind-Reading" (which is something I won't do) or they involve making mind-reading useless by giving all the enemies protection against it. My question is this: How do I deal with the unique challenges mind reading presents without making it useless or banning it outright?
In a society built around privacy of thought, easy and consequence-free mind reading is too powerful. We need to make it either harder or have consequences, either by changing how mind reading works or how society does. Some ways of doing that:
Mind Reading is Hard
There's many ways to do this. Maybe it's hard to drill past the irrelevant surface thoughts, maybe mind reading is tiring, maybe it's hard to focus on one person and turning on the power means getting everyone's thoughts at once. I think one of the most interesting ways to make it harder is to just take into account how diverse minds are. In humans alone you have all sorts of mental and psychological disorders that affect how you think, let alone different cultures and languages. What happens if you mind read someone who thinks in a different language? Maybe you could see images, but it'd be damn hard to understand what's going on. Now add in the fact that you mind not even be mind reading someone of the same species. Need to pull information from that half-demon orc shaman? Good luck!
These things don't make mind reading impossible or useless, they just bring it more in line with other interrogation and investigation techniques.
Mind Reading is Stigmatized
"This guy knows where the dread necromancer is hiding, but he won't tell us a thing!"
"Stand back, I'm going to read his mind."
"...Out. Get out of our village. Right now."
This works best if you can't hide mind reading, like everybody you're scanning can tell or your eyes glow freaky colors or the like.
Muz pointed out that it'd be harder to find a society where this isn't the case. Imagine how you'd feel if somebody stole your diary and set up a bunch of webcams in your bathroom. Mind reading is worse.
Mind Reading is Loud
(from Keshlam) Reading a mind isn't like reading a book. It's more like forcing a person to broadcast their thoughts and tuning in. This means it's very, very hard to keep a reading secret: sensitive people nearby will be able to tell that it's happening, good readers will be able to eavesdrop on the reading, and the great ones will be able to spy on you, too. Enemy psions and psychic predators can hone in on the signal. Good luck hiding.
Mind Reading is Wrong
Maybe when somebody reads your mind you can feel them almost rip out your thoughts, leaving holes in your memory where you know something was important but now it's gone. Maybe when somebody reads your mind you feel exposed and vulnerable and terrified. Maybe when someone reads your mind you are forced to relive vast swaths of your life, leaving you perpetually unsure of whether you're back in the real world or just trapped in a memory. Whatever it is, getting read hurts and is wrong.
Mind reading is like any other temptation. It makes solving problems a lot easier, but you better think long and hard about whether it's worth the price.
Mind Reading is Dangerous
Instead of / in addition to mind reading being bad for your target, it's bad for you. Scanned memories become your own memories and if you're not careful you can lose your sense of self or think you're somebody else entirely. Your target can fight you off an leave you mentally scarred if they win. There's rumors that some criminal organizations have been training 'mindbombs', people who undergo unimaginable pain and lock up the memories. Peer into the wrong mind and you'll lose your own.
Although nominally specific to one game system, GURPS Psychic Campaigns is actually written as a toolbox of specific GM techniques that are directly useful in any game system, for anyone grappling with how to manage and run a campaign despite the unique challenges of psychic abilities.
It's extremely well thought- and laid-out, giving you several variations on how to manage psi for fun and profit. Everything from "wait a minute, why limit information?" to a dozen or so different techniques for controlling information either at the gameplay level or in-world is detailed. Example methods are: divide and distribute mystery-plot information across multiple NPCs to prevent any one giving away the secret in one use of telepathy; giving organised groups anticipating psi enemies access to psi countermeasures; build interesting limitation into the power itself (e.g., uninterrupted time in skin-to-skin contact only); weave folk awareness of psi countermeasures into your game cultures.
There are several interesting, clever ways to tailor a campaign for the presence of psychic characters without undermining their unique advantage. While it may says "GURPS" on the cover, the authors have covered the general needs of GMs planning a campaign with psychic PCs in any game system quite thoroughly. And as an $8 PDF, it's quite accessible.
There are a few options that can help with this that I've seen used.
Mind-reading is illegal, or inadmissible in court
In a society where mind-reading is possible, it is likely illegal to do without cause. Even where it is legal, it's possible that evidence gained from mind-reading is not acceptable during legal disputes, like how polygraph tests are not admissible in US court trials. By making the legal problems that mind-reading causes bad enough, you can encourage mind-readers to only do it in times of great need, reducing the amount of information they can get from it.
In-game gentleman's agreements
Perhaps mind-reading is not illegal, but is looked down upon by polite society. Players are free to use mind-reading, but if NPCs find out that they get a lot of their information through this power, they stop trusting the players as much. Think of how you would feel if someone had regular contact with you, and you knew they could read your mind whenever they wanted. By portraying NPCs as unsettled and less likely to help the mind-reading PC, you add a small cost to overusing the ability, without actually preventing its use.
Give False Info
Something that organizations do sometimes in real life is give subordinates who may be captured false information. That way, if they do get captured and are interrogated, then they can send their enemies on the wrong trail, rather than giving up real information. This only works when the people having their minds read are mooks, but it's very useful to make it so players don't always trust what their mind-reading tells them.
Occasionally mess with the information being transferred
One of the creepiest things that you can do to a mind-reading player is to have them hear the mind-readee say something like "I see you" while the mind-read is in progress. Adding unexpected and distracting input to the information gained by mind-reading is often more effective at discouraging it (or at least casting doubt on the veracity of the presented information) than actively blocking the ability.
How to embrace mind-reading
Investigation is boring and slow! It's often just a lot of nothing in disguise.
The fun secrets are the secrets you actually know. Because then you get to go and do cool stuff with those secrets. Thus, mind-reading offers you a fast track to cool decisions and dramatic conflict.
Don't be afraid to lay the bad guys' plans and motives out on the table — even if the PCs don't read their minds. Say that, within the first ten minutes of play, you find out that the assassins' syndicate wants to plunge the whole city into chaos, and they're going to murder the entire holy synod at their grand convocation tomorrow. Now what? Now a whole session thwarting assassins awaits! (Or you thwart them in 45 minutes and go on to deal with something else, like confronting whoever hired them or dealing with the political fallout of your last-minute heroics.)
If you want mysterious enemies, that's still possible. For example, perhaps the sorcerer-queen in her far-off shadow tower sends her apprentices out into the world to do her bidding, and they work through mostly clueless intermediaries. Navigating that network is still hard work, even with mind-reading. The PCs still have tons of opportunities to slowly discover her goals and personality (with a lot of room for mistakes in the process) through her works.
Your goal as a player should be to use mind-reading to engage more with the setting and situation, not less. Your goal as GM and game designer should be to set up and consistently apply a concept of telepathy that promotes that. (Not to minimize its impact on the developing story. If you can't help but want to do that at every turn, just axe telepathy altogether.)
Limitations should be awesome
As far as I'm concerned, when mind-reading sucks, it's not because players can use it to do crazy stuff. It's because they can use it to do not-very-crazy stuff in a deeply avoidant fashion. So, mind-reading should be crazy, big, important. It should be transgressive and intimate.
Brainer moves generally fall into two categories:
This emphasis on intimacy is critical for making the Brainer a character that fits into Apocalypse World and its themes:
Well-placed limits are, above all, evocative. They define a character as much as the powers do. They tempt you to push the situation to your advantage. Sometimes they tempt you to push the limits themselves (note the violation glove).
The main practical problem with mind-reading when presented as a simple ability is that it is:
That is a killer combo and difficult or impossible to balance against the normal run of abilities. Take out one of the three and you have a better chance:
Also note that there's nothing really specific to magic in this. Sherlock Holmes is also a difficult character to GM, in that the player can reasonably expect to detect lies and get someone's back-story all or most of the time. It's not a full mind-read but it's nearly as bad.
I went through this same thing. I learned that through role-playing, you can establish the grounds of an appropriate mind read spell. Let's say you and I are both casters and have just met in a pathfinder world. We meet at a bar and I cast a charm person spell on you and it fails. As a fellow caster, you have probably identified that I have tried to charm you through your spell craft (at the very least identifying that I was not casting a cantrip.)
Most people would find this offensive if not life threatening. In our world, if you are pulled over by a cop when driving, and you reach under your seat, they immediately put their shooting hand on the their gun to be ready. This is a similar scenario. Spells are available and people have access to them. People are readily aware that spells can be as dangerous as they can be helpful so it should come to no surprise that people will lash out at someone that has cast a spell at them, harmful or not. Your players shouldn't be prevented from using them, but when rules are established that some spells break the social norm, you get a lot of content you can add in the game to shape your world and your player's attitudes.
Plots Are Hard with a Mind-reader PC
The GM can give mind-reading several different limitations, but the most common ones include...
Limit Mind-reading to Surface Thoughts
Limit Mind-reading to Asking Questions
Limit Most Mind-reading to Mind-sending Instead
Establish Mechanical Limitations to Mind-reading
Have the mind-reader walk the mindscape.
This provides a number of advantages and opportunities of role-playing. Here is a basic outline. As described, this is a method that takes time. If mind-reading is instantaneous in your game, adjust as needed.
The reader declares they are reading the subject's mind. "Alright, that might/will take a bit of time (be it in-game or in-world). Let's put a pin in that and see what other people are doing during that." Do the other players want to watch and protect the bodies, checking vitals and shielding the potentially illegal or socially repugnant act from being witnessed? Or do they use the time to run errands, forage for food, or possibly run down other leads because their character does not trust mind-reading? This is opportunity ONE for the other players to contribute.
Going back to the mind-reader, describe to them the foyer of the subject's mind. Is it a hallway with doors, a library with aisles of tomes, a clearing in the woods? Maybe a soldier's mind is laid out like a standard army camp setting, while an assassin's is a dark maze of streets and alleyways. Perhaps the demon-blooded orc shaman is the dividing line between a cave mouth and raging, burning hell-scape. This allows you remove the monotony of just giving thoughts, fleshing out your characters, and flexing your DM muscles, all at the same time.
Now instead of just giving the player answers, have them look around. In the case of instantaneous reading, this allows the other player to help interpret what they find and make suggestions on where to look. If it is not instantaneous, the other players can still do this. Additionally, you can also turn the subject's mind into a mini-dungeon with traps, hazards, and defending monsters. Does the reader have the psychic chops to manifest their party members to help them? Or are they at increased risk of going it alone when they hop into something's head? With the above options, you can include other players, discourage delving too deep, and scale different people's minds, or any combination there in.
Understandably, this can be seen as a mountain of work to do, and if the player ends up not mind-reading, it would seem all for not. To that I can only say, you should encourage them to hop in, it has a lot of opportunity for a lot of fun.
I know you are looking for system-agnostic, but how you deal with it depends very much on the system and setting.
Limitations on Mind Reading
A person who can read anyone's mind easily, deeply, without detection, and with no way of stopping it simply breaks a whole lot of stories (most things with mysteries and most things involving any sort of bluff). In that case, the anwer is probably not to tell that type of story and instead tell a different type of story.
But most settings with mind reading also come with limitations. Perhaps there is high price to using mind reading. If, say, reading a mind can be done but it takes two hours of concentration with the subject in front of you and then you need to sleep shortly afterwards...well that is still extremely useful but it won't break most plots. Even in a mystery something like that is more of a way to verify you are right when you have a solid guess than a game breaker. You still need to identify the suspects and then find a way to persuade or force them to sit still for hours and then pay the price in immediate sleep so you won't do it too often.
Similarly, perhaps it can be done quickly, but comes at a high risk. For instance, in Mage: The Ascension mind reading did not require too many doubts in the mind sphere, even if you wanted to probe deeply. But all magic came with the risks associated with a botch (and some of the countermeasures discussed in the next section were in play)...
Perhaps you can only read surface thoughts but not probe deeply. Still very useful, and would break a standard poker game. But Still allows for mysteries, especially if even reading surface thoughts requires some concentration so you don't just pick up on everything automatically.
Resistance to mindreading
Perhaps there is some way for the subject to resist the mind reading. If this just prevents the other person from reading their mind, then it can still leave a lot of room for mystery if a lot of the important people have some resistance. But if it allows the subject to deliberately push false information...well now the mindreading is still a useful skill but you have to look into the subjects background as well to see if they had the ability to resist. Then you have to validate and verify what you think you have found even if you think they couldn't have pushed false information.
Perhaps mind reading comes with reprecussions if discovered. The other person may well attack if they discover it. That attack might be considered self defense under the law there.
Or perhaps it is outright illegal and if they are caught they are subject to arrest or worse. Or, if they are law enforcement themselves, perhaps it requires a warrant, which requires probably cause, which brings you back to using mind reading to verify something but you have to do a lot of the "heavy lifting" before you can legitimately use it. Or you may illegally mind read, find out what you want to know, but still have to find a way to provide it legally...
And of course, different combinations can be used from those categories.
I will give a very specific solution to the problem (shamelessly stolen from a movie).
If the BBEG knows that his adversaries are able to read his thoughts and thereby predict all of his actions, he can do the following:
Done correctly, this entirely negates the advantage of mind-reading effects, because the information to vacuum up with telepathy has been destroyed. Of course, if your players wise-up to this strategy, they could try to erase or alter the plans the BBEG made.
Mind Reading "problems"
Ultimately, I think that this comes down to a fundamental situation of "How can I avoid the player from solving every problem with a high Notice check?". Unless Mind Reading is a 100% successful method where you get all answers, it's really no different from a player doing a Sherlock Scan on an opponent, or making a Knowledge check. There are facts to be learned. There is a check to be made. Success, even critical success, does not guarantee getting all of the information. The player rolls, you give them information that you feel they ought to get for what they rolled, but it will not be everything.
Except, of course, where it does
There's an exception here, of course, for Epic levels of success. If, say, there's a DC of 25 to get information and the character has enough bonuses and rolls to get a 50, I'd argue that they can learn everything that the subject knows. But ultimately, this just becomes a matter of "How can I avoid Superman winning fistfights with muggers?", a problem which one seldom faces. Usually, they're facing challenges appropriate to their power level, so they have a decent chance of success, and modest results when they do succeed.
And here is where I cede to others
Most of the other cases have been covered by others, i.e. limited information, lack of admissibility in court, social taboos, etc. People are welcome to co-opt parts of my answer into theirs if they would like so as to avoid duplication of effort.
Lots of good answers so far. Here's my spin on the problem...
Human minds are really messy, and thinking happens on several levels at once, with parallel lines of cognition coming together to form conscious thoughts... which are only partially based in words. A large part of your conscious thought is peppered with conceptualizations and imagery based on your own personal experiences. Your concept of something is colored by your experiences, so it is unlikely that two people will think about the same thing with the exact same concepts. The same is true, albeit to a lesser degree, of words.
Worse, people tend to multi-task to a varying degree. Unless you are particularly focused on a task you'll likely have a number of other things happening at the conscious level. Once you go below the surface thoughts to the pre-conscious, subconscious and so on, it just gets worse. Memories aren't stored like video clips on YouTube, they're a tangled mass of associations and impressions. And fantasy, oh my, the fantasy element.
So the upshot of this is that reading minds might be easy for the right person, but puzzling out the meaning of what you've read is a whole other problem.
Imagine you have the ability to look into my head while I type this. I've got a bunch of stuff going on, most of it related to the text as I type. I have a branching set of alternative phrasings for each thing as I type it, a set of evaluations of what I've just typed, some of which will result in me backtracking and rewriting. My flatmate just got home from a weekend with her family, there's a dog barking next door, flatmate again borrowing my phone charger... and I'm still thinking about thinking, visualizing those pretty FMRI images, got a research paper about consciousness sitting in my pre-conscious mind stubbornly refusing to surface into details.
You get the idea.
Take the concept of the messy mind and use it to make telepathy as hard as you need it to be to strike a balance in your game. Make it take time for the telepath to sort through the wealth of information looking for the little gems of information. Bombard the telepathic character with misleading, confusing, conflicted and outright irrelevant data. Couch everything in impressions and nebulous concepts with the occasional word thrown in.
The hard part, as always, is the balance. You don't want to make it completely useless or the player feels like they've been cheated. But you don't want them to be able to walk past a random minion in the streets and find out every they ever wanted to know about Organization X.
So make it fuzzy. Make it time consuming. Make it hard to get solid details. In the end it's another way to feed information to the group. Make it medium difficult to get the simple things, difficult to find the critical game-ending data. Use it as a story tool, just like everything else the players are capable of.
And always remember that a smart person who knows his mind is being read can produce false results. A smarter person simply won't let his mind be read, by whatever means necessary. Depending on the setting that could mean only ever contacting people over the phone, or using a psi-screen helmet, or an amulet that protects from mental intrusion, or a scrambler, or... etc. In at least one story I've read the bad guys found a way to detect telepathic intrusions and blow the agent's brain with an implanted bomb. Messy, but effective if you care more about your secrets than your personnel.
Depending on the campaign, too, one thing that can help limit the effectiveness of mind reading is that you can't prove that you saw something in someone's mind.
Obviously this is more relevant in games where PCs are held accountable for their actions (like, say, a modern-day game). But even so, if the PCs read the bad guy's plan and try to get help from the authorities, the authorities' first question should be "So where's your proof?".
And here's the thing: you can't prove it. As far as some cop is concerned, there's no difference between a so-called mind reader saying "this guy is going to do this terrible thing" and a non-psychic saying the same thing. Likewise, projecting the bad guy's thoughts into a cop's mind can't prove anything because for all he knows you're generating those thoughts yourself. Things pulled from a person's mind aren't hard evidence because they're not real. They can be easily faked, or might just be an idle daydream rather than a master plan the guy's actually going to follow through on.
It's similar to how some settings (like Eberron) have things in place that say that evidence gathered by magic (be it magic spell, divine effects, or detect alignment aren't considered "legal", because they're too easy to fake and/or the only real proof of validity they have are the caster's word.
Mind reading is powerful, and due that, it should not be simple to use. For starters, you should make the player think twice when using it. Some ways it can be done.
Use requirements and restrictions: This ability has its rules.
Levels of power: When using this ability, you must choose how intensely you probe the target, the harder you push, the bigger the rewards, but the risks are also higher.
Drawbacks: Mind reading can reap many rewards for their users, but also carry many risks. Example drawbacks: