The effects of saving throws on mind reading

Question

A number of creatures in D&D systems (specific editions may not be necessary here, but let's use 3/3.5/3.75 for simplicity) have the ability to use spell or spell-like effects such as Detect Thoughts or Read Thoughts. Dopplegangers are a common case that come to mind. It is said that anyone targeted by these spells get a Will Save. The question is, are they aware of needing to make this save, either before or after it happens, and whether they succeed or fail?

It seems unlikely that the target should be aware if they fail - otherwise, it would deny any amount of discreetness that the mind-reader otherwise has. Perhaps, however, that is the case. What if mind-reading is always intrusive-feeling?

Should a target become aware if and only if they succeed the save? Do they then become entirely aware of what they resisted, or only vaguely aware they "something" attempted to manipulate their mind?

Perhaps the target should never be aware, regardless of if they succeed or fail? Perhaps there is no risk to the mind-reader - only setbacks and inconveniences. Dopplegangers read minds so often that it's unlikely they would be willing to risk even a 5% failure rate.

The 3rd Edition SRD seems to not directly tackle this question, and instead leaves it up to interpretation. What are your thoughts?

Answer 1

A failed save means the target has no idea that the effect has taken place. A successful save gives the target an idea that they’ve been targeted by a hostile mental effect, but beyond its hostility and the fact that they resisted it, they gain no more information (i.e. no indication of the source, the direction it came from, the nature of the attack, etc.).

From the Rules Compendium

Saving Throws

Success and Failure

A creature that successfully saves against an effect that has no obvious physical repercussions feels a hostile force or a tingle, but can’t deduce the exact nature of the attack.

Note that this is different from the original rule found on the SRD, which specified that a successful saving throw against hostile effects resulted in the tingle. The Rules Compendium drops that specifier, in favor of assuming that if you’ve saved against it, it was hostile enough to warrant the tingle.

Anyway, outside of any obvious physical repercussions, you get no indication that you have failed a saving throw; the rule above specifies that you are only aware of the attack if you succeed on the saving throw.

Answer 2

@Kryan hit the nail on the perverbial head, however, there is another aspect not yet addressed.

A sucessfull Skill: Spellcraft check of 25+spell level allows the character who made a saving throw against them to determine what the spell was.

Note that this doesn't say they are required to see the caster casting the spell only make a saving throw. Although this wording also means they dont even have to pass the saving throw we can infer that they must be aware a spell was cast in order to decide to make a check against it. Therefore if they fail the save (on this spell) they are unaware they need to make a check..but if they fail a save against say Ray of Exhaustion they know they tried to resust the spell, regardless of success, and therefore are allowed to make the check to identify the spell cast!

Answer 3

Detect Thoughts is Hostile Anyway

A creature that makes as successful save is alerted that SOMETHING happened, though they don't know from where, what, or even who did it (though it might make them uneasy or jumpy in any event). Any effect not marked (Harmless) that originates from a hostile creature is hostile, regardless of its other descriptors or its exact effects. Now, it should be noted that the Doppleganger or mind reader might not be hostile and the RAW gets all funky at that point, but if they're hostile or unfriendly in any way then yes, a successful save gets the described tingle. Note that it's typically on the defender to interpret something as hostile or not - that is to say, a rogue caught in the party wizard's fireball is perfectly free to decide it's a hostile effect despite how friendly the wizard might be, which is why you can opt to save against Harmless effects.

So, essentially, the mind reading effect does give off a sense that something wrong is happening unless the defender is willing to have their mind read or is for some reason incapable of being unwilling (such as by being asleep).