NPCs that can lie.
In every game I've played I can always rely on people, even my enemies, to tell the truth. The biggest lies I've seen in games are "Hey, help me...oh it's a trap." I want more than that. I want to have to wonder if I'm being mislead and catch people in their lies.
Maybe we could be told an enemy's weakness and have to realize that's wrong.
Maybe we have to find someone, but all his people give us wrong information
Maybe we accidentally turn in innocents to protect the true culprit.
It would feel nice not to go on autopilot and assume everyone has your best interests at heart (or are at least noble enough to tell you they plan to kill you).
I fondly remember Annah pointing me in the direction of the Alley of Dangerous Angles (the wench... How I loved her).
:D would be nice to get an encounter where an npc tricks you into an extremely lethal situation where you get cleaved into tiny meaty bits. The best part would of course come afterward, when you drag yourself out of the labyrinth and go collect some payback.
A little idea, could be satisfying ;)
+1 though I'd like the ability to see through microexpressions and body language whether someone is lying or not and not just with an ability or a spell.
Deus Ex Machina had good enough body-language expressions that I can navigate the dialogue without requiring any special powerups.
And Dragon Age 1 had some awesome moments.
Yeah, though this might not fit in the budget :-/
@Mythical Creature: I'm not sure what you are looking for, honestly.
There are /tons/ of examples where the PC lies to NPCs in Planescape: Torment, and this comes up occasionally at least in most western RPGs. As far as NPCs lying to the PC, this also comes up fairly frequently -- as stated, the first line of dialog is a plot-significant lie in PS:T, and there are lots of games where the initial premise turns out to be a lie.
However, this obviously doesn't satisfy you -- you say "...the player still gathered only truth. They were never able to lie in a way that the PC based his thinking on." I'm not sure what you are looking for here -- there are plenty of games where the PC is not only at a serious disadvantage due to "believing a lie" but is /prevented/ from acting in any other way (Melisan in BG2:TOB ring a bell?) I'm not sure what more you want than this...
As far as the NPCs "...gather information of the PC...would know about the PCs weak spots..." First of all, I've never seen dialog that even touches on the players combat capabilities at all, and I've never seen a PC having defined "weak spots" that an opponent could take advantage of /even in theory/. Even if a PC was (at the moment of some conversation occurred) "weak to fire", that would be an artifact of the players current equipment configuration, which might well change later. I also don't see how such a topic would reasonably come up in dialog anyway (NPC: "What is the type of elemental attacks are you most vulnerable to?").
I'm not sure that what you are looking for is even possible in real-life -- and I'm fairly confident that it is absolutely impossible within the confines of a game.
Mythical Creature commented
I have only played some of the mentioned games, not all of them. NPC were lying in that game. But the player still gathered only the truth. They never were able to lie in a way that the PC based his thinking on. Thus they never were able to use lying as a lethal weapon. They also never tried to lie, to gather information of the PC, which they would sell to the PCs enemies, which in turn would then know about the PCs weak spots, which they could use against him.
This may be a reflection of my playing style focussing on intelligence and wisdom stats, though.
Vampire Bloodlines had NPC"s try and use seduction and persuasion skills on you, I mean it was just dialogue and you could click whichever option, but man I just had to give Jeanette the locket on that first play through lol. Another NPC explicitly used a dominate skill on you too. Brian Mitsoda was largely responsible for that, and he is on the team! I have no doubt that this sort of stuff will be present.
I don't know how many wRPGs you've played, but like said before this is all over the place. Leaving aside Infinity stuff, even in newer games like Fallout New Vegas, Dragon Age Origins (I remember some jerks in Origins that faked being crippled war veterans and asked for donations... then alcohol and more money.) and The Witcher series have liars.
Arsene Lupin commented
Have you never played classic cRPGs?
Games like Baldur's Gate II and Planescape Torment were filled with lying NPCs.
Hell, in PST, the very first line of dialog you hear is a lie.
What I'm saying is: I don't think you'll have to worry on this point.
Could be interesting... But since players are pretty much used by now to only hearing the truth from NPC:s, you should make a point of letting the player know from the very start that people can and will lie to them.
Mythical Creature commented
I would like this implemented as well. But remember, that good liars mostly stick to the truth. They evade subjects and change things just as much as necessary. They display emotion and behavior fitting to what they say, not to the fact that they are lying or trying to avoid being spotted at lying. If spotted, they cover the lie by a little truth: They admit to lying, look remorseful, beg for forgiveness, but never admit to lying about a part of their story that the other guy didn't already figure out.
I like this idea and would hope that they'd implement it... not just once but several times, as there is more than one guy out there that doesn't have your best interests in mind. And give us the chance to catch the liar in the act, but not through some obvious dialog option that's available right away.
I like this idea a lot, but I also want my stats to be able to reveal a lie, potentially.