JG, I appreciate you taking the time to elaborate on your thoughts here on the thread. I hope you didn't take my post as a flame; it wasn't intended that way. I did use the word "curiosity" as soon as possible and ended with a reference to me possibly having "missed something". I wasn't being sarcastic. I've been working on my game today and thinking about the points you raised. Unfortunately though, I haven't been able to reply until now.
I see what you're talking about. I suppose D&D is more vulnerable to the problem than other game systems (that I'm aware of), especially with templates and advanced versions of beasties. Thanks. You've given me good game-food for thought today.
I share other posters' lack of confidence in a Knowledge skill solution.
It seems to me that this whole issue is at least as much a test of a DM's skill - not only in designing an encounter but in the way it is staged or presented - as it is a test of the players' ability to trust in the DM and to play in character as much as possible. Scanning back over the posts, I think Victim sums it up with, "Once a certain threshold is crossed, there is usually no clear distinction between the tough fight that the characters can win, and the fight that they need to run from."
I'm no 3E expert but is this always the case, "once a certain threshold is crossed"? To my mind, the encounter the players' characters should run from is one the players know their characters should run from, allowing the encounter to take on the dynamic of successful resolution being measured by survival (players keeping their wits and making use of the escape hatch their trustworthy DM has presented them).
If the encounter is one the players' characters believe they could win, they should have a chance of doing so. There is the "difficult-if-handled-incorrectly" class of encounter.
If the DM has prepared an encounter he knows the characters would think they could overcome when in fact they couldn't possibly do so (because beastie x has n levels of sorcerer up its sleeve or whatever) and there's no clue to the players that something is unusual, that's a bad encounter.
Players should believe three things: if they are stupid, they should die. If they are unlucky, they may die. If they can't trust their DM, they should get another game; they will not be punished for thinking in character (which doesn't mean to say that they won't die).
All right, there has to be a hint of metagame. There is a tacit agreement between the DM and the players that the game is going to last longer than the time it took them to roll up their characters. Is that so different from the unspoken agreement with film maker and audience that the star of the movie isn't going to be dispatched in the opening scene?
All of this, may I add, is my own insignificant opinion. I apologise if any of it strikes anyone as anything dogmatic.
I'll keep an eye on how my players react to encounters over time and bear posters' comments here in mind every time I work on an encounter. I just hope that, at some point, one of their characters says, "I don't like the smell of this. We should leave." And she's right. Then if everyone else disagrees with her, I can do a TPK and claim it was all their fault.
As if I'd do such a thing...