This claim about monster abilities as hidden information is already making assumptions about play which, as [MENTION=99817]chaochou[/MENTION] said, presusppose a "Mother may I" approach. I posted a fairly long reply to [MENTION=6688277]Sadras[/MENTION] about this and so refer you to that (it's around 50 posts upthread).OK, they're hidden information. Still something the DM knows and the player doesn't.
On this, I refer to [MENTION=82106]AbdulAlhazred[/MENTION]'s posts not very far upthread:Sure there's retries. How can there not be? We try the teahouse. If nothing, then half an hour later we try the teahouse again. If nothing, then leave off till sunset and try it again. [etc.]
combat is traditionally an activity where the PCs are given the widest range of options. Heck, an AD&D fighter has, basically, NO options that are defined by rules outside of combat! Inside combat he has at least 3-5 basic options at any given time, maybe considerably more, that are covered by the rules (at least to some extent).
The point is, if the DM says "no you cannot aim at the neck of the snake and cut its head off using a called shot." that is simply a rules adjudication, it isn't allowed by the rules. It might also be a 'no' to what might be considered possible under some circumstance, depending on the game, DM, etc. In any case, this isn't removing all good options from the PC, nor thwarting them from continuing on basically the same course (IE killing the monster, etc.).
I don't disagree that saying "no the sect is not in the tea house, period" is not definitively of a different character. There are plenty of other equally convenient places to search, there isn't a hard time constraint, etc.
All I will add to this is that, in fighting the Death Knight, whether or not a chosen approach works is (i) not just GM decides (assuming that this monster has some rules associated with it), and (ii) there are easily accessible options, like hit it with a magic weapon, which can achieve the goal of defeating it.Right, and I agree that "they aren't at the tea house" is not necessarily a very hard constraint. I would have to base my opinion of it on the specific scenario, what the players are expecting, how much of an obstacle this presents, etc. It could be nothing "we go to the dojo next door." It could be a monumental problem "the oracle told us we can only be victorious if we find the sect in the tea house."
There are some monsters which can come very close to "Mother may I" - eg the classics like green slime, ochre jelly, grey ooze and black puddings with essentially arbitrary lists of vulnerabilities and resistances - and as I already posted upthread there are some contexts in which even the Death Knight's immunity to fear may be an example of "Mother may I" (eg as an important aspect of play, a PC has sworn to drive away the next foe s/he encounters by sheer terror alone, and then the GM presents a Death Knight as the next foe and thus dictates the failure of the PC's oath).