As opposed to my statement of things when?
I'll get into that a bit below, but the original position you had seemed to take - which could have been a misreading on my part - was that you would always make a monster's footprint
obvious to the PCs, rather than simply something that they had the
potential to find and understand.
* The bodak created to guard an evil lair was created by someone with the potential to create bodaks. Unless it happens to be the first and only bodak that someone ever created......
Sure, but how do you know he created a Bodak and not, say, some other nasty sort of undead? Or some sort of golem? Or any number of other magical guardians?
Now, a group could simply assume that any monster is capable of death attacks, and prepare accordingly - but that might get into the 'magical arms race' of having high level clerics able to cast extended chained Death Wards or whatever. For groups without that, what is the proper precautions to take? Enter the fight blind, on the possibility it might be a creature with a death gaze?
And yes, there are ways they could definitively find out... generally through, again, potent magic such as divinations. (Assuming the enemy hasn't taken precautions against that.) The options left to a more standard or level-appropriate adventuring group might involve sending in a scout - and IDing the Bodak could well result in dying to it.
* The wizard who happens to know Prismatic Spray researched it or learned it from somewhere. And, unless it happens to be the first time he's ever cast it........
Sure, there could be evidence somewhere. Maybe it is obvious - bards regularly telling tales of his magical duels, for example. Maybe it is less so - they would have to actively know his mentor in the magical arts, or find a copy of his spellbook. And maybe it is almost impossible to know - he could be a sorcerer who just learned it, or they could be in a foreign land confronting him for the first time, with no rational reason why they would have researched his spellcasting habits in advance.
That's the issue, again - there are plenty of situations where you
can come up with ways for the PCs to have access to this info... but also plenty of situations where they can't. Or rather, where the potential is there, as you desire, but it is so incredibly small as to be irrelevant.
* * Assassins can be sent out by lots of folks, but they are usually folks who have reasons to have sent out assassins. But, here's an interesting point -- assassins, unlike bodaks and wizards, are real. They really do target real people in the real world. And, while you or I might not have much of a chance were we randomly targetted for some unknowable reason, the people in the real world who are likely to be targetted by assassins really take real world precautions.
Maybe so. What precautions can PCs take? Investing in some sort of magical trick that will protect against death attacks? Again, you are getting into the magical arms race, and require some pretty serious resources or really optimized tricks to ensure that the suspicion an assassin might come after you translates to protection from the SoD.
*Tangent, because it's amusing: My group used to have a joke where everyone would constantly declare that they believed every square within 100' of them was always filled with invisible assassins, since the wording on the assassin's Death Attack said it didn't work if the target was aware of you, and so by declaring that invisible assassins were everywhere, you were safe if there happened to actually be one. I'm pretty sure that didn't actually work, but it was an entertaiing concept.*
* And, sure, there may be individual cases where the footprints are very unlikely to be found. If that makes sense within the setting -- if the footprint is "consistent and self-referential", I have no problem with that. Sometimes, unlikely to be found is what "consistent and self-referential" means!
Yeah, I think that's pretty much what we've been saying all along - some times, what is most reasonable is that the footprints
will be hard to find (if not nigh-impossible.) Perhaps the main disagreement here is simply how often that is the case - Ariosto comments that it is only in "certain corner cases" (if I'm reading him correctly), but I don't think it is nearly that rare.
Also, I mean to apologize for muddying the waters with the issue being about "PCs being at fault", since that wasn't specifically your point in the past. It was raised in the thread, and I think it does tie it, but isn't where this particularly thread unravelled from.
Rather, I believe this came up from your earlier talk that every SoD was technically a SSSSSoD, in that it was the result of many rolls and actions taken before the SoD effect was actually encountered.
That argument was rooted, strongly, in this claim that every monster has a distinct footprint which PCs could respond to. Thus, you felt that PCs reacting to the footprint and then encountering the SoD was a similar situation to PCs entering a fight with a monster, feeling the initial effects of a SSSoD, and reacting to that.
(If I've got your argument wrong at any point here, just let me know.)
Now, I'd argue that the two are somewhat different simply due to the immediacy of one compared to the other... but even if you don't consider that, I think the point doesn't hold up because, as you note, note all footprints are reliably found.
If a party goes to enter an evil wizard's lair, and there is a Bodak inside, there may be checks they could have made to know this in advance - perhaps rolling Knowledge: Nature to notice dead creatures (without a mark upon them) outside its lair, and Knowledge: Religion to realize this is the work of a Bodak.
If, however, the wizard has kept the Bodak confined inside (perhaps to ensure it is always in the presence of what it is guarding, or perhaps because being active around his lair would cause trouble for his other minions), then those checks go away.
There could still be ways to learn of its presence - notably powerful divination or the like - but those resources aren't always there. And, most importantly, the PCs don't know the immediate consequences of their actions.
If I am in a fight, and I slowly start turning to stone, I know that I have different options - do I continue to throw myself in the fight, regardless of the consequences, to try and win victory for my friends? Or do I try and focus on fighting off the petrification, even if it means the tide of battle might turn against us? I don't know the right answer, but I at least have a general idea of the question.
If there is a SoD monster floating about somewhere, and I don't yet know about it, while there may be courses of action that reveal its presence and nature, I don't know in advance what they are or the consequences of looking into them or not. So while there may be a number of checks that lead up to the fight, they aren't enlightened ones - and, thus, the SoD itself remains a SoD, despite the fact that it happens as part of an adventure in which many other checks have been made.