So in the monster section of my Companion, I was doing a little editing 'cause I realized I had made a note about POISON that the effects of a blown save did not generally equate to instant death...that a failed save could result in shaking and shivering for a few rounds (and thus perhaps allowing an opportunity for a cleric to cast neutralize poison, or for some form of anti-toxin to be administered).
I edited this because it didn't jibe with my overall idea that the Companion doesn't change the Basic and Expert set rules, but only supplements (i.e. adds to them). I'm not, for example, changing the cleric's low-level spell list or giving energy drain a saving throw. If DMs want to house rule such things, they're totally allowed to do so under the letter of Moldvay's Basic Set. It's not my place to do anything but compliment these rules (and add some extra OPTIONAL rules).
But then, as I read through the monsters in Moldvay's Basic set last night, I noticed (apparently for the first time since I didn't remember this AT ALL!) that many of the monsters with poison attacks...including the medusa and giant spiders...do have a certain period of time before poison takes effect; sometimes several ten minute turns even!
Wow...how the heck did I miss that?! I always found it bizarre in play that there was this cleric with the neutralize poison spell, and this attack form (poison) that instantly killed players...I mean, when is the spell supposed to be administered? Does it perform a kind of "raise dead" on poisoned characters? By default I usually allowed it to be case within one round of poisoning to actually neutralize the venom (I think that's what I do, anyway...it's been awhile since I can recall such a circumstance occurring in game).
Apparently, I should read my monster descriptions a little more carefully; obviously, Moldvay was a sharp guy (I don't think the Monster Manual provided "delayed" poison, but I'll have to check that later) and I, personally, do not know B/X quite as well as the back of my hand like I thought.
More on this later (perhaps).