Cthulhu Dark’s rules are a li’l bit unintuitive for me so here is how I’ll try to think of them. I’m writing this mostly for my own benefit since I’ve had a li’l hard time with this ruleset. I’m not trying to change anything, this is no “Trophy Gold” or whatever, just another way to think of the rules.
Coming from the old school primer style, I’m not a fan of skill checks, so I was a li’l frustrated when I first tried running Cthulhu Dark.
Most of the checks have DC 1 anyway so you can’t fail ‘em. But roll a six and that triggers something module specific or situation specific. That’s why I think of ‘em more as encounter checks, just as how in B/X I might say “OK, breaking down that wall takes an hour, so let’s check for wandering monsters”.
The whole “you discover more of you roll higher” idea, I’m free to completely ignore that! I don’t enjoy that sort of “gradual” investigation checks. Any problems I’ve had running the game are 100% unrelated to that.
When it’s “interesting to the story if they’d fail”, the DC is random (roll a D6 “failure die” to determine it). I.e. actual danger, when in a B/X game there’d be attack matrixes or saving throws etc.
Players should make insight rolls when they and/or the character is scared. Even if only one of those two are scared, and no matter which of it, they should roll, but the player is 100% the judge. If they say that neither they nor the housewife or pilot they’re playing is scared by what’s happening in the game, that’s their call to make. It’s not really “optional” since they have to do it but since the director can’t fight ‘em on it, I think of it as “the optional check”.
However, if your insight die is the highest die in a roll, you’ve got to make an insight roll no matter how unscared you and your character are.
Since sixes trigger weird shit (see the “encounter checks” section above), if your insight die is a six, this absolutely stacks and might mean two rolls: the mandatory for having the insight die be the highest, and then if you also got scared from what crawled out of the six.
The “inevitable” nature of the ruleset, where there are no sudden deaths, just a safe, controlled, one-or-two steps at a time journey to the brink (sorta like that old Jenga game, “Dread”) might seem a li’l bit lacking in “unwanted” sudden deaths, and some of the included scenarios are a bit railroady.
So there’s a bit of a responsibility on the keeper side to prep things blorbily, to have a clear idea about “creeping horrors” and so on, but all that is as per ushe. You can spend time on that that you save by not having to make monster stats.
In a longer campaign, there one thing extra, though, on top of your normal blorb responsibilities:
When an “adventure” is done, insight resets to 1 (and you lose the “can lower insight by suppressing knowledge” ability if you’ve gained it). In a longer campaign full of intertwined mysteries like a season of True Detective or X-Files, it’s hard to see where one adventure ends and another begins, so you need to define some boundaries there. Maybe the crispest and most rock solid solution is that each case-cluster has its own unrelated insight die. If you’re working on the UFO sightings in the bay but get a clue about the Wolfman of Alcatraz, it’s your “Wolfman of Alcatraz insight” that ticks up. This is only for big intertwined campaigns though, don’t mess with it for a small campaign or a one shot or any other situation where you do have clear end states or break points where your insight could naturally reset to one.
I like Wonder & Wicknedess quite a lot and it’s a good fit for Cthulhu Dark. Don’t get the Marvels & Malisons companion book, that sucks. Your “sorcerer level” is your current Insight, you prep spells vancianly, and you can instead counter spells (as detailed in W&W) or use ‘em for “blast” a la Cthulhu Dark p 113 i.e. messing people up.