Something that’s cropped up a bit in recent times and had some discussion is the use of the Cleric’s ‘Turning Table” found in D&D B/X (Moldvay) and OSE, and obviously in BECMI (Mentzer) & Rules Cyclopedia as well, as a general improvisational skills/challenge/difficulty system. There’s been more talk about it of late (although reportedly its actually quite an old ‘Rules Cyclopaedia’ era hack) and here’s some info and links to people discussing it.

d4 Caltrops: RC Hacks & House Rules – Turning Undead Table

Back in 2020 the author of the d4Caltrops Blog (ktrey) was talking about “Repurposing the Cleric’s Turn Undead Matrix for resolving various other tasks like “Thief Special Abilities”. It can also be used to supplant the “Optional Ability Score Check” form of resolution for other tasks…” As an aside he had also previously discussed some time ago Rules Cyclopedia Hacks and House Rules related to Thief Special Abilities and his personal bugbears with the original system as written. Anyway you can find his more detailed discussion on repurposing the turn undead table here: RC Hacks & House Rules pg 15: Turning Undead Table.

Bandit’s Keep: OSR Skills Using Turn Undead as Inspiration

Another much more recent discussion of the same subject is from Daniel on the Bandit’s Keep YouTube channel, published in the last few days, if you prefer the video blog format:

I quite like this idea – and must confess it never occurred to us at the time – back in the early-mid 1980’s. I don’t know if I would completely replace the thieving skills table but its definitely a great option for everything else – especially items not covered by the rules or covered vaguely and where you don’t want to necessarily be making an arbitrary decision as a DM. Always intrigued to hear what others think, especially if you’ve used this concept or something similar in the past.