As part of my reconsideration of running Lamentations of the Flame Princess but properly rules-as-written, I of course had to muck it all up and add a bunch of house rules. To make the mental ability scores more applicable, I apply them to set categories of saves. The other major feature is a Casting Roll so magic-users and clerics are limited to a number of known spells, that may be swapped out or replaced with difficulty, but can cast them as long as they keep rolling well. I think this is both more fun at the table, as a wizard is worried about any time they cast a spell and yet could spam a bunch of spells. I ported over the sleep exhaustion rules, already present in the game, to make this complete.
Hope yall enjoy! I've already started running at my table, and the cleric casting rules and ranger are being playtested.