If you’re looking for house rules, and don’t mind going down a rabbit hole and possibly never coming back for several hours (possibly days), then you’ll b interested in the Links To Wisdom OSR House Rules Wiki. This amazing resources is maintained by Alex, who manages to keep it up to date (the latest change was marked 6-22).
The main categories that you can access at the wikiw include (as shown on the main page):
- Introduction (to the game)
- Player Character
- The Adventure
- The Encounter
- Non Player Characters
- Preparing and Running the Game (Dungeon Master Information)
- Inspirational Sources
But you can also go directly to a page that lists all of the entries called the All In One page, but through that way madness lies. There’s hundreds of entries across an immense number of sites and sources here, and it’s an incredible amazing resource that you should probably bookmark and go back to again and again.