I did it - I actually managed to finish a project. Or part of it at least.
Available for your consumption is
Book 2: Playing the Game
Into the Unknown - A 5e compatible game for OSR gaming.
This is basically the rules for 5e D&D, excluding magic, chargen and DM specific stuff packed into a mere 24 large-font pages of rules, with artwork on top. Probably could have made it into 22, if not for the 2½ pages of attribute descriptions I wanted to include.
Rule differences from 5e in this booklet:
- Harsher rules for healing
- Looser definition of long and short rest
- Dropping to 0 hp causes exhaustion
- Proficiency areas based on class and background instead of skills (this will be detailed more in Book 1 for chargen)
- Proficiency advantage
- Fighters get proficiency bonus to improvising stunts in combat
- A few optional rules for firing onto melee and succeeding at a cost
The main differences will be found in the other booklets, most notably Book 1 on chargen and Book 4 on How to GM (spells and monsters will be made simpler as well in their booklets) where you will find the inspiration from B/X more visible.