From the introduction:
A summary of my house rules for Swords & Wizardry (with appropriate links). They are intended, when used together, to simulate more closely the ‘swords and sorcery’ genre, as exemplified in the fiction of Robert E. Howard and Fritz Leiber. Nonetheless, most of these house rules can be used on their own in a ‘standard’ or ‘classic’ ‘Old School’ D&D game (including Original D&D, Basic D&D, RC D&D, Labyrinth Lord, 1e AD&D, OSRIC, etc.).