Gary Gygax's OD&D house rules (2005)

I suspect that this set of house rules has already appeared on every OSR / retrogaming forum, website or blog. Nevertheless, I believe that I should include it here. It's very good (almost perfect in its simplicity) set of house rules after all!

• Not using the supplements. Only the three little books.
• Ability scores rolled as best 3 out of 4d6. Arrange scores to taste.
• All PCs get 1d6 hp/level. HP rolls are rerolled on a 1.
• Fighters get +1 HP/die. All PCs get +1 HP/die if Con > 14.
• Fighters do +1 damage if Str > 14.
• Dex doesn't affect AC. (It does affect missile attack "to hit" rolls.)
• PCs started at 3rd level.
• PCs are unconscious at 0 hp. They can go as low as level +1 before death. (A 4th level fighter can be brought as low as -5 hp & just be unconscious.) A healing potion or cure spell restores them immediately.
• 1d6 for surprise. 1=1 round. 2=2 rounds. 3 or more=no surprise.
• PCs must declare actions before initiative. Casters must declare the specific spell being cast.
• 1d6 for initiative. A tie means simultaneous.
• A casting caster who loses initiative will lose his spell if hit.
• No training necessary to gain a level.
• To acquire new spells: Casters must find scrolls, spellbooks, or a friendly higher-level caster.
• Clerics don't need spellbooks. (The original books can be read to imply that they do.)
• Gary IDs most magic items immediately (charging large sums of money when they return to town to rest & recuperate for this service). (This is because the players are anxious to get back into the dungeon & don't want to bother with in-town adventures.) Potions must still be tasted to ID, though. Unusual items require a trip to the striped mage.