So, one of the things I took to heart while reading through James Malieszewski's Dwimmermount campaign over at Grognardia was the notion that it is easier to start with sparse rules and then add more subsystems than it is to cut back an existing bigger system. I originally intended to go real-hard core old school and use the original three Little Brown Books as the rules, and add from there. Alas, during character generation I found myself not comfortable enough with them to quickly and efficiently use them as in-game reference material.
Instead I found myself going to my extremely handy little hardcover of Swords & Wizardry Whitebox. I find its minimalism and digest size to be delightful, not to mention the awesome cover art, and so I have made it the "official" rules for the campaign. In other words, my players can expect the rules to work as written in there unless otherwise notified.
Most of the shared material for the campaign is being posted in a Google Docs folder, since we're playing via Google+ Hangouts (2 players in California, 4 in Texas, and 1 in Virginia), and included there is a compendium of house rules to date. I highlight any changes or additions made since the last session, and I'm planning on eventually editing any changes that become established into the Whitebox .rtf file and making a little "Fellhold Edition" for my own personal use, but we'll see.
With that foreword out of the way, here's a summary of the major house rulings so far:
Equipment Quick Start Packages
Shortly after one of my players asked for this option, I discovered that Brendan at Untimately had already made an excellent table for quickly generating starting equipment for OD&D. The only slight discrepancy here is that 1 wk of iron rations from the LBB's costs 15 GP, whereas 7 days worth of dried rations in S&WWB costs 21 GP. So, for now, I've skated around the issue by modifying the table to only provide 5 days of dried rations. Also, as you'll see below, the starting weapon assumptions of Brendan's chart have been modified, so there may be more trading out than would otherwise be suggested.
Weapon Damage by Class
Another excellent house rule I have swiped wholesale is Akrasia's Weapon Damage Chart from his blog Akratic Wizardry. For me, these rules are a great compromise between all characters doing d6 damage and having some mechanical differentiation between characters and weapons. I read somewhere an argument in favor of all characters with all weapons doing d6 damage that basically pointed out that by removing the mechanical import of weapons, you can have your Gandalfs with swords and Fafhrds with great swords and what not and not worry about whether they're the right class. Then there's the added benefit that the differences between weapons become much more flavor and player inventiveness based. Your giant greatsword may do the same damage as a dagger, but you can't swing it around in a 10 x 10 room. On the other hand, the idea that the magic user might be more useful just butchering people with a dagger than, you know, using magic, struck me as a bit off. So, this chart allows for flexibility while still providing mechanical benefit to fighting men actually fighting, without creating "objectively better weapons".
Bleeding to Death
I've adopted the suggested alternate treatment of 0 HP in S&WWB, where players are bleeding to death until they reach their level in negative hit points. I mostly did this as a concession to the fact that my players are not used to the lethality of Old School games, and because it has a long and hoary tradition in the game.
Class and Level Limits
Dwarves are the only non-human PC race in my campaign world, so I've done away with level limits, but to insure that it remains a human-dominated Swords and Sorcery feel, they are still limited to being fighting men.
New characters can take out up to 3 loans for 3d6x10 GP each if they desire. These loans will have 25% interest, compounded monthly, and are of course not from reputable lenders. When I saw this idea mentioned on Grognardia, it was too good a source of future trouble to pass up.
Experience is only earned by treasure *spent*. I'm not picky about what it's spent on (carousing, tithes, room and board, new equipment, whatever). This is to provide an incentive for players to have trouble acquiring large hoards and to keep diving back into the megadungeon for the increasing riches.
Late Game Stuff
I'm going to be setting up the campaign region using the rules from "An Echo, Resounding" so that I can bake in higher level concerns right from the get-go. Once again, I have to agree with Mr. Maliszewski that the appropriate "end game" for D&D characters is to become lords and lead armies and manage domains, not to become demi-gods who can warp the fabric of reality with their super powers. That stuff is way less interesting to me, and I feel like is the sort of thing that computer RPGs do better, whereas complex domain building and politics is something that tabletop games with a human referee still do better.