This is just going to be a list for the convenience of my players, and I will update as new things occur to me. The previous gaming posts were me thinking out loud, what's in this post will be the rules changes I actually use.
1. No XP percentage bonuses for high stats. Most of the time it's a hassle, but I'm also doing it because:
2. There will be no level limits for demi-human characters, but humans get a 10% XP bonus to compensate for the advantages the demi-humans enjoy. Infravision, ability to detect secret doors, etc.
3. Since there are no level limits for demi-humans, I'm also allowing human PCs to multiclass if they do desire. This will be pretty much by the book, as that system seems well put together.
4. Alignment, as mentioned here, will be Law, Chaos, Neutral/Balance and unaligned. Casters like clerics and mages will have to pick an alignment, and their casting ability comes from their affiliation. Non-casters default to unaligned. They can choose to pledge their fealty to one of the cosmic forces, this will grant them the ability to call upon such forces for aid from time to time, but there's a quid pro quo, sometimes the PC will be required to do things that serve their alignment's wants and needs.
5. No Vancian magic, spell slots turn into mana, and a spell costs as much mana to cast as its level. For instance, a 4th level mage can traditionally cast three 1st level spells and two 2nd level spells. Under my rules, that mage gets 7 mana points. Each slot multiplies by the level of the spell. So the three 1st level spells equal 3 mana, and the two 2nd level spells equal 4 mana. No one can cast a spell of a level higher than they would have had access to before, so even if one has enough mana, they're not skilled enough to punch above their level. Yes, there will be a chart for this.
6. Also, you can also use mana to wear armor. 1 mana point per level of armor, so at 1st level, a mage has 2 mana points and is 9 AC (unarmored). The mage can either use those 2 mana for spells or they can burn one to wear something with 8 AC, and on through the levels. (I'm ripping this off from HARP since it worked pretty well).
7. Any 1HD or less intelligent "monster" is available as a PC, provided I get advanced notice that someone wants to play one, so I can slap together a conversion. So kobolds, goblins, not a problem. No, you can't play as Orcus (in this game, anyway).
8. Classes not listed in S&W Complete or the SRD are also available if I'm given advance notice to prep it for this game, as with the monster thing. I'm already porting over some as mentioned here, so if you can't find it in the SRD or the books, just let me know, and I'll deal with it. Hell, you don't even have to want to play it in particular, but if you want me to get it ready to play, drop me a line, within reason. I'm not going to come up with 30 or so alternate classes that no one's going to use.
Adventures Dark & Deep and Astonishing Swordsmen and Sorcerers of Hyperborea in particular have lots of subclasses, and ADD has subraces, too. My rule of thumb here is that anyone can play the standard 4 classes (fighter, cleric, mage, thief) without restriction, but if you want a subclass, you will have to meet the minimum ability requirements given, since those classes tend to have lots of little bonus tricks and such. Also, if you are taking one of the subclasses from ASSH, no multiclassing, because many of them are the equivalents of multiclassed characters anyway, and I don't want the headache.
While I'm at it, if you do take one of the 4 core classes, all of those get to add their level to a defining attribute:
Mages get it as additional mana.
Fighters get it as bonus to hit OR damage (pick one).
Clerics get it as a bonus for turning OR hit points healed (pick one).
Thieves get it as a to hit bonus and a damage bonus for backstabbing AFTER multipliers are figured, (double, triple, etc, as they level up) OR a +5 bonus to one of their thief abilities. So at level 1 they can add +5 to their Climb Walls, at level 2 they can add another +5 to Climb or they can add it to fine manipulation (for disarming traps and such), etc.
Subclasses and multiclassed characters don't get to add their level to anything.
9. I've changed my mind on saving throws, so unless I hear otherwise, I will be using the default single saving throw, rather than the traditional 5 category ones. I'm easy on this, though, it's trivial to switch, as the book gives both (and even includes both on the GM screen).
10. Descending AC. (Not really a houserule, but since S&W provides both, I'm marking my preference.) Players just tell me what AC they hit with the handy one-line table at the bottom of the character sheet, I'll do the rest. Players don't necessarily need to know the AC of the thing they're fighting, and descending works well that way.
11. There will be no specific skills (aside from thief abilities), instead, there will be ability checks, where you simply roll under or equal to your stat. If people do want skills, I can port over the system from Dark Dungeons which works fine. It'd be the same, roll under the stat, and skills would be a specialization. For example, if your Dexterity is 15 and you have two points in the Acrobatics skill, you'd roll under 17, rather than 15 when using it. Personally I think ability checks are sufficient, but I'm easy.
That's it for now, will update further if I need to. I'm also open to suggestions, just comment here on the blog, so I can keep everything together.