my house rules...
-Woodelf's alternate combat proficiency rules (on this forum)
-NO hit points, Damage monitor instead (a la Blue Rose from Green Ronin)
-Backgrounds (like those in Black Company, also GR).
-Feat lists as a guideline, not a hard set rule. Starting PCs usually can only select from lists of feats connected to their class, region (a la Forgotten Realms), race, or background. There are several "trained only" feats in the game.
-Customized base races, each with its own feat list.
-No NPC classes. Instead, villagers are treated as 0th level and have access to 1-2 backgrounds.
-Rules for teaching and learning (A character can't advance more than 2 levels without seeking out some form of training or mentor). These rules also describe eligible teachers, allowing PCs to teach each other or their apprentices.
-Descriptors. At 1st level, each character can choose 1-3 descriptors (depending on the clarity & depth of the background) to define their character concept more clearly. Whenever a character is in a situation which relates to the descriptor, they may roll two d20 instead of one, and take the higher roll. They also gain a +1 bonus whenever taking 10, and a +2 bonus whenever taking 20. For example, a PC might have the descriptor "cunning mastermind." Whenever the PC plans out an action in great detail with lots of twists and turns, the PC gains the above benefits. Usually no two PCs have the same descriptors.
-NO pre-set class skills. Instead, each PC chooses 8 skills at first level. Rogues generally get more through several options they have at first level IMC. These skills are considered "class skills." All other skills are considered cross-class skills, however, at 5th, 10th, 15th, and 20th levels a character may change one cross-class skill into a class skill, representing their exposure to the world.
-Revised skill system. Awareness replaces Spot, Search, and Listen. Stealth replaces Move Silently and Hide. Speak Language is actually a Cultural knowledge skill and worthwhile to take. Many new skills too, e.g. Navigation, Dowsing, Dreamspeak. A player may opt for "undefined" skills which are instead encapsulated by the character concept. So a rogue who grew up on the streets as a pickpocket is assumed to have maximum skill ranks in appropriate skills (Stealth, Sleight of Hand, Local Knowledge, etc) for their level. This more tightly binds the character to a concept, but is less paperwork and makes for some interesting player-gm discussions!
-Contacts are worked into the skill system
-BAB is mediated by a skill, not linked to level. Every 2 ranks in the Combat skill grants you a +1 bonus to attack. Combat is modified by Str or Dex, depending.
-Specialization allowed in sub-skills
-Use "Critical threat" range for skills (from Spycraft)
-GREATLY modified base classes (power-list-now-choose format), also I am working on guidelines for classless characters.
-NO alignment. Instead, we have alleigance rules (D20 modern), reputation rules, and "mission statements." Each character has a 3-5 sentence writeup about their moral codes, sacred cows, uncrossable lines, etc. Usually this revolves around some personal goal or ideal, such as a freed slave wishing to free other slaves.
-Homebrew magic system 50% done. Some PCs still use traditional spell system, but I have greatly altered the list, requiring all PCs to become specialists of a sort. Raise dead spells, wish spells, and save or die spells have been revised. Of course, damage spells had to be changed given the lack of a hit point system. Bestow curse has been replaced by individual curses too (Based on Book of Curses). Many unique spells as well.
-No arcane spell failure in armor. Instead, each arcane caster selects a taboo, which restricts their casting under certain thematic conditions. (I posted some of these on the house rules forum)
-Restrictions on multi-classing: A PC must meet specific requirements as if taking a prestige class, though generally these are much less stringent, and they increase as the PC increases in levels. So it's harder for someone who has stolen things and lied to people their whole life to become a priest than it is for a part-time thief who only pulled off a couple robberies.
-Character Direction. My players may decide the direction they want to take their PC in 3-5 sentences. Something like this would be appropriate: "Jes has always been fascinated by the sea and dreams of going on a great adventure. I would like Jes to become kidnapped by pirates only to become a pirate himself, eventually gaining the Dread Pirate prestige class. He will have his own ship, the other PCs as crew members and a wealthy king as his patron."
As a GM I do my best to weave the player's vision into the story, often with unexpected twists.
-Taking 100: Each player may "take 100" (automatic success) on a single roll based on their character direction. This does not have to be applied to their PC, but can be applied to ANY d20 roll made during the game (other PCs and NPCs included). In general, I allow this once per player per story arc (3-6 game sessions). I find it is simpler than using action points.
That's enough for now.