I've played a lot more 3.0/3.5 than AD&D but not as much as 4E and again was just wondering - are there any 'standard' or 'almost universally adopted' house rules to make it run smoother/better/faster/harder?
I don't think so. I think the closest you'll get to being 'universally' adopted is probably dropping XP penalties for multiclassing, or maybe ignoring the Monk/Paladin restriction on multiclassing. But even then, I'd bet only a minority of groups use those.
So anyone got useful house rules specific to 3.5?
The rules I use in my campaigns:
- At the start of the campaign, I put forward a list of books that are considered "player resources". Players may choose races, classes, spells, and items from those books largely without restriction, but they may not use anything that is not in those books. The list varies between campaigns; for my most recent campaign it was the PHB, DMG, Spell Compendium, Magic Item Compendium, Expanded Psionics Handbook (but not the races from this), and any and all 3.5e Eberron books.
- Ability scores can be generated in any one of three ways: roll 4d6-drop-lowest (standard reroll rules apply, and only if the rest of the group are there), 28-point buy (DMG costs), or a standard array of 16/15/13/12/10/8.
- Fixed hit points per level: 7 for Barbarians/Fighters/Paladins/Rangers (and any other class with a good BAB), 5 for Bards/Clerics/Druids/Monks/Rogues (and any other class with medium BAB), and 3 for Sorcerers/Wizards (and any other class with poor BAB). This includes at 1st level, but all characters get a one-off bonus of 5 hit points at 1st level.
- Ignore Favoured Classes and the Monk/Paladin multiclass restrictions. (Also, most of my campaigns do not use Prestige Classes.)
- Wizards get 4 spells per level added to their spellbooks, rather than 2. (My most recent campaign gave full access to Spell Compendium spells, for all casters. That won't be happening again. Also, I'm going to be rethinking specialist Wizards for future campaigns.)
- Pathfinder-style skills: Character don't get 4x skill points at 1st level, and can only put a max of 1 rank per level in each skill. However, if they have 1 or more ranks in a class skill, they get a one-off +3 bonus to all rolls with that skill. The old cross-class thing where spending a skill point only gave half a rank is eliminated. Synergy bonuses are also eliminated.
- Equipment can be sold at 1/5th of the stated purchase price. I then compensate by placing more (and more expensive) magical treasure - I've found that this makes it more likely the PCs will keep "cool but sub-optimal" magic items, where before they'd just be traded in for the Big Six.
- If a player isn't at the game, his character generally fades into the background, taking little part in the session. However, the character is generally still at some risk. Characters gain full XP for sessions where the player can't make it - I work under the assumption that people will attend as often as they can; missing a session is therefore punishment enough without also falling behind in XP!