While coming up with some house rules that may eventually become a full blown retro-clone, I began to take a serious look at the classes. I quickly realized I was going to have to deal with class balance, and that there are issues with class balance in D&D that I don't have to deal with in MMOs (my day job). The first issue is individual xp charts for each class, and the second the potential for bonus xp if the character has high prime requisite (PR) scores.
I seen a lot written about unified xp charts, so I'll deal with them in another post. On the other hand, I haven't seen anyone discuss bonus xp for high PRs. This seems to be something that people tend to overlook a lot of the time. Not that they don't use it, every game I've ever been in has used it, but nobody really stops to think why this rule exists or what purpose it serves in the game.
I first questioned the idea of bonus xp for a high PR score when I saw the suggestion that there be bonus xp given based on how you rolled your stats. (sorry that I can't remember where I saw this) A straight 3d6 would get you a +15%, while the stand 4d6 drop the lowest and arrange to order gets you +0% (there were other options in between). I liked this idea, but realized that it was probably incompatible with the bonus xp from PRs.
It would seem to me that bonus xp from high PR scores is an concept that got its start with OD&D. In the original game it makes sense. High ability scores don't immediately make you much better at anything, but they allow you to advance in your class more quickly. In later editions where ability scores give you bonuses, I don't really see the need for the bonus xp. In fact it creates a situation where the character pretty much has to have those score or they will be gimped. The concept may make logical sense in that a strong person may be able to increase their melee combat skills more quickly, but from a game sense it create a power imbalance between the "haves and have nots". I think that this difference can become magnified if you are dealing with classes that already have high stat requirements to join them, making the chance of having a high enough PR score for bonus xp much smaller.
I've come to the conclusion that I am not going to use the stand bonus xp % in my game. If I was doing a straight OD&D or Swords and Wizardry game, I would include them, but I am using the -3 to +3 bonuses from B/X. Also, I will be making everyone use the same method for rolling stats, so the concept of bonus xp for the method used to generate stats won't be in the game either. By eliminating the bonus xp from my game, I am making the bookkeeping a little easier on everyone. It's a small point, but an important step in my larger plan to provide the option to remove xp from the game. But that's another post.