One of the things that intrigued me with 3.5 were the rules dealing with PC's being able to play races other than the standard vanilla ones. You wanna play a Kobold Magic User, O.K.. How about a Hobgoblin Ranger or an Orcish Thief, no problem. I thought that this was the first time that the idea of monster races as PCs had been presented in an official, canonic way, via a rulebook: I was wrong.
Page 21 of the First Edition Dungeon Masters Guide has a section titled The monster as a player character. Gary Gygax stated that Dungeon Masters were “on their own” with regards to monsters as player characters. He thought that there was the impossibility of any lasting success for a monster PC. He thought that it was most logical to play a humanocentric as we were human and would be “most desirous and capable of identifying with”. He thought that most upper level leaders would be human, as they have no upper level limits. Also men would want to bring ruin upon monster PCs. I suppose it is true that if a Kobold was walking around a town, especially a frontier town, dressed in armor and carrying weapons, that he would most likely be attacked by the town militia. In any campaign that I have ever ran or played, a Gnome would be as close to a monster that a PC could play. Here's some text from the d20 SRD explaining how 3.5 deals with this topic.
“While every monster has the statistics that a player would need to play the creature as a character, most monsters are not suitable as PCs. Creatures who have an Intelligence score of 2 or lower, who have no way to communicate, or who are so different from other PCs that they disrupt the campaign should not be used. Some creatures have strange innate abilities or great physical power, and thus are questionable at best as characters (except in high-level campaigns). Monsters suitable for play have a level adjustment given in their statistics. Add a monster’s level adjustment to its Humanoids and Class Levels to get the creature’s effective character level, or ECL. Effectively, monsters with a level adjustment become multiclass character when they take class levels. A creature’s “monster class” is always a favored class, and the creature never takes XP penalties for having it”.
Other games such as GURPS Fantasy Folk have rules for playing 24 races other than human. Some of these races are quite monstrous, like Centaurs or Fishmen, but a majority of the races described are the standard fantasy genre types like dwarves and haflings. There is a very nice section dealing with creating your own monstrous PC races, which makes this supplement worth picking up.
I hope to continue to find other interesting topics as I re-read the First Edition rulebooks.