In my pursuit of hassle-free gaming, I decided to switch from AD&D 1st Edition, the role-playing game I DMed and played the longest, to Basic/Expert D&D, the first role-playing game I ever DMed or played. I still use a great deal of AD&D material (spells, monsters, etc.), but the rules I am using are primarily Basic/Expert D&D, Labyrinth Lord, and some sections of the Advanced Edition Companion. One of the advanced rules I am not retaining is the separation of demi-humans and classes. Right now, in this overcomplicated world, simplicity is very appealing to me. One might even say it's a fantasy. Justifying which demi-humans can select which classes and to what levels is an activity I find tiresome and pointless. In my own house rules, there is sufficient room for tailoring any class, human or demi-human, to ensure variety. (I am not an advocate of cookie-cutter characters.)
This brings me to the subject of half-elves. As far as I can tell, the only reason for having half-elves is to allow a different combination of classes to be selected than would otherwise be possible. If, however, demi-humans are classes, what would be the benefit of being a half-elf? Is there anything intrinsic to half-elvishness that significantly differentiates it from pure elvishness or humanity? Should a half-elf be a "watered down" elf? If so, what would be the advantage of playing one? (I should mention here that level limits are not a factor in my games, as all classes are considered unlimited in potential.)
Rather than be lured into the trap of creating unnecessary rules complications (coughAD&Dcough), I am providing the following ruling for anyone who wants to play half-elves, half-orcs, or half-anythings in my games: Any character whose parents are of two different species will, for all intents and purposes, physically, mentally, and spiritually, be considered a member of the species of one of the parents. Genealogically, they will have branches of both species, but they will have the appearance, advantages, and disadvantages of only one of the species. The child of an elf and a human will always be either an elf or a human. If a random determination ever needs to be made, there is a 50% chance that a child resulting from any such union will be of either species.
If anyone has any questions about my reasoning, see Spock, Vulcan, Science Officer of the Federation starship Enterprise.