Why ODD Rules

Gary Made Good Choices
I am of the opinion that Mr. Gygax wrote his rules for a game he saw Mr. Arneson run, or something like that, and this is our beloved LBBs. I base this opinion, educated guess if you will allow the conceit, on what I have read over the years and what I have heard from online interviews with such notables as Mr. Kask and Mr. Kuntz and maybe my own intuition. Perhaps it is safer to say, the designers of the Original Game, the White Box edition, made good choices than to say Mr. Gygax made them alone. The original authors present the game as a DIY, or at least add your own content in order to finish it out, product. They give their audience - innovative wargamers - a new way to imagine their games. One that includs fantasy elements from a number of popular sources including mythology, swords & sorcery pulp fiction and the work of Professor Tolkien.
Mr. Gygax didn't want to do all of our imagining for us. He says exactly this in his "Afterword" at the end of Vol. III, The Underworld & Wilderness Adventures. He left some things unexplained and encouraged us to make it work how we would like it to be. He gave us alternatives such as the two combat systems (Chainmail and d20). And he describes or implied a milieu that has come to be called "vanilla fantasy", a term coined to describe the setting in which the game is often played. This last design decision - to not tie the game strictly to any one setting or milieu, but rather to include enough variety drawn from numerous sources such that almost any world or milieu imagined by future players could be supported by the game with just a few alterations.
To this end, the rules are assembled in a modular fashion and White Box is famous for the ease with which it can be house ruled and adapted, added to, or altered. White Box, more than any other game I know, encourages creativity on the part of those who play it. It really is/can be the game you want it to be. Its adaptability is demonstrated by the many uses the basic system mechanics of the d20 or alternative combat system has been put to over the decades by various games derived from the Original White Box edition. Perhaps only the internal combustion gasoline engine has powered more vehicles (for fun) over the years since its invention.
White Box rules as written give us a game with a definite feel. It can be a bit of a fun park milieu with all the critters available in play at once, and often placed in close proximity without much regard for a viable overall eco system, but a distinct "feel" non-the-less. It is a low-powered and dangerous milieu, more low fantasy in scope where adventurers seek treasure and personal improvement rather than high fantasy where the fate of the world hangs on the outcome of the adventure, although it can definitely handle that scenario. There is a bit of a leaning toward humor and I think this is also the influence of Mr. Gygax.
According to gamer legend, Mr. Gygax was concerned that magic users might overpower the game if not limited in some significant way, therefore we have the system often referred to as Vancian magic which limits spell casters to a selection of spells based on a limited number of memorized spells of particular power levels. In White Box all characters start out relatively weak, but the magic user wearing no armor is perhaps the weakest of all. This is considered balancing the class in terms of the White Box paradigm.
White Box is a broad spectrum fantasy game, one of inclusion rather than limits. For inspiration we are referred to the works of R.E. Howard, Edgar Rice Burroughs, Jack Vance, Fritz Leiber, Fletcher Pratt and L. Sprague DeCamp - writers who focus on heroic adventure with a nod to humor - but really we are encouraged to go beyond the sources and imagine new worlds and new adventures. I think we are also encouraged to imagine new mechanics with which to nudge our own game in the direction we want to explore with it. Include sanity if horror is your goal, or corruption if the shadow hovers near. If simulation or realism is your goal, replace some of the more abstract elements of the game with something that seem more realistic to you.
I frequently grab ideas from the narrative games I enjoy reading and bring them to the White Box table. Rather than describe some aspect of the milieu, I frequently ask the players what that looks like, drawing on their creative imagination and sharing some of the narrative control of our collaborative story. I will ask them to describe how they take out a bad guy or to tell me one thing which happens along the journey to town?
Borrowing from the popularity of a certain space opera narrative dice system, I will sometimes roll a d6 as a way of adding boons and complications as I describe the outcome of a player's dice roll. A d6 roll of 1-2 means something good in addition to the success or failure of the PC's roll. A 3-4 on the d6 is neutral and a 5-6 means some some complication comes about in addition to their success or failure. Use of a similar d6 roll can leverage advantage or disadvantage to a situation or argument, or determine the degree of success or failure. More often than not, I prefer to run the White Box Alternative Combat system as written (without initiative) because I find it unequaled in providing a fast and furious resolution which seems in keeping with my mental concept of the nature of hand-to-hand combat...fast, furious and often deadly!