I've finally started a new campaign, set in a fantasy Europe after the Roman Empire's fall. And for the system I've found myself using Holmes basic D&D, augmented by the traditional "anything I like." Today being the anniversary of J. Eric Holmes's birth it seems only fitting to discuss the Holmes book and its legacy.
The Holmes booklet was written because the OD&D rules were impenetrable, poorly organized and difficult to learn outside of being taught the game. It condensed the D&D essentials into 48 pages, a feat that is pretty much unrepeated especially when you consider he more or less includes a dungeon module in that page count. (Even the recent simulacrum Blueholme is longer, although it's better organized.)
What's fascinating is the timing of Holmes's D&D. As I've noted before, it arrived in 1977 and described the transitional late OD&D - the game as it was played before AD&D became the dominant player on the scene. In this sense it is much more relevant to "golden age" play than the OD&D LBBs themselves, where the additions such as Greyhawk, Blackmoor and Eldritch Wizardry were eagerly integrated into most games.
The thing that's really made me fall for Holmes is its open-ended nature. Technically Holmes specifies a setup for races and classes similar to Moldvay's Basic rulebook, where Halflings, Dwarves and Elves are merged down into single classes; but it also implies that there are more possibilities. Aesthetically it's so much easier for me to hack and alter the Holmes game, since race/class are already separate, than to try and do the same with Moldvay and Cook/Marsh Expert.
In the Cook/Marsh Expert rulebook there is advice on integrating Holmes but unfortunately it's all backward. The Expert book should be used for adding the levels above 3 to Holmes, and additional spells, monsters, and magic items, and the wilderness rules that Holmes left out - but that's about the extent of what I think its utility is. Other material can be freely integrated; my current game has a ranger from the Strategic Review.
One of the most unique rules in Holmes basic is about initiative - it is assumed to be determined by Dexterity rather than rolling a d6 for each side. This actually provides a fairly unique order of battle, and allows it to proceed in a straightforward and smooth fashion, without either the uniformity of rolling for "sides" or the tedium of rolling initiative for every participant. It gives a tactical dimension with the potential for monsters to have a higher Dexterity than the PCs, and a bit of differentiation. I've come around to this and find it a refreshing change.
Holmes, for me, is the ideal basis for a "make your own" D&D, constructed from bits and pieces both new and old. As a monster aficionado, there is no limit to the number of sources I'll consult, but beyond that Holmes is such a simple framework that most sources fit into it without much effort. Clones of Holmes such as Blueholme beat it in terms of organization, but for me nothing has quite the same appeal as that simple 48-page booklet.