As I've been writing and writing (and writing) for Adventures Dark and Deep™, a thought has steadily lingered in the back of my mind. A question about the ultimate direction of the project.
Specifically, ADD could be its own, stand-alone game, thus entering a crowded field (and indeed one that's going to be getting only more crowded, especially as things like the upcoming Dungeon Crawl Classics RPG from Goodman Games see print). Or, ADD could be published as a supplement for an already-extant game (or games) such as OSRIC or Labyrinth Lord (much like the LL Advanced Edition Companion).
To date, I've been aiming for the former, so no real big changes there. Three books, followed by adventures and the usual accouterments. But if I go for the latter, then it would look like a single book, with the character classes, new spells, new rules for combat, and addenda for whatever monsters exist in the rules already (mainly consisting of a table to handle alterations to the hit dice and adding morale, if necessary).
I should point out that this is a question entirely occasioned by business concerns. Printing an entirely new rules system is a massive undertaking, requiring quite a bit of financing. Printing a supplement to an already-existing rules set is much more modest by comparison, and would allow me to get the salient points into print, even if the secondary goal of having everything consolidated back into three rulebooks is lost.
I'll go where my muse leads, of course, but would like to hear others' opinions on the question.