One of the things that has arisen of late when working on my projects is a realization that I have more material I want to include than should be in a basic system book. Even breaking it into a player/GM/bestiary triad, there’s likely more for the player and GM books than I think is good.
This leads me to planning expansion volumes from the outset. I figure if enough folks pick a system up and use it, then the expansion would be useful. If nobody uses a system, then expansion is moot.
The project that most seems to need this approach is the most basic of the projects. There are many sub-classes that can be played in the full set of rules and I suspect that’s more than needed to learn the game and run a basic campaign. I’m looking at including two or three of the fighter sub-classes and leaving the others for expansion. For the scouts and wizards and witches, I’m looking at one each in the basic rules and others in the expansion. Same for the non-human choices – one each for the dwarf and elf ancestries.
The expansion also extends to procedures used in play. Special environment rules, for cold weather or steaming hot rain forests and the like would be in an expansion. That sort of thing.
I’m eyeballing a CC release of each book sans art, with only a version including art for sale (to cover the cost of the art). The expansions aren’t going to cost anybody extra money, in that fashion.
The other option that has crossed my mind is to break the system down into more pieces, with a characters book, a general rules book, a couple of GM books, and then a bestiary (or two).
Which seems to be most useful? I’ve systems that have taken each approach and not been bothered by either. I’m a single data point, however, and I figure hearing from other people could be useful.