On a regular basis? For research? For enjoyment? To mine for ideas? To test new systems?
I have been collecting rpgs since 1975. I still have most of them. I am happy to switch between systems for each campaign I run, even nowadays. I have a huge
Ars Magica collection, a large one for
RuneQuest, a goodly amount of D20, over a dozen GURPS supplements, and over 30 other systems in one form or another.
During any given weekly session, I use maybe 1-3% of the collection. For a given campaign this probably shoots up to 5%. On the other hand when I am setting up a campaign I use large swaths of material, gleefully jumping between systems for ideas (as well as my non-gaming library). And I can say that I have read through, cover to cover, 90+% of these books (including the
Aria books...).
So this weekend for my game I will end up using
Arcana Unearthed, the
Monster Manual the
Dungeon Master's Guide, and maybe an extra book or two of spells -- just about 1% there. This is a pretty simple session. Others I might use a dozen books. And when I switch to a different system, I will use a different group (and percentage) of my books.
I use most of them, just not necessarily in the way they were intended.
