As a quick guess I would have said about 50 but it does make wonder.  I haven't been through HW in a while so I forget some of the ones that are listed.  1990 is a very limiting factor as well.

There are some companies that I would have to check their copyright date to see if they qualify.  For example Better Games which has Crimson Cutlass, Conrad's fantasy, Battle Born, Era Ten, Encounters Fantasy Scenarios, Designing Fantasy Scenarios, Encounters Sci Fi Scenarios, Designing Sci Fi Scenarios, and their superhero game.  Some small companies produced a number of books like this.

One of the other bigger markets that isn't covered so well are English language items from other countries.  From the UK, Australia and Canada there is probably a bunch: Lair of Medusa from Canada (there are another 4 or 5 from BC that come to mind but I don't own), Daemon, the 3 Beholder Supplements from the UK, etc.

Perhaps we could make a list that could be modified when other games/supplements will be added?

I checked quickly and I stopped at the F letter, and find at least 25-30 items, without foreign languages RPGs.
Only for French RPGs/Supplements, I think I have more than 100 items that would have been listed.
It is the same for German, Italian, and other countries RPGs...

oh definitely, i am just referencing frp items when i listed the appx. 200 items from the prior email. i know you have many other non-fantasy rpg items that i was not even discussing. and i am also not including tournament adventures, you are correct. it seems to me they should be included in a separate listing. Taf Enterprizes are basically nothing but numerical listings of stats.

Mars wrote:Realistically there is potentially a much larger number if you consider tournament modules that were available for sale.  I think there were a few from Ghenghis Con and probably some of the others as well.

Massconfusion modules are not listed as well