Was just wondering about this the other day.  If you were to exclude D&D and all the clones and offshoot clones of it, what other rpg's have a lot of modules out there for it?

MERP

Edit: and they're pretty darn good too... and they have covers by Angus McBride!

Yeah MERP.  Not only covers by Angus, but most of the modules have great cartography by Pete Fenlon.

Shadowrun in the 1st/2nd edition had a lot of modules.  The nice thing about them was, they started out having two news clips, one for success and one for failure of the run, so GMs could use those to let the players know what the corps were saying about the effects of the run.  Also, when the runs had chances for major effects, they listed options for followup runs as well as how Shadowrunners could capitalize through buying stock, etc.  Was pretty unique.

Call of Cthulhu has had quite a few over the years.

It's hard to know what's significant here due to the lopsided distribution of game popularity, but I would offer at least:

Traveller has had quite a few modules. With many third party modules.
RuneQuest and Hero Quest with many third party modules (at least in magazines)
Tunnels & Trolls (back in the day, of course most "modules" were solo adventures)

Fantasia, one of four RPGs by Matt DeMille.
It is one of those games that look and feel like AD&D - Palladium Fantasy, The Arcanum (Review and publisher homepage).
More than 50 adventures and modules appeared between 2000 and today.
It looks like an old school game but the modules have more of a "story" bend - locations don't even have maps.

Middle Earth RPG as others have mentioned.
Traveler last I knew had quite a few?
Marvel Superheroes had around 20? Some were hybrid sourcebook/modules.
Top Secret I believe had about a dozen? Maybe less.
DC Heroes had several.
Champions had several.
Shadowrun had at least a dozen?
Vampire had a batch, quite a few hybrid sourcebook/modules.
Tunnels & Trolls has as of last check over 20 solos and the whole Citybook series is a combination setting/module.
TFT had a dozen or so solos and one or two modules?
Gamma World over its span has about a dozen modules. Some are incompatible with other versions.
Nights Edge, the supernatural CP2020 setting had 9 or 10 modules.
Call of Cthulhu has at least a dozen. Some are massive!
Runequest had several. I've got 2. Believe there were at least a dozen?
Rifts whole line is essentially a bunch of sourcebook/mini-modules, as was a chunk of TMNT/After the Bomb.
Justifiers had just short of 10 I think. Some were hybrids.

Probably lots more I've forgotten or never heard of, or were more sourcebook than module.

If you add in modules from magazines then the number grows quite a bit!

I guess it kind of depends on how broad your definition of "module" is.  I was thinking of classic style adventure modules, but there is lots of campaign modules, and assorted splat-books that could be called a "module."  For example, to me, rift books weren't really modules though they might have contained adventures in them. They were more like setting and rules expansions.  There are a ton of GURPS 3rd ed books, but very few of them were adventure modules.

Almost all TSR RPGs had some modules: Star Frontiers, Conan, Indiana Jones, Top Secret, Boot Hill.

The more I think about it, it seems that modules were more popular/prevalent in the '80s and 90s than they are today - with the exception of Goodman.  I wonder why that is? Adventure modules are probably my favorite form of RPG product: short, condensed, cheap, and to the point of what characters do.  They cut out all the fluff.  You get more directly useful gaming content per page. They often give a bunch of interesting ideas that characters could interact with, but without much background or depth providing GMs with seeds to riff off of.  They were a far cry from today's glossy full-color 400 page setting/splat books that are often of marginal use at the table.

Shadowrun had something like 30 for SR1/SR2

Many of the games which have had Living Campaigns have a treasure trove of free / cheap adventures.
Shadowrun has had at least two such campaigns, Living Seattle and Shadowrun Missions.

Quote from: Dirk Remmecke;956930Fantasia, one of four RPGs by Matt DeMille.

Matt's site has LOTS of cool downloads too.

I wrote review for Fantasia in the ancient days.
https://www.rpg.net/reviews/archive/12/12068.phtml

Quote from: Madprofessor;956960The more I think about it, it seems that modules were more popular/prevalent in the '80s and 90s than they are today - with the exception of Goodman.  I wonder why that is? Adventure modules are probably my favorite form of RPG product: short, condensed, cheap, and to the point of what characters do.  They cut out all the fluff.  You get more directly useful gaming content per page. They often give a bunch of interesting ideas that characters could interact with, but without much background or depth providing GMs with seeds to riff off of.  They were a far cry from today's glossy full-color 400 page setting/splat books that are often of marginal use at the table.

Today's big books are probably preferred by publishers and many retailers. Less inventory, better margins. They also serve the needs of the not inconsiderable amount of collectors and readers ... people who don't game much, but have money to spend on hobby product.

Warhammer FRP had a bunch I think k
Pendragon had a few... I don't know if the Great Pendragon Campaign counts as a module but same idea

Most of the games I know with a lot of adventures have already been mentioned, but Deadlands Reloaded is up there as well once you look at both print and PDF options. Hellfrost has a fair number, too.

I feel like champions, with the the current bundle of holding should also be mentioned.

The person running this website is a racist who publicly advocates genocidal practices.

I am deleting my content.

I recommend you do the same.