Around the time when MUDs were at their most popular, another group of fantasy game enthusiasts, players of AD&D (Advanced Dungeons and Dragons) and other tabletop roleplaying games (TTRPGs), were compiling lore, character classes, tables of items, home rules and more into small electronic manuals called 'netbooks'. They'd share their work with other players across the internet on various forums and websites, sometimes drawing the ire and the lawyerly nastygrams of a litigious TSR, so would also resort to using listservs, Usenet and ftp sites, ie. technology hardly anyone uses today.
The players developed these netbooks with titles such as The Net Guide to Trees and The Netbook of Bard Songs and The Complete Guide to Alcohol and The Book of Tricks and Traps, which were fairly on-the-nose as to what you'd find inside. (Care to guess, for example, what the The Great Net Spellbook contains?) This was in the days before RPGNow and the crush of D&D 3.0/3.5 materials when there weren't as many resources (easily? freely?) available to tabletop players. In fact many of the netbooks you'll find here have largely been superseded by the vast numbers of supplements you can find elsewhere.
Nevertheless, these netbooks might still hold historial interest for some, and provide genuine use for others.
Netbooks generally were published in either .txt or .doc format (Microsoft Word,) the latter format becoming notorious for the many viruses it spread across Windows machines. While leaving .txt files alone, I converted all Word documents into PDFs to allay any fears of malware. And except where noted with an asterisk (*), I did not edit anything. What you see is what players published before and just after the arrival of D&D 3.0 (and the OGL 1.0). Which means there's a bit of... unevenness in the depth, editing and formatting of these roleplaying manuals.
Is there anything interesting? Historians of RPGs might find value in the intro that E. Gary Gygax wrote exclusively for Unearthed Arcania (not Arcana... Arcania.) The one asterisk I mentioned above belongs to The Great Net Equipment List, a fairly extensive compilation of over 3,000 common and esoteric items (and crimes!) which includes their prices and weights. The item that'll probably excite most readers is the Tome of the Damned found below under The Dark Arts. If death's not your thing, there's drugs, drinking and demons to discover.
By the way, if you notice a bit of bias towards AD&D rules over other TTRPG systems, it's because, like today, most writers were players of D&D.
Stradh's Repository - One of the major sites to host netbooks was Stradh's Assorted AD&D Stuff. It's not been updated since 1999, but it's still online, and it also hosts mirrors of a couple of other former netbook repositories: The Great Net.Book Archive and Olik's AD&D Pages. While I've downloaded the files hosted at these sites, I've not added them to the netbooks below. Should the need arise I'll archive them here, but as Stradh's has been up for well over twenty years, I'm not worried it'll disappear anytime soon.
Handbooks for Roleplaying Games - Another site for netbooks, Alexander Forst-Rakoczy's website's been online since 1996. You'll find copies of many of the files Stradh's has and a couple titles (eg. the Highlander Netbook) I didn't see there.
John's Home Page - This site, while apparently not linked to by John himself, has been around since the 90's and was last updated in 2004. It hosts another set of copies of some of the netbooks found at Stradh's (as well as something called the Codex of Arcane, Magical and Mystical Items.)
Netbook Archive - You can download the entirety of the netbooks I've archived by clicking the header above. Note that I included a couple of items here and there that you cannot download individually, for example, a zipped HTML version of The Magic Workshop. I also left in .rtf versions of books that I converted for the web (Net Topics and The Drow Dictionary).
By the way, though it should go without saying, by hosting these files here I'm not necessarily endorsing their contents, ie. don't go grounding your beliefs or trying things out based on what you read in these tomes about alcohol, drugs, herbs, etc. Keep in mind these are all works of fiction made for fictional worlds.
Online Works - The titles listed below are ordered by topics that I thought best represented them. Click on the title to go to the named netbook. A couple of these netbooks have alternatives which I link in [brackets] next to the first link.
Note that a few netbooks share the same title though authored by different people. I indicate the differences by author if known.
AffectsMental Disorders (html)
The Complete Guide to Alcohol (Guide Creator) (pdf)
The Complete Guide to Alcohol (Thibault) (pdf)
The Complete Guide to Hygiene (pdf)
The Complete Guide to Sanity (Anon) (pdf)
The Complete Guide to Sanity (Guide Creator) (pdf)
The RPG Guide to Traits and Ages (text)
BestiariesDesert Monsters (text)
Empowered Familiars (text)
Kings of the Wild (pdf)
Linith's First Book of Monsters (text)
Mazaron's Monstrous Manual (pdf)
Net Monstrous Compendium 2nd Ed (pdf)
The Complete Netbook of Demons (pdf)
The Complete Netbook of Ghosts (pdf)
The Complete Netbook of Races (pdf)
The Complete Netbook of Undead (pdf)
The Complete Netbook of Vampires (text) [pdf]
The Demon Construction Matrix (pdf)
The Fey Constructor Matrix (pdf)
The Guide to Undead (pdf)
The Netbook of Golems and Gargoyles (pdf)
The Planescape Monstrous Compedium (pdf)
HistoryBook of Ages (text)
ItemsDwarven Magic Items (text)
Flower Powers (pdf)
Guide to Herbs for RPGs 3rd Ed (pdf)
Guide to Herbs for RPGs 5th Ed (text)
Herb Encounter List (pdf)
Netbook of Books (pdf)
Rhianne Tar-Brynns Arms and Armor.pdf (pdf)
RPG Bible - Weapons (pdf)
The AD&D Guide to Trees (pdf)
The Complete Niknak Handbook (pdf)
The Great Net Equipment List* (text)
The Mightiest Relics (pdf)
The Net Guide to Trees (text)
The Netbook of Armor (text) [pdf]
The Netbook of Items (pdf)
LanguageThe Drow Dictionary (pdf)
The Elven Language (pdf)
The Elven Phrasebook (pdf)
Thieves Cant (text)
MiscCreating Memorable Non-Player Characters (pdf)
Elf's Gamebook (text)
Glossary of Castle Terms (text)
Net Topics (pdf)
The Net Players Supplement (pdf)
The Netbook of Bard Songs (text)
The Netbook of Names (pdf)
The Netbook of Pranks (pdf)
The Netbook of Riddles (text) [pdf]
Unearthed Arcania (pdf)
PlanesComplete Guide to the Outer Planes, A More (pdf)
The Great Elemental Netbook 1 (pdf)
The Great Elemental Netbook 2 (pdf)
PlotsAdventure Sketches (html)
Making an Adventure (text)
Net Plots Book 1 (html)
Net Plots Book 2 (html)
Net Plots Book 3 (html)
Net Plots Book 4 (html)
Net Plots Book 5 (html)
Plots and Adventure Ideas (text)
ProfessionsA Treatise on Priests (text)
The Complete Net Psionics Handbook (pdf)
The Great Netbook of Classes I (pdf)
The Great Netbook of Classes II (pdf)
The Net Wizard's Handbook 3rd Ed (pdf)
The S&P Psionics NetBook (html)
ProficienciesNetbook of Nonweapon Proficiencies (pdf)
New NonWeapon Proficiencies (pdf)
The Netbook of Feats (html)
The Netbook of Proficiencies (html)
RealmsAl-Qadim NetBook (pdf)
Dark Sun Net Handbook (text)
Forgotten Realms Notebook Volume 1 (text)
Planescape Net Handbook (text)
ReligionLegends and Lore - The Phillipines (pdf)
The Great Net Pantheon (text)
The Netbook of Cults (pdf)
SpellsNet Tome of Magick (text)
Spell Library of the Archmage (pdf)
The Great Net Prayerbook (pdf)
The Great Net Spellbook (pdf)
TrapsGeneric Traps (pdf)
The Book of Tricks and Traps (html)
The Book of Tricks and Traps 2 (html)
The Trap Collection (html)
The Trap Collection 1 (pdf)
The Trap Collection 2 (pdf)
Appendix 13. The Dark ArtsThe Ancient Tome of Dark Magic (pdf)
The Complete Guide to Poisons (Thibault) (pdf)
The Complete Guide to Unlawful Carnal Knowledge (pdf)
The Netbook of Drugs (pdf)
The Netbook of Poisons (Mills) (pdf)
Tome of the Damned (pdf)
Since you made it this far...
I added this section to Grim Wheel after stumbling over a reddit thread where the original poster claimed that most TTRPG netbooks had been lost to time. While netbooks out of the 90s are definitely more difficult to find these days, ie. you have to know what you're looking for, they haven't completely vanished from the web, and my hope is by hosting a few netbooks here they should become more visible and available.
Though this is an odd topic to be adding to a site about old-style text MUDs, netbooks are something that grew alongside MUDs and which deepened the pool of information that MUD admins and builders drew from. May you find the various supplements, guides and other materials archived here useful as well.
Grim Wheel is a site dedicated to old school text gaming.
Click the links below to go from section to section of this site.
Buildcraft - Articles which discuss the craft of building on Multi-User Dungeons (MUDs).
MUD Forums - Links to offsite forums that concern themselves with all things related to Multi-User Dungeons.
MUD-Dev - Where you can find archives of the former mailing list known as "MUD-Dev", as well as a link to the newest mailing list.
Imaginary Realities - Archives of articles from the now-defunct online magazine Imaginary Realities.
MUD Listings - Websites which list the many text games still in existence.
MUD Clients - Clients which you can use to connect to an active MUD.
Netbooks - A repository of supplements for tabletop roleplaying games.
Miscellaneous - Links that do not fall easily into any other category.
Codebases - The various public codebases in existence today.
Area Archives - Areas for public codebases such as Circle, ROM and Smaug.