So I made this thread on rpg.net, but I thought that you guys might enjoy it as well.

Original D&D Retro Clones:

The Big Brown Book: Based off of the 3 Little Brown Books, except it uses the 1970s wargame Chainmail as a base in regards to OD&D's roots.

Delving Deeper: A game dedicated to emulating the rules and feel of 1974 D&D.

Microlite74: A minimalist, rules-light variant of Original D&D.

Swords & Wizardry: A simple and quick to learn simulacrum based off of 1974 D&D.  Available in the White Box Set (based off the 3 Little Brown Books), and Swords & Wizardry Complete (emulating the 3 LBBs, plus supplements.

Woodland Warriors: A Redwall-like RPG where players take up the roles of anthropomorphic rodents fighting to protect their homes against weasels, rats, and other predatory animals.

Swords & Wizardry Variants:

Backswords & Bucklers: An S&W variant based off of Elizabethan England.

Crypts & Things: A dark fantasy Swords & Wizardry variant.

Blood & Bullets: Old West variant, with Trailblazers, Gamblers, and other iconic archetypes.

Sabres & Witchery: Monster Hunters in 18th Century Europe.

Ancient Mysteries & Lost Treasure: A modern game of thrilling adventures among ancient ruins and far-flung civilizations (think Indiana Jones).

Stone & Wood: Set in "The Land," from The Chronicles of Thomas Covenant.

Holmes, B/X, BECMI, and Rules Cyclopedia Retro Clones:

Adventurer Conqueror King: A game where the players take the roles of adventurers who start out as inexperienced explorers, but then become barons setting up territory in the wilds, and eventually rulers.  Based off of the B/X ruleset.

B/X Companion: Intended to be the mythical 3rd Volume of the Moldvay/Cook set.

Blueholme: Currently a work in progress, this RPG is a variant of the Holmes version of Basic D&D.

Dangers & Dweomers: An "Advanced Basic" version of D&D, modeled after the Rules Cyclopedia.

Dark Dungeons: Named after the infamous Jack Chick strip, Dark Dungeons is inspired by the Dungeons & Dragons Rules Cyclopedia.

Labyrinth Lord: One of the oldest retro clones, it's a faithful adaption of 1974-1981 Original D&D.  Based off of the B/X ruleset.  Also has a Original Edition Characters, a "Player's Handbook" equivalent to the game.

Lamentations of the Flame Princess: A combination of old school D&D and weird fantasy, LotFP is a darker, grittier game with an emphasis on an unknown, dangerous world full of horror.  Modeled after the B/X ruleset.

Wizards, Warriors, & Wyrms: A Holmes Basic retroclone.

1st Edition Retro Clones:

Labyrinth Lord Advanced Edition Compendium: The Labyrinth Lord game, adapted to incorporate Advanced Dungeons & Dragons options as variant rules for it.

OSRIC: An Open Gaming variant of the 1st Edition AD&D rules, edited and streamlined for easy reference.

2nd Edition Retro Clones:

For Gold and Glory: A retro clone dedicated to simulating 2nd Edition as closely as possible.

Myth & Magic

3rd Edition Retro Clones:

Fantasycraft: A toolkit-like version of 3rd Edition, with a variety of options for character and campaign customization, notable for relatively balanced monster PCs.

Microlite20: A bare-essentials, minimalist RPG, with all the basic rules on a single sheet of paper.

Pathfinder RPG: An Open Gaming variant of 3rd Edition D&D, with tweaked races, classes, and spells, promising "improvements upon the 3.5 system."

Radiance RPG: A D20-System based game which blends D&D fantasy with a "modern age of science" and steampunk elements.

D&D Emulators and Other RPGs (RPGs which may not fit into any other category):

3d6 In Order: A Beer & Pretzels game which is named after a common method of ability score generation, 3d6 In Order has a quick and simple character generation to get playing within minutes.  Started out as a set of house rules for Swords & Wizardry, but then became its own game.

Adventures Dark & Deep: An RPG based on a "What If?" scenario if Gary Gygax never left TSR and took control of the development of 2nd Edition.

Ambition & Avarice

Balrogs & Bagginses: An RPG loosely based off of the B/X ruleset to design adventures in Tolkien's Middle Earth setting.  RPG.net thread.

Basic Fantasy Role-Playing: A free RPG which uses the d20 system of 3rd Edition, yet emulates rules-light play modeled on the classic D&D of the early 1980s.

Blood & Treasure: A retroclone which takes a little bit of everything from the first 3 editions.

Blood, Guts and Glory: Set in a post-apocalyptic Elizabethan England, this RPG combines elements from 3rd Edition D&D and Rolemaster.  Also known as Darkest Dungeons.

Burning THAC0: A game which uses the Burning Wheel ruleset to emulate old-school dungeon crawling.

Castles & Crusades: An RPG which tries to mimic the feel of 1st Edition AD&D, while incorporating some characteristics from 3rd Edition.  One of the earliest retro clones.

Dark Passages

Dungeon Crawl Classics: A game derived from OD&D and the Appendix N literature, with an emphasis on the high-lethality "fantasy Vietnam" play-style of old school gaming.

Epees & Sorcellerie: A French retro clone.  Has a combat system based off of the Chainmail war game and uses 2d6 as the primary resolution roll.

Forward to Adventure! A simple, streamlined RPG with an emphasis on fast-flowing heroics.

Flying Swordsmen: An RPG inspired by the Wuxia genre of martial arts.

Hackmaster Series: Hackmaster is a game inspired by AD&D 2nd Edition, but departed from the baseline with its own rules and tropes.  Available as Hackmaster 4th Edition (a meta-joke to the fictional 1st-3rd Editions in KoDT comic), Hackmaster Basic, and Hackmaster Advanced/5th Edition.

Heroes Against Darkness: An rpg which combines aspects D&D across the years, from Basic all the way to 4th Edition.

Mazes & Minotaurs: An RPG which takes inspiration from Greco-Roman myths and legends.

Old School Hack: A variant of the Red Box Hack.

Redbox Hack: A modified version of the Red Box, combining traditional D&D tropes with some indie game elements.

Searchers of the Unknown: A minimalist, 1 page ruleset to play D&D-style fantasy adventures.  Also has a collection of various homebrewed variants.

Shadow, Sword, & Spell: Fantasy RPG with pulp influence.

Spellcraft & Swordplay: A retroclone which goes further back than most and borrows elements from the Chainmail wargame to combine Original D&D (plus Supplement I: Greyhawk).

Stars Without Number: A retro science fiction role-playing game inspired by the OSR which uses a blend of OD&D and Traveller rulesets.

Tombs & Terrors: A retroclone inspired by Castles & Crusades.

Warriors & Warlocks: A 2nd Edition Mutants & Masterminds supplement which gives builds, alternate rules, and suggestions on how to recreate D&D-esque fantasy gaming with the ruleset.

Warrior, Rogue, & Mage: A rules-light RPG which uses 3 base stats for its ruleset, named after the iconic classes.  Respectively, they measure a character's combat prowess, stealth capabilities, and academic expertise.

Wayfarers RPG: Not necessarily intended to emulate the feel of any specific edition, Wayfarers attempts to construct a unique ruleset to simulate adventure in a D&D-esque fantasy world.

If I've missed any Retro Clones or D&D Emulators, or one of them is in the wrong category, please tell me!  Anything to help improve the list is appreciated!

Adventurer Conqueror King belongs in the "Other" category; it's decidedly its own thing.

Astonishing Swordsmen and Sorcerers of Hyperborea. One that I want to buy but am too broke to at the moment. I think it's probably a 1e clone more than anything else from what I've read about it, though it uses something else for thief skills.

For 3e, you also have the Radiance RPG, which seems to be a 3e/4e hybrid in some ways.

http://www.radiancerpg.com/

Not my cup of tea, but slickly done

Crypts and Things: A Swords and Wizardry variant that emulates the 'swords and sorcery' genre, with bits of 'weird fantasy' as well (e.g., R. E. Howard, C. A. Smith, F. Leiber, M. Moorcock).

My reason for not including Adventurer, Conqueror, King in the Other category was that I heard people say that it was based off of the B/X rules of D&D.

I'll check out the Radiance RPG later.  The thing with d20-based RPGs is that a lot of them just use the rules to create all sorts of settings.  A retro clone, in my view, is an RPG attempting to emulate the feel, rules, and themes of a certain edition of D&D.

Added Crypts & Things to the list.

No Hackmaster 4e?  It's AD&D like but departs pretty heavily.

Tombs & Terrors is kinda Castles & Crusades inspired

I reckon Old School Hack and Dungeon World go in the Others category.

Note that Crypts and Things has a much more darker tone, with a bestiary that allows for some creepy gaming.

That is a plethora of rulesets.

Whatever their preferred D&D edition, or hybrid of D&D editions, there just about has to be something for everyone by now.

Neoclassical Geek Revival? http://zzarchov.blogspot.kr/2011/12/neoclassical-geek-revival.html

Quote from: Simon W;606880Tombs & Terrors is kinda Castles & Crusades inspired

How could you not plug your own excellent S&W-based games?  There's Blood & Bullets Old West RPG (western based, with Shootists, Gamblers & Trailblazers), Sabres & Witchery (18th Century supernatural monster hunters), and Ancient Mysteries & Lost Treasures (Modern exploration & adventure).  And I just saw your Stone & Wood (Fantasy roleplaying set in "The Land", from the Chronicles of Thomas Covenant).  You're a busy guy.

Also, not Simon's, but there's Ruins and Ronin, an Asian inspired version of S&W.

Quote from: Zachary The First;606925That is a plethora of rulesets.

Whatever their preferred D&D edition, or hybrid of D&D editions, there just about has to be something for everyone by now.

Wonderful isn't it?

I would also point out Backswords & Bucklers, which is an Elizabethan-inspired variant of Swords & Wizardry.


-TGA

QuoteOriginal D&D Retro Clones:

Epees & Sorcellerie: A French retro clone.  Need more information.

It's a "what if" game in the vein of Spellcraft & Swordplay, something between Chainmail and OD&D, using 2d6 instead of d20. So it belongs in the "Other" category.

QuoteOthers (Retro Clones which don't fit into the above categories):

ELEGIA/Retro Phaze: An retro clone which combines elements of eight-bit video game rpgs and old school D&D.

From the introduction:
"Retro Phase, despite the title, is not a retro clone. It doesn't actually clone any other RPG."
And it shows: Retro Phaze and its predecessor Elegia utilize a d6 pool (roll and keep) system.