Some of the comments to my post on The Gray Book yesterday that The Gray Book was too much like AD&D to be considered OD&D confused me. The only reason I can think is that the 1e retroclones have given people a very limited idea of what OD&D included. Swords & Wizardry, for example, mainly emulates the original three book set of OD&D. Swords & Wizardry include the different die types for hit dice and weapons — and some of the new spells — from the first OD&D Supplement, but ignores most of the addition material in Greyhawk and seems to completely ignore the additional material in Blackmoor, Eldritch Wizardry, and the issues of The Strategic Review published in 1975 and 1976. Most OD&D campaigns played in the 1970s used a great deal of this OD&D material that currently available 0e retroclones ignore.

Here is a list of the major material added in the three OD&D supplements and in issues of The Strategic Review:

Greyhawk added:

* more bonuses and penalties for attributes, including exceptional strength for fighters and number of spells knowable per level for magic-users
* More class options for non-human characters
* Thief class
* Paladin fighter sub-class
* different die types for different weapons and class hit dice
* weapon vs armor type modifiers
* multiple monster attacks
* more spells, including levels 7-9 for magic-users and levels 6-7 for clerics
* many more magic items, including lots more miscellaneous magic items
* many more monsters (including metallic dragons)

Blackmoor added:

* Monks as a cleric subclass
* Assassins as a thief sub-class
* Hit location during melee
* new monsters (mainly aquatic)
* new magic items (mainly water related)
* underwater adventure rules
* specialists (sages)
* diseases

Eldritch Wizardry added:

* Druids as a cleric subclass
* Psionics
* Segmented melee round
* new monsters (mainly psionic monsters and demons)
* Magical Artifacts (Mainly from Greyhawk)
* new outdoor encounter tables

The Strategic Review Added

Issue #1 (Spring 1975)
* the Mind Flayer (non-psioniv version)
* Solo Dungeon creation tables

Issue #2 (Summer 1975)
* Rangers a a fighting-man subclass
* D&D FAQ explaining a number of rules poits that weren’t clear

Issue #3 (Fall 1975)
* new monsters (including cllasics like Shambling Mounds, Piercers, Lurker Above)

Issue #4 (Winter 1975)
* Illusionists as a magic-user subclass
* Ioun Stones

Issue #5 (Dec 1975)
* a few new magic items and monsters (including prayer beads and the Trapper)

Vol 2, No 1 (Feb 1976)
* Two Axis Alignment System (Law/Chaos, Good/Evil)
* Bard class

As you can see from the above list, there is a lot more to OD&D than current retroclones have elected to include. Groups that used most of these rules — and most groups I knew of in the 1970s did use much of this material — were playing a game very similar to what was later published as AD&D — just without all fine detail and complexity of that came with the longer and more detailed AD&D rules. However, the game they were playing was still OD&D.

The Gray Book includes most of the additional OD&D material published by TSR in 1975 and 1975. This makes it look more like AD&D to those unfamiliar with the OD&D supplements, but the rules are still OD&D. The lowest armor class is 9, not 10. The hit tables are those of OD&D not those of AD&D (where 20 repeats five times), there are no material components or XP costs for spells, spell and monster descriptions are usually very short, etc. Most people who played OD&D in the 1970s would look at The Gray Book and see the D&D rules they used, just in one book instead of in six booklets and six newsletters.