Oriental Adventures is something of an anachronism now, especially since the word "oriental" is sort of taboo these days. Still, this classic work was the first to officially extend the AD&D universe to non-Occidental cultures, and may have been the first of many, except that TSR decided to go in other (non-Gary) directions.
It introduced, among other things, a whole slew of new classes, races, spells, monsters, and rules - of course the new classes were the most exciting part for most players! These new classes had powerful abilities but very high ability requirements as well - basically, rolling up a samurai was as hard as (or harder than) rolling up a monk or paladin. The new races, such as the korobokuru or the hengeyokai, had equally high ability requirements as well.
Unfortunately, Oriental Adventures probably should have been renamed "Japanese Adventures" since the work seemed to concentrate on only the Japan part ofthe Orient - note that of the 8 brand-new classes, only 1 was not from obviously Japanese sources (the Wu-Jen). Most of the new races, weapons, and so forth were also taken from Japanese sources - Chinese sources were rare, while other Asian sources were even rarer (if even existent).
In my opinion, Oriental Adventures should be revised and made more Chinese foremost - after all, China was the "center" of the Asian world, even if the Western world had been in rapture of ninjas and samurais for a while in the '70s and '80s. China also has a huge repository of mythology that could be a great resource for a revised Oriental Adventures - not to mention a great variety of weapons and armor that would be interesting to have in a campaign as well, from exploding bamboo tubes to mountain pattern armor to strange multi-bladed martial arts weapons. It seems that the author also weakened Chinese weapons (the three-piece rod does less damage than a Occidental quarterstaff, for example) while elevating Japanese weapons (such as the katana compared to a long sword).
One difficulty of a Chinese campaign is that the heroes of Chinese myth tend to have ALL powers in one - i.e., the combative skills of a warrior, the mystical skills of an ascetic, and the magical skills of a sage. Oriental Adventures did introduce a system of adding martial arts to AD&D, whereby a PC could use 1 proficiency slot to gain an improved AC and higher barehand damage; extra proficiency slots could then be used to learn special martial arts maneuvers as well, from flying kicks to distance death to levitation, in a way achieving the "sage-warrior" idea from old Chinese stories.In any case, there were some transliteration mistakes that I will mention here:
"Korobokuru" should be "koropokkur" (Ainu language) or perhaps "koropokkuru" (コロポックル)
"Kensai" should be "kensei" (劍聖)
"Shukenja" should be "shugenja" (修驗者)
Also, although not wrong exactly, all of the Chinese transliterations are in Wade-Giles Romanization; today, I would write it all in pinyin. (Some of the Chinese words in the book are so illegible that I can barely see where the author got them, though!)
One final gripe I had with the book was that the four "Common Martial Arts Styles" that were described were... Karate, Kung-Fu, Tae Kwon Do, and Jujutsu. Foremost, this list looks like the listings that one may find in a phonebook today when looking for martial arts classes (not exactly good medieval fantasy material here). Second, taekwondo does NOT belong in a medieval Asian campaign, since it only existed since April 11, 1955 when General Choi Hong-Hi (崔泓熙) named it! I suppose karate and jujutsu could be inserted into an Oriental Adventures campaign (noting that in the old days, karate was indigenous to the Ryukyu Kingdom (琉球國)), but "karate" and "jujutsu" are actually generic names for families of martial arts. (Also note that "karate" as a word is new itself; in the old days in Ryukyu, it was known as "toudi;" "karate" was a later adaptation to Japan's language and (anti-China) culture.)
The worst, of course, is "Kung Fu" - "kung fu" (in the incorrect English sense) is but an all-encompassing category containing all of the many thousands of styles of fighting that were and are practiced in China long ago and today. The differences between each style are tremendous, far surpassing the differences in karate styles or jujutsu styles. The kung fu styles are also great material for Oriental Adventures campaigns; for example, dog style specializes in prone fighting, while eagle claw specializes in grabbing and gripping techniques. New styles for role-playing are also easily devised; taken from myths and legends, there is a lot of good material to use out there!
So, in any case, in time, I will reorganize the Martial Arts Special Maneuvers section and post it (or a link to it) here!
But anyway... Yes, I have heard about the 3rd Edition reincarnation of Oriental Adventures (that apparently is getting hard to find now). Some things I liked about what I heard: the vanara race (based on Indian mythology) and fixes for some terminology (including those I mentioned above). Some things I didn't like that much: the "nezumi" race and the leaving of terms like "wu jen" in Wade-Giles Romanization.
2nd Edition didn't have its own Oriental Adventures supplement (although they did have a Monstrous Compendium Appendix for Kara-Tur), but they did have a free supplement called "Dragon Fist." I know I downloaded that years ago - but where did I save it?