The first Shaman character class was introduced in the 2nd Edition Supplement, The Complete Shaman Handbook. It tied into the Planescape setting, but used a nonstandard spellcasting mechanic. It was not further developed (although it was briefly mentioned as the source of power of one of Ravenlofts minor Darklords on an island of terror).
The current Shaman is a character class in the Dungeons & Dragons 3.0 edition that was introduced in the Oriental Adventures campaign supplement.
The shaman in the Third Edition of the game is the new name given to the shukenja of the First Edition Oriental Adventures. (A character class called the shugenja also appears in Oriental Adventures 3.0 which is a different, though similarly spellcasting class.) The shaman is considered the oriental equivalent of the cleric, although it also shares abilities with the monk and druid classes. Like clerics, shamans derives their spells from divine energy in general and from powerful entities; they propitiate spirits of an animistic religious system rather than deities, forces, or philosophies (although deities may also exist as extremely powerful spirits). These spirits embody the domains from which shamans gain powers and ___domain spells. A few domains are identical to clerical domains listed in the Player's Handbook; some are unique to the shaman and have no direct equivalent to any clerical ___domain. Unlike a cleric, at higher levels a shaman can learn a third ___domain and prepare two ___domain spells per day for certain spell levels. In general, a shaman's spell list is more nature-oriented than the cleric's. Like the druid, it can gain an animal companion. Its attack progression is identical to a cleric's, while it has a variety of unarmed combat feats similar to the monk. The 3.5 update to the class found in Dragon Magazine issue 318 (April 2004) improves the shaman's combat prowess, such as by granting shamans the ability to inflict extra damage with their unarmed attacks, similar to those of monks.
The vanara, a monkey-like humanoid race also published in Oriental Adventures, has Shaman as its favored class.
Green Ronin Publishing released a 3.0 Shaman in The Shaman Handbook as part of their Master Class series. They cast divine spells spontaneously, like a sorcerer. The book also contains a number of Prestige Classes.