These are traditional AD&D classes, with the addition of the more recent Bard class.
Cleric: A devout follower of a deity, the cleric can heal wounds, raise the dead, and call down the wrath of the gods.
Druid: The druid is a worshiper of all things natural—a spellcaster, a friend to animals, and a skilled shapechanger.
Fighter: Brave and stalwart, the fighter is a master of all manner of arms and armor.
Monk: A student of martial arts, the monk trains his body to be his greatest weapon and defense.
Paladin: The paladin is the knight in shining armor, a devoted follower of law and good.
Ranger: A tracker and hunter, the ranger is a creature of the wild and of tracking down his favored foes.
Rogue (Thief): The rogue is a thief and a scout, an opportunist capable of delivering brutal strikes against unwary foes.
Wizard (Magic User): The wizard masters magic through constant study that gives him incredible magical power.
Bard: The bard uses skill and spell alike to bolster his allies, confound his enemies, and build upon his fame.
Subclasses and Special Classes
Classes such as Illusionist, Barbarian, etc. do not exist as explicit classes, but may be generated as variations of Wizard, Fighter, etc. at the player’s and DM’s discretion through choice (and invention) of skills and special abilities.
Multiclassing
Instead of gaining the abilities granted by the next level in your character’s current class, he can instead gain the 1st-level abilities of a new class, adding all of those abilities to his existing ones. This is known as “multiclassing.” For example, let’s say a 5th-level fighter decides to dabble in the arcane arts, and adds one level of wizard when he advances to 6th level. Such a character would have the powers and abilities of both a 5th-level fighter and a 1st-level wizard, but would still be considered a 6th-level character. (His class levels would be 5th and 1st, but his total character level is 6th.) He keeps all of his bonus feats gained from 5 levels of fighter, but can now also cast 1st-level spells and picks an arcane school. He adds all of the hit points, base attack bonuses, and saving throw bonuses from a 1st-level wizard on top of those gained from being a 5th-level fighter. Note that there are a number of effects and prerequisites that rely on a character’s level or Hit Dice. Such effects are always based on the total number of levels or Hit Dice a character possesses, not just those from one class. The exception to this is class abilities, most of which are based on the total number of class levels that a character possesses of that particular class. Multiclassing improves a character’s versatility at the expense of focus.
Class And Level Features
As a general rule, the abilities of a multiclass character are the sum of the abilities of each of the character’s classes.
Level “Character level” is a character’s total number of levels. It is used to determine when feats and ability score boosts are gained. “Class level” is a character’s level in a particular class. For a character whose levels are all in the same class, character level and class level are the same.
Hit Points A character gains hit points from each class as his or her class level increases, adding the new hit points to the previous total.
Base Attack Bonus Add the base attack bonuses acquired for each class to get the character’s base attack bonus. A resulting value of +6 or higher provides the character with multiple attacks.
Saving Throws Add the base save bonuses for each class together.
Skills If a skill is a class skill for any of a multiclass character’s classes, then character level determines a skill’s maximum rank. (The maximum rank for a class skill is 3 + character level.) If a skill is not a class skill for any of a multiclass character’s classes, the maximum rank for that skill is one-half the maximum for a class skill.
Class Features A multiclass character gets all the class features of all his or her classes but must also suffer the consequences of the special restrictions of all his or her classes. In the special case of turning undead, both clerics and experienced paladins have the same ability. If the character’s paladin level is 4th or higher, her effective turning level is her cleric level plus her paladin level minus 3. In the special case of obtaining a familiar, a wizard stacks his sorcerer and wizard levels to determine the familiar’s natural armor, Intelligence score, and special abilities.
Ability Increases A multiclass character gains ability score increases based on character level, regardless of individual class level.
Spells The character gains spells from all of his or her spellcasting classes and keeps a separate spell list for each class. If a spell’s effect is based on the class level of the caster, the player must keep track of which class’s spell list the character is casting the spell from.