A character class is a fundamental part of the identity and nature of characters in the Dungeons & Dragons role-playing game. A character's capabilities, strengths, and weaknesses are largely defined by their class; choosing a class is one of the first steps a player takes to create a Dungeons & Dragons player character. A character's class affects a character's available skills and abilities. A well-rounded party of characters requires a variety of abilities offered by the classes found within the game.

Dungeons & Dragons was the first game to introduce the usage of character classes to role-playing. Many other traditional role-playing games and massively multiplayer online role-playing games have since adopted the concept as well. Dungeons & Dragons classes have generally been defined in the Player's Handbook, one of the three core rulebooks; a variety of alternate classes have also been defined in supplemental sourcebooks.

Types of classes Principal base classes These base classes have appeared as character classes in the core rulebooks of multiple editions of Dungeons & Dragons:

Barbarian Bard Cleric Druid Fighter Monk Paladin Ranger Rogue Sorcerer Warlock Wizard

Alternative base classes

While the main character classes available have remained fairly consistent since the 1st Edition of Advanced Dungeons & Dragons, a variety of alternate base classes have been offered in supplemental books. The release of Unearthed Arcana in 1985, for instance, introduced the base class of Barbarian and reworked Paladins to be a type of the new base class "Cavalier". Oriental Adventures (1985) also introduced a number of alternate classes more appropriate for an Eastern setting. The 2nd Edition added several completely new base classes (e.g. Runecaster and Shaman); in addition, supplemental handbooks offered a variety of "kits" to customize each base class, and the Dungeon Master's Guide offered rules for creating new character classes. The 3rd Edition introduced five classes for use in creating non-player characters in its Dungeon Master's Guide. v3.5 Edition introduced the Artificer as a new standalone class for the Eberron campaign setting and it has continued to appear as an alternative class in the subsequent 4th and 5th Editions.

Non-core base classes are considered optional and do not always exist in all settings. For example, the Samurai class introduced in the Oriental Adventures book may not make sense in a game set in a standard European-style realm. Similarly, classes associated with psionics such as the Psychic Warrior do not apply to worlds without psionics.

Multiclassing Most editions of Dungeons & Dragons have allowed for the possibility to either advance in more than one class simultaneously, alternately taking levels in more than one class, or branching out in a second (or more) class at a specific point defined by the first class, a concept generally called "multiclassing".

In the 1st and 2nd editions, changing a character's class is difficult. Only those playing as humans can, and it requires extremely high stats to do so. This is called "dual-classing". Non-humans, on the other hand, can "multiclass" where they effectively learn two (and rarely even three) classes at the same time at the cost of slower level progression for that character.

The 3rd edition allows players to mix and match levels from any number of classes, though certain combinations are more effective than others. In addition, Prestige classes add more options for multiclassing. This edition offers the most freedom regarding multiclassing. There are, however, penalties to the rate of experience point gained if classes are added haphazardly. The 3rd edition version of Unearthed Arcana includes rules for gestalt characters which combine the advantages of two classes.

The 4th edition allows characters to take a feat that grants access to specific facets of another class. The class-specific multiclass feats are also prerequisites for the power-swap feats, each of which allows the character to swap out a daily, encounter, or utility power from their first class for one from their second class. Also, at level 11, a character with a multiclass feat and all of the power-swap feats is eligible for paragon multiclassing, which allows them to gain additional powers from their second class in lieu of taking a Paragon Path. Some classes are only available through multiclassing; the first such class was Spellscarred, introduced in the Forgotten Realms Player's Guide. In the 4th Edition, each character can only multiclass into a single class, unless otherwise stated by their primary class (such as the Bard). The Player's Handbook III introduced "hybrid" classes, a deeper form of multiclassing in which elements of two classes are combined each level.

In the 5th edition, multiclassing requires minimum ability scores before it can be chosen; however, the requirements are not as steep as in previous editions. The core classes only require an ability score of 13 or greater in the specific requisite score, except for the Monk, Paladin and Ranger (who need 13s in two stats).

D&D original version + Original Dungeons & Dragons classesSourceClassesBook I: Men and MagicSupplement I: GreyhawkSupplement II: BlackmoorSupplement III: Eldritch Wizardry

In the original Dungeons & Dragons boxed set, there are only three main classes: the Cleric, the Fighting-Man, and the Magic-User. The first supplement, Greyhawk, added the Thief as a fourth main class, as well as the Paladin as a Fighting-Man subclass. These four fantasy gaming archetypes represent four major tactical roles in play: the Fighter offers direct combat strength and durability; the Thief offers cunning and stealth; the Cleric provides support in both combat and magic; and the Magic-User has a variety of magical powers. In many ways, other classes are thought of as alternatives that refine or combine these functions.

Each of the playable races have different amounts of access to the classes. Dwarves can be Fighters or Fighter/Thieves, with Fighter/Cleric possible for NPCs. Halflings are restricted to the Fighting Man and Thief classes. Elves are restricted to Fighter/Magic-User, Fighter/Magic-User/Thief, and Thief class options, with Fighter/Magic-User/Cleric an option for elven NPCs. Half-Elves (introduced in Greyhawk) can be Fighter/Magic-Users, Fighter/Magic-User/Clerics, or Thieves. All four non-human races have limited level advancement except in the Thief class. Humans can be any single class with no level restriction.

AD&D 1st edition +1st Edition classesClassSub-classesPlayer's HandbookBard*—ClericDruidFighterMagic-UserIllusionistMonk—ThiefAssassinUnearthed ArcanaCavalierPaladin (variant)(Fighter)Barbarian(Thief)Acrobat*Oriental Adventures(Cavalier)Samurai(Cleric)(Fighter)(Magic-user)Wu JenMonk (variant)–(Thief)Dragonlance Adventures(Cavalier)Tinker―Wizard of High Sorcery(Cleric)* Cannot start at 1st level; functions like a prestige class in later editions.

Advanced Dungeons & Dragons loosened the restrictions on race and class combinations, although non-human races often have restricted choices among classes and maximum levels they can reach in a class. Additional classes that had first appeared in supplements and articles in The Strategic Review magazine are included as base classes. The Player's Handbook also introduced the bard as a sixth class; however, its usage in first edition is more akin to what would be called a prestige class in later editions, as it was not a legal choice for a starting character. Instead, a character has to start as a fighter, change classes to a thief, and finally switch classes once more to become a bard.

A character's ability scores directly tie into what class choices are legal for them. For instance, a character wishing to be a fighter requires at least 9 strength; the more discriminating monk requires 15 strength, 15 wisdom, 15 dexterity, and 11 constitution. Unusually high or low ability scores can proscribe class choice further; "too high" an intelligence can prohibit being a fighter, while a charisma of 5 or less will require the character to become an assassin. High ability scores in statistics considered pertinent to the class will grant an experience bonus.

The Player's Handbook brought about other changes in the game and its character classes. Fighters, clerics, and thieves have increased hit dice compared to the original edition. The book also made changes to how the strength score of a character affects their chances to hit in combat and cause damage, as well as how much weight they can carry, and the roll to open doors successfully. A higher intelligence score grants an increased chance for both knowledge of spells and ability to learn languages. A higher wisdom score grants clerics a bonus to their spells, while low wisdom imposes a possibility that their spells will fail. New charts detail the effects of the constitution, dexterity, and charisma scores for characters. Each of the five main character classes and five sub-classes have its own table for charting gains on experience points; for most of these classes it now required more experience points than before to reach beyond third or fourth levels. The book also introduced multiclassed characters to the game.

Unearthed Arcana added the Cavalier, Barbarian, and Thief-Acrobat classes.

D&D Basic Set +Dungeons & Dragons Basic Set classes Category ClassesHuman classesDemi-human classesHigh-level classes* Introduced in supplemental rules. The second version of the Dungeons & Dragons Basic Set combines the idea of race and class; non-human races do not have classes. Hence, a character might be a (human) Cleric or else simply an "Elf" or "Dwarf". The Basic Set presented four human classes: Cleric, Fighter, Magic User, and Thief, and three demi-human classes: Dwarf, Elf, and Halfling. The Companion Set introduced four optional classes for high-level characters: the Avenger, Paladin, and Knight for Fighters, and the Druid for Clerics. The Master Set introduced one additional class: the Mystic. The Rules Cyclopedia includes in its final pages instructions on modifying the Halfling class into a Gnome class, adding that as an option. The Creature Crucible series (Tall Tales of the Wee Folk, Top Ballista, The Sea People, Night Howlers) is about other racial classes, and Gazetteer series includes many optional classes for humans and non-humans, including the shaman (GAZ12) and shamani (GAZ14). Additional human and race classes are also presented in other supplements.

AD&D 2nd edition + Classes in 2nd edition Dungeons & DragonsGroupPlayer's HandbookSupplementsWarriorWizardPriestRogue――

The second edition of Advanced Dungeons & Dragons attempted to streamline what had become a hodgepodge of rules that only applied in specific cases in 1st edition. As such, it sought to simplify the rules and straighten out contradictions. Character classes are divided into four groups or "metaclasses": Warrior, Wizard, Priest, and Rogue. Each of these groups has a "base" class which only requires at least a 9 in the "prime requisite" ability in Fighter, Mage, Cleric, and Thief; these were intended to be playable in any setting. The Player's Handbook goes on to say that "all of the other classes are optional". Each group of classes has the same hit dice (determining hit point growth), THAC0 progression, and saving throw table. Second edition maintains minimums in certain statistics to qualify for some classes, but removes many of the other restrictions such as one extremely low ability forcing a character into a specific class.

The bard class was changed to be a normal class that can be chosen at character creation. The assassin and monk classes were removed from the second edition Player's Handbook. The Dungeon Master's Guide clarifies the rationale behind the decision in a section on creating new character classes: