Hit dice

Hit dice (singular hit die), abbreviated HD, are a rule in Dungeons & Dragons originally referring to the number of dice rolled to calculate how many hit points a character or monster begins play with. This determines how difficult they are to kill.

Throughout various rules editions of Dungeons & Dragons, hit dice also interact with other gameplay mechanics, including character level, experience, the strength of monster attacks, and recovering hit points at rest.

Mechanics

Hit points

In the original 1974 Dungeons & Dragons, a player character's hit dice are equal to their character level. A newly-created 1st level character rolls one die to determine their hit point total. A minotaur, which has six hit dice, rolls six dice to determine its hit point total.

While characters originally used six-sided dice to calculate hit points, an early innovation presented in Supplement I: Greyhawk (1975) gave classes different hit dice, giving fighters more hit points and magic-users fewer. This feature would be carried through to later editions of D&D.

A player character's Constitution score can increase or decrease their hit point total.

In some editions of D&D, a player character standardly gains the maximum possible roll at first level. This helps improve the survivability of characters at first level and avoids the situation where an unlucky player character can start with only a single hit point.

A rule, optional in some editions, allows players to take the average value instead of rolling the hit die. This also helps to avoid an unlucky player having a low number of hit points.

Spending hit dice

In D&D 5th edition specifically, a character can "spend" hit dice to heal out of combat. This essentially gives player characters reserve of hit points to recover outside of combat.

Other rules interactions

Hit dice are often synonymous with character level, and is often used in place of "level" when referring to monsters. As a result, many rules regarding monsters in particular are affected by hit dice.

In D&D 3rd edition in particular, several of a monster's statistics are calculated based on their hit dice, in the same way that some of a player character's stats are based on character level. These include base attack bonus, base saving throw bonus, number of feats, and the difficulty class of some supernatural attacks.

Some spells affect targets differently based on their hit dice. For example, color spray in D&D 3.5 is more effective against creatures with fewer hit dice.

Hit dice inflation

An observed phenomenon is that the type of die available to character classes tends to increase between editions of D&D. Fighters, originally using a d8, increased to d10, while wizards increased from d4 to d6. Rogues (originally called "thieves") began with d4 hit dice, but by D&D 5th edition had risen to d8.

Every character class appearing in OD&D has eventually had its hit dice increased in a later edition of the rules. The last to change was the assassin, who after 39 years increased from d6 do d8 by virtue of becoming a rogue subclass.

Publication history

Original D&D

In the original 1974 Dungeons & Dragons, "hit dice" was first used as an abbreviation for "Dice for Accumulative Hits". All hit dice, both for player characters and monsters, are rolled using six-sided dice. A player character's hit dice might not be equal to their level; a 9th level fighting-man has 9d6+3 hit points (nine hit dice with a 3 HP bonus), while a 9th level magic-user has 6d6+1.

Supplement I: Greyhawk (1975) introduces variable hit dice by class, with the express purpose of strengthening fighters and weakening magic-users. TSR editor Tim Kask would later attribute this to author Gary Gygax's idiosyncratic preference for Conan-esque fighters over wizards. High-level characters also now reached a cap on the total number of hit dice, perhaps to prevent characters becoming almost unkillable, a rule which would persist until its removal in D&D 3rd edition.

Including the OD&D supplements, character classes had the following hit dice in this edition of the game rules:

Hit Die	Classes in OD&D
d4	Magic-user, monk, thief
d6	Assassin, cleric, most monsters
d8	Fighter
d10	Powerful monsters only (Type IV demon, type VI demon, Demogorgon)
d12, d20	Powerful demons (defined in rules, but none of this power were listed)

Basic D&D

In all versions the Dungeons & Dragons product line which ran parallel to Advanced Dungeons & Dragons, races were considered classes. The following hit dice values were used by all of those editions:

Hit Die	Classes in Holmes Basic
d4	Thief, magic-user
d6	Cleric, elf, halfling, mystic
d8	Dwarf, fighter

Moldvay Basic (1981) allows a player to optionally reroll a 1 or 2 on their first hit die. The mystic appeared in the Rules Cyclopedia (1991), but not other editions. Some other classes appeared as a subclass, such as the avenger and paladin as subclasses of fighter, and druid as as subclass of neutral cleric, and base their hit dice.

Like OD&D and AD&D, characters of the Basic D&D eventually hit a hit dice cap at certain levels, and gain only fixed numbers of hit points thereafter.

AD&D 1st edition

Player characters now simply gain one hit die per level until they hit the maximum number of hit dice for their class. An unusual exception in AD&D 1e is that the ranger and monk gain two hit dice at level one.

Classes have the following hit dice:

Hit Die	Classes in AD&D 1e
d4	Illusionist, magic-user, monk
d6	Assassin, bard, thief, thief-acrobat
d8	Ranger (2d8 at 1st lvl), Cleric, druid, most monsters
d10	Cavalier, fighter, paladin
d12	Barbarian

Notably, the thief, cleric, druid and fighter increase one die type in this edition of the rules. Monsters also increase from d6 to d8. This has the overall effect of weakening magic-users further.

AD&D 2nd edition

The Player's Handbook (2e) (1989) makes no changes to AD&D's hit dice, but formally arranges the classes into archetypes which have the same hit die:

Hit Die	Classes in AD&D 2e
d4	Wizards (mage, illusionist, specialist wizards)
d6	Rogues (bard, thief)
d8	Priests (cleric, druid)
d10	Warriors (fighter, paladin, ranger)

AD&D 2e would be the last edition of the game to feature a hit dice cap below the character's total level. For example, a fighter above 9th level gains only a fixed 3 hit points per level and does not gain bonus hit points for high Constitution.

D&D 3rd edition

From D&D third edition onward, all player characters gain one hit die per character level, and add their Constitution modifier to hit points at all levels. This change made high-level characters and monsters exceptionally tough, except against effects like instant death and ability score drain.

Hit Die	Classes in D&D 3e	Monster types
d4	Wizard (including specialist wizards), sorcerer	—
d6	Bard, rogue	Fey
d8	Cleric, druid, monk, ranger (D&D 3.5)	Aberration, animal, elemental, giant, humanoid, monstrous humanoid, outsider, plant, shapechanger (D&D 3.0), vermin
d10	Fighter, paladin, ranger (D&D 3.0)	Beast (D&D 3.0), construct, magical beast, ooze
d12	Barbarian	Dragon, undead

This hit dice configuration borrows significantly from AD&D 2nd edition. The monk, which had not appeared in the AD&D 2e Player's Handbook, increased two die types from d4 to d8, while the barbarian returned as the only d12 class.

Third edition's prestige classes, too many to list here, used various hit dice from d4 to d12 and usually followed the typical base class to take that class; notably, the rogue-oriented assassin prestige class uses a d6 hit die; making it the only 3e class other than the wizard/magic-user to have retained its original hit die from OD&D.

In the D&D 3.5 revision (2003), the ranger was nerfed from d10, where it had been in earlier editions as a fighter or warrior subclass, to d8. A possible reason for this is a historical tendency to over-estimate the ranger's strength due to its potency in AD&D.

Monster hit dice are based on type, with most types using d8 hit dice, the most notable differences being Undead (who gain no Constitution bonus to hit points and need d12 hit dice), and Dragon (a menacing d12). Powerful demons, the sole owners of the highest hit die in original D&D, are now merely part of the Outsider type group with only d8 hit dice.

D&D 4th edition

D&D 4th edition abandoned the term "hit dice" in favor of "level", as player characters and monsters no longer roll randomly for hit dice, but gain a fixed number of hit points at each level. Constitution modifier is no longer added per level. However, characters gain a massive bonus to their hit points at first level, in addition to adding their entire Constitution score (not just modifier).

Examples of character classes appearing in Player's Handbook (4e) (2008), Player's Handbook 2 (4e) (2009) and Player's Handbook 3 (2010) include:

HP at first level	HP per level gained	Class
10	4	Invoker, wizard
12	4	Psion
12	5	Ardent, bard, cleric, druid, monk, ranger, rogue, runepriest, seeker, shaman, sorcerer, warlock, warlord
14	6	Avenger
15	6	Barbarian, battlemind, fighter, paladin
17	7	Warden

The starting hit point boost is the largest in D&D history, and is designed to allow players to skip the gritty, more fragile adventuring experience which had been represented by D&D 3rd edition's lowest character levels. D&D 4e intentionally took a perceived "sweet spot" in D&D 3e between level 5-15, and used this experience as the basis of D&D 4e's level 1-30.

Assuming that the hit points gained represent the average of each hit die rounded up, several classes gain a hit point boost from their D&D 3.5 versions: wizard, psion, bard, rogue, sorcerer, and warlock. The barbarian is demoted to the same hit point value as the fighter.

Monster "level", as well as monster role, is used to determine their hit points and other key statistics.. Level also determines the amount of XP gained for defeating a monster, replacing D&D 3e's more subjective challenge rating mechanic.

D&D 5th edition

In D&D 5th edition, "hit dice" is defined as an abbreviation for "hit point dice". The term represents both the dice rolled to determine a character or creature's hit points, and a new short-rest hit point recovery mechanic.

Hit Die	Classes in D&D 5e	Monster size
d4	—	Tiny
d6	Sorcerer, wizard	Small
d8	Artificer, bard, cleric, druid, monk, rogue, warlock	Medium
d10	Fighter, paladin, ranger	Large
d12	Barbarian	Huge
d20	—	Gargantuan

In comparison to D&D 3.5, the wizard and sorcerer have gone from d4 to d6; the bard, rogue and warlock have gone from d6 to d8; and the ranger has been restored to its AD&D-era d10 hit die. Compared to D&D 4e, the bard, rogue, warlock and wizard have retained their hit point improvements, the sorcerer has been reduced to meet the wizard, while the ranger and barbarian have been promoted one die type to meet their status previous editions.

Monster hit dice are now based on size rather than type.

Player characters can now "spend" hit dice to recover hit points during a short rest. For example, a level 5 barbarian with d12 hit dice and a Constitution modifier of +3 can roll to recover 1d12+3 hit points, and can do this a number of times equal to their barbarian level.