In the Dungeons & Dragons role-playing game, game mechanics and dice rolls determine much of what happens. These mechanics include:
Ability scores, the most basic statistics of a character, which influence all other statistics Armor class, how well-protected a character is against physical attack Hit points, how much punishment a character can take before falling unconscious or dying Saving throws, a character's defenses against nonphysical or area attacks (like poisons, fireballs, and enchantments) Attack rolls and damage rolls, how effectively a character can score hits against, and inflict damage on, another character Skills, how competent a character is in various areas of expertise Feats, what special advantages a character has through natural aptitude or training
Ability scores
All player characters have six basic statistics: Strength (STR): Strength is a measure of muscle, endurance and stamina combined; a high strength score indicates superiority in all these attributes. Strength affects the ability of characters to lift and carry weights, melee attack rolls, damage rolls (for both melee and ranged weapons), certain physical skills, several combat actions, and general checks involving moving or breaking objects. Dexterity (DEX): Dexterity encompasses a number of physical attributes including hand-eye coordination, agility, reflexes, fine motor skills, balance and speed of movement; a high dexterity score indicates superiority in all these attributes. Dexterity affects characters with regard to initiative in combat, ranged attack rolls, armor class, saving throws, and other physical skills. Dexterity is the ability most influenced by outside influences (such as armor). Constitution (CON): Constitution is a term which encompasses the character's physique, toughness, health and resistance to disease and poison; a high constitution score indicates superiority in all these attributes. The higher a character's constitution, the more hit points that character will have. Constitution also is important for saving throws, and fatigue-based general checks. Unlike the other ability scores, which render the character unconscious or immobile when they hit 0, having 0 Constitution is fatal. Intelligence (INT): Intelligence is similar to IQ, but also includes mnemonic ability, reasoning and learning ability outside those measured by the written word; a high intelligence score indicates superiority in all these attributes. Intelligence dictates the number of languages a character can learn, and it influences the number of spells a preparation-based arcane spell-caster (like a Wizard) may cast per day, and the effectiveness of said spells. It also affects certain mental skills. Wisdom (WIS): Wisdom is a composite term for the character's enlightenment, judgment, wile, willpower and intuitiveness; a high wisdom score indicates superiority in all these attributes. Wisdom influences the number of spells a divine spell-caster (such as clerics, druids, paladins, and rangers) can cast per day, and the effectiveness of said spells. It also affects saving throws and linked skills. Charisma (CHA): Charisma is the measure of the character's combined physical attractiveness, persuasiveness, and personal magnetism; a high charisma score indicates superiority in all these attributes. A generally non-beautiful character can have a very high charisma due to strong measures of the other two aspects of charisma. Charisma influences how many spells spontaneous arcane spell-casters (such as sorcerers and bards) can cast per day, and the effectiveness of said spells.
An ability score is a natural number, with a value of 10 or 11 representing average ability. "These ability scores help determine whether [a] character succeeds or fails at something they try" when a player rolls a d20. For example, "a Dwarf with 15 strength can probably lift up a huge rock quite easily. A wizard with 6 wisdom probably won't realize when they're getting conned. A bookish monk with 20 intelligence but just 4 constitution [...], would intuitively know the perfect regimen for training for a marathon, but couldn't even come close [to] completing one".
Ability modifiers Beginning with the 3rd Edition, each score has a corresponding ability modifier, where Modifier = , rounded down. It acts as a bonus or penalty depending on a character's ability scores. This modifier is added to the appropriate dice rolls. For example, the strength modifier would be added to the damage dealt by a sword, the dexterity modifier to Armor Class (see below) as the character's ability to dodge attacks, and the charisma modifier to an attempt to smooth-talk a merchant.
Determining ability scores
In AD&D, ability scores were "determined by rolling three 6-sided dice and adding up their values". This had a significant impact on character creations as "certain classes could only be taken up by characters with the right combination of statistics. As a result, players often" re-rolled characters until they ended up with the combination of ability scores they desired. The point buy system was originally added as an optional ruleset in the second edition supplement Player's Option: Skills & Powers (1995) and while it is "largely incompatible with most of the other books released for AD&D second edition" it still "proved very popular among fans". "A point system to ensure total player control over the character's attributes while at the same time limiting just how powerful the character could become [...] [was] formalized in the third edition".
There are now several methods of determining a character's initial ability scores during character creation:
Rolling dice (3d6): This is the standard method for older editions. For each ability score, the player rolls 3d6, and adds the values, resulting in scores ranging from three to eighteen, averaging 10.5. Rolling dice (4d6, keep 3): This is the standard method since 3rd edition.Dungeon Master's Guide 3rd Edition, p. 169. For each ability score, the player rolls 4d6, and adds the three highest values, resulting in scores ranging from three to eighteen, skewed towards higher numbers, averaging 12.24, though the most probable result is 13. Predetermined array of scores: Each player uses the same set of numbers, choosing which ability score to apply them to. Point buy: In the point buy system, a player has a certain number of points to spend on ability scores, and each score has a certain point cost affixed to it, where higher scores cost more points than lower ones.
Optional ability scores Comeliness (COM): In the first edition of AD&D, comeliness was introduced as a seventh ability score in the supplemental rulebook Unearthed Arcana and Oriental Adventures to differentiate between physical attractiveness and charisma. Comeliness has not appeared as an officially supported ability score since, although the second edition supplement Player's Option: Skills & Powers (1995) included optional rules for splitting each ability score into two sub-scores with "appearance" as a "subability" score of Charisma. Sanity (SAN): This ability score was introduced by the Call of Cthulhu role-playing game in 1981, but it was not officially introduced into the core D&D rules until the 5th Edition Dungeon Master's Guide (DMG, 2014) as an optional score for campaigns shaped by the constant risk of insanity. It is checked for actions "around entities of an utterly alien and unspeakable nature" and used with the Madness ruleset. The 5th Edition campaign guide Van Richten's Guide to Ravenloft (2021) added new "Fear and Stress" rules as a replacement for the "Madness and Sanity" rules suggested in the DMG. Christian Hoffer, for ComicBook.com, called the previous Madness ruleset "dated" and highlighted that "the 'Stress' mechanic is a more straightforward alternative to the 'Madness" mechanic' [...] With this new ruleset, each player has a Stress Score that increases in trying situations and decreases when players take steps to mentally fortify themselves with care or support. [...] When a player has a Stress Score, they subtract that score whenever they make an attack roll, ability check, or saving throw". Honor (HON): An optional score included in sourcebooks such as the first edition Oriental Adventures and the 5th Edition DMG. Honor determines how well the character adheres to the respective society's code, how well they understands its tenets, and it may also reflect others' perception of the character's honorability. Mechanically, it is used in social interaction in situations in which it may be more relevant than a person's charisma or in a saving throw. Unlike the regular six ability scores, Honor cannot be raised by the player after character creation. Instead, the dungeon master can increase or decrease its value at the end of an adventure according to the player character's actions throughout it. The 5th Edition DMG suggests using honor in campaigns with "cultures where a rigid code of honor is part of daily life"; the DMG also suggests using this score in settings "inspired by Asian cultures, such as Kara-Tur". Aaron Trammell, in the academic journal Analog Game Studies, wrote that "unlike honor for a paladin in a traditional Dungeons & Dragons campaign, Honor in this context has been detached from the ethical matrix of alignment. Honorable characters in Oriental Adventures can be evil, and dishonorable characters in Oriental Adventures can be good. [...] Honor is a paradigm case of Orientalism in Dungeons & Dragons, as it explicitly compares an imagined Oriental ethic and the West".
Combat
Armor class
Armor class (AC) is a rating used to determine how difficult it is to damage a creature/character. It is based on several factors such as a creature's natural aversion to physical injury, magical enhancements, and any protective garments worn. The dexterity ability score grants bonuses to AC. In the original game, armor class ranged from 9 to 0, because armor and dexterity modifiers were applied to hit rolls instead. Negative values first appeared in the Greyhawk supplement, because it first applied them directly to the Armor Class. In editions prior to 3rd, armor class ranges from -10 to 10. Having an AC of 10 was the weakest, and a -10 being the strongest possible written AC.Livingstone (1982:77). In subsequent editions, armor class instead starts at 10 and increases. Extremely non-dexterous or non-moving creatures may suffer penalties that lower their armor class below 10.
Defenses In 4th edition, there are three defenses that function similarly to armor class. Fortitude is based on strength or constitution; it represents a character's endurance to pain. Reflex is based on dexterity or intelligence and can be modified by a shield; it represents a character's ability to dodge. Will is based on wisdom or charisma; it represents a character's strength of mind and resistance to mental attack. These defenses are typically lower than AC, so an attack against fortitude is usually better than an attack against AC.
Hit points Hit points (HP) are a measure of a character's vitality or health; they are determined by the character's class or race, and Constitution score. Hit points are reduced whenever a character takes damage.
In the original D&D game a character died when his/her hit point total reached 0. First edition AD&D introduced an optional rule in which a character died when his/her hit points reached -10, with beings falling unconscious at 0 HP, and creatures reduced to negative HPs continue to lose HPs due to bleeding, etc. unless they are stabilized by aid or healing (natural or magical). In third edition, this rule became part of the core rules.