D&D has its own vocabulary, and most of it is short for something simple. A Game Master (GM, or DM in D&D) runs the world; players run player characters (PCs); everyone else is a non-player character (NPC). When an action could fail, you roll a twenty-sided die (d20), add a modifier and try to reach a Difficulty Class (DC). Attacks aim at Armor Class (AC), damage comes off hit points (HP), and a saving throw is a roll to resist something. This glossary explains about 80 terms in plain words, grouped the way a new player meets them: the table, dice, combat, magic, the character, the world and the slang.
The ten terms you need first
- Game Master (GM / DM): the person who describes the world, plays every other character and calls for rolls.
- Player character (PC): the hero you play. Non-player character (NPC): everyone else in the world.
- d20: the twenty-sided die that decides success or failure.
- Modifier: the number you add to the die, based on how good your character is at the task.
- Difficulty Class (DC): the number your total has to reach. Equal counts as success.
- Armor Class (AC): how hard a creature is to hit. Attacks roll against it.
- Hit points (HP): how much harm a character can take before falling.
- Saving throw: a roll to resist something happening to you, like poison or a fireball.
- Advantage / disadvantage: roll two d20s and keep the higher, or the lower.
- Natural 20 / natural 1: the die itself shows 20 or 1, before modifiers. The best and worst possible roll.
How to use this glossary
The terms are grouped by where you meet them, not alphabetically, so you can read one section before a session and skip the rest. Definitions follow the 5e-style rules most tables play; where the 2014 rules and the 2024 revision use different words (race and species, for example), both are given. Abbreviations are in brackets. The rules themselves are explained in more depth in the dice and checks guide and the character creation guide.
The table and the people
| Term | What it means |
|---|---|
| Game Master (GM), Dungeon Master (DM) | The person who runs the game: describes scenes, plays every non-player character, sets difficulties and keeps the rules moving. DM is the traditional D&D name; GM is the general one. |
| Player character (PC) | A character controlled by a player. Each player usually has one. |
| Non-player character (NPC) | Any character the Game Master plays: the innkeeper, the villain, the talking cat. |
| Party | The group of player characters adventuring together. |
| Session | One sitting of play, usually three to four hours. |
| Campaign | A long story played over many sessions with the same characters. |
| One-shot | A complete adventure that starts and ends in a single session. Ideas are in the one-shot guide. |
| Adventure, module | A prepared scenario with places, characters and a plot. A campaign is often a chain of adventures. |
| Session zero | A planning meeting before the campaign: tone, themes, limits, house rules, schedule and how the characters are connected. |
| Lines and veils | A safety tool. A line is content that never appears in the game; a veil is content that can happen but off screen. |
| House rule | A rule a particular table changes or adds. Very common and perfectly normal. |
| Rules as written (RAW), rules as intended (RAI) | RAW is what the rule text literally says; RAI is what it was probably meant to do. Used when a rule is unclear. |
| Table talk | Players talking to each other as players, not in character. Some tables limit it during tense scenes. |
| In character (IC), out of character (OOC) | Speaking as your character, or as yourself. |
Dice and checks
| Term | What it means |
|---|---|
| Polyhedral dice (d4, d6, d8, d10, d12, d20, d100) | The standard set of seven dice. The number after the d is how many sides it has. A d100 is usually two d10s, one for tens and one for ones. |
| d20 | The twenty-sided die. Every check, saving throw and attack roll uses it. |
| Dice notation (2d6+3) | Roll two six-sided dice, add them, add 3. The first number is how many dice, the second is how many sides. |
| Modifier (mod) | The number added to or subtracted from a roll. Usually your ability modifier, sometimes plus a bonus. |
| Ability modifier | Derived from an ability score: subtract 10, divide by 2, round down. A score of 16 gives +3. |
| Proficiency bonus | An extra bonus for things your character is trained in. It starts at +2 and grows with level. |
| Difficulty Class (DC) | The target number for a check or save. Roughly 10 is easy, 15 medium, 20 hard. |
| Ability check | A d20 roll to try something uncertain: climb, sneak, persuade, remember. |
| Skill | A trained area within an ability, such as Stealth (Dexterity) or Persuasion (Charisma). "Make a Perception check" means a Wisdom check using the Perception skill. |
| Saving throw (save) | A d20 roll to resist something done to you: a trap, a poison, a spell. Each ability has its own save. |
| Advantage, disadvantage | Roll two d20s and keep the higher (advantage) or the lower (disadvantage). They do not stack, and one of each cancels out. |
| Natural 20 (nat 20), natural 1 (nat 1) | The die itself shows 20 or 1, before modifiers. A nat 20 on an attack always hits and is a critical; a nat 1 always misses. |
| Critical hit (crit) | A natural 20 on an attack. The damage dice are rolled twice, the modifier is not doubled. |
| Passive score (passive Perception) | A fixed number, 10 plus your modifier, used when the GM checks something without asking you to roll, such as noticing a hidden guard. |
| Contested check | Two characters roll against each other, for example grappling or sneaking past a watchful guard. Higher total wins. |
| Inspiration | A reward the GM gives for good roleplay. You can spend it later for advantage on a roll. |
| Help (the Help action) | One character assists another, giving advantage on their next roll at that task. |
Combat
| Term | What it means |
|---|---|
| Initiative | A Dexterity roll at the start of a fight that sets the order in which everyone acts. |
| Round | One full cycle in which every creature in the fight takes a turn. About six seconds of game time. |
| Turn | Your part of the round: you can move and take an action, and sometimes a bonus action. |
| Action | The main thing you do on your turn: attack, cast a spell, dash, dodge, help, hide. |
| Bonus action | A quick extra action that only certain abilities and spells allow. You get at most one per turn. |
| Reaction | Something you can do outside your turn in response to a trigger, once per round. The opportunity attack is the most common. |
| Opportunity attack | A free attack against an enemy who moves out of your reach without being careful. |
| Speed, movement | How far you can move on your turn, usually 30 feet (six squares on a grid). |
| Attack roll | A d20 plus your attack bonus, against the target's Armor Class. |
| Armor Class (AC) | How hard a creature is to hit. 10 plus Dexterity without armour; heavier armour and shields raise it. |
| Hit points (HP) | How much damage a character can take. At 0 a player character falls unconscious. |
| Temporary hit points (temp HP) | A buffer that absorbs damage first and is not restored by healing. |
| Damage, damage type | What comes off hit points after a hit. Types include slashing, fire, poison and others. |
| Resistance, vulnerability, immunity | Taking half, double or no damage from a damage type. |
| Conditions | Lasting states with set effects: poisoned, frightened, prone, stunned, blinded, grappled and so on. |
| Death saving throws (death saves) | At 0 HP you roll a d20 each turn: three successes and you stabilise, three failures and the character dies. |
| Cover | An obstacle between you and an attacker that raises your AC or blocks the attack. |
| Grid, theatre of the mind | Fighting on a squared map with tokens, or purely in description. Compared in the grid vs theatre of the mind guide. |
Magic
| Term | What it means |
|---|---|
| Spell slot | A unit of magical energy that a spell uses up. Higher-level spells need higher-level slots. Slots come back after a long rest (some classes after a short one). |
| Cantrip | A minor spell you can cast as often as you like, with no slot. |
| Spell level | How powerful a spell is, from 1 to 9. Not the same as character level. |
| Concentration | Some spells last only while you keep concentrating. Taking damage forces a save to keep it, and you can concentrate on one spell at a time. |
| Spellcasting ability | The ability that powers your magic: Intelligence, Wisdom or Charisma depending on the class. |
| Spell save DC | The DC an enemy must beat to resist your spell: 8 + proficiency bonus + spellcasting modifier. |
| Spell attack | A d20 roll to hit a target with a spell, against its AC. |
| Components (V, S, M) | What casting needs: Verbal (words), Somatic (gestures), Material (an object or focus). |
| Ritual | A spell that can be cast slowly, over ten extra minutes, without using a slot. |
| Area of effect (AoE) | A spell that hits everything in a shape: a sphere, a cone, a line. |
| Prepared spells, known spells | Some casters choose each day from a list (prepared); others have a fixed set they always know (known). |
Your character
| Term | What it means |
|---|---|
| Character sheet | The page that holds all of your character's numbers, gear and notes. |
| Ability scores (STR, DEX, CON, INT, WIS, CHA) | Six numbers: Strength, Dexterity, Constitution, Intelligence, Wisdom, Charisma. Usually between 8 and 20. |
| Class | Your character's role and toolbox: Fighter, Rogue, Wizard, Cleric and so on. |
| Subclass | A specialisation within a class, usually chosen at level 3. |
| Race, species, origin | What your character is: human, elf, dwarf and others. Older rules say race, the 2024 revision says species. |
| Background | What your character did before adventuring: soldier, scholar, criminal. Gives skills and story hooks. |
| Level | How experienced a character is, from 1 to 20. Each level brings new abilities and more hit points. |
| Experience points (XP) | Points earned by overcoming challenges. Enough XP means a new level. Some tables skip XP and level everyone up at milestones. |
| Milestone levelling | Levelling up when the story reaches a key point instead of counting XP. |
| Hit dice | A pool of dice tied to your class (d6 to d12) that sets your hit points and lets you heal during a short rest. |
| Feat | A special talent that changes how your character works, such as being tougher or a better archer. |
| Ability Score Improvement (ASI) | At certain levels you raise ability scores (usually +2 in total) or take a feat instead. |
| Multiclassing | Taking levels in a second class. |
| Alignment | A two-word shorthand for a character's moral outlook, such as lawful good or chaotic neutral. |
| Backstory | Your character's history before the game. A few sentences with a goal and an open problem work better than pages. |
| Build | A planned combination of class, abilities and feats meant to work well together. |
Adventure and world
| Term | What it means |
|---|---|
| Setting | The world the game takes place in, with its places, history and rules of magic. |
| Dungeon | Any dangerous enclosed place to explore: a cave, a tomb, a ruined fortress. |
| Encounter | A scene with a challenge: a fight, a negotiation, a trap, a puzzle. |
| Random encounter | An encounter decided by a roll on a table rather than planned in advance. |
| Hook | The reason a story grabs the characters: a job offer, a missing friend, a strange map. |
| Quest | A task with a goal the party has taken on. |
| Loot, treasure | What the party finds or earns: coins, gear, magic items. |
| Magic item | An item with magical properties. Usually graded by rarity: common, uncommon, rare, very rare, legendary. |
| Attunement | A bond some magic items need before they work. A character can be attuned to only a few items at once. |
| Short rest, long rest | A pause of about an hour (short) or a night's sleep (long) that restores hit points and abilities. |
| Downtime | Time between adventures spent crafting, training, working or recovering. |
| Boss | The strongest enemy of an adventure, usually met at the end. |
Table slang
None of these are rule terms, and you will hear all of them. Several describe behaviour rather than mechanics; they are best used to talk about play styles, not to label a person.
| Term | What it means |
|---|---|
| TPK (total party kill) | Every character in the party dies or is defeated in the same encounter. |
| BBEG (big bad evil guy) | The main villain of a campaign. |
| Metagaming | Acting on knowledge your character does not have, such as a monster's stats read in a book. |
| Murderhobo | A rootless character who solves every problem by killing it, shopkeepers included. |
| Railroading | The GM forcing one planned path so player choices stop mattering. |
| Sandbox | An open campaign where the players choose where to go and what to pursue. |
| Homebrew | Content a table makes itself: monsters, classes, a whole world. |
| Min-maxing | Maximising strengths and dumping weaknesses to make a character as effective as possible. |
| Power gamer | A player mainly focused on making their character as strong as the rules allow. |
| Rules lawyer | A player who argues rules closely, sometimes at the cost of the game's pace. |
| Rule of cool | If something is awesome and fits the scene, let it work even if the rules are unclear. |
| Yes, and | An improv habit: accept what another player establishes and build on it. |
| Fudging | The GM secretly changing a roll result, usually to save a character or a scene. Tables disagree on it. |
| Don't split the party | Classic advice: a divided group is slower to play and easier to kill. |
| Dump stat | The ability you deliberately leave low, often Charisma or Strength. |
| Party face | The character who does most of the talking with NPCs, usually the one with the best Charisma. |
| Tank | A tough character who stands in front and draws enemy attacks. |
| Glass cannon | A character who deals heavy damage but goes down quickly. |
Abbreviations at a glance
| Abbreviation | Stands for |
|---|---|
| GM / DM | Game Master / Dungeon Master |
| PC / NPC | Player character / Non-player character |
| DC | Difficulty Class |
| AC | Armor Class |
| HP | Hit points |
| XP | Experience points |
| STR, DEX, CON, INT, WIS, CHA | The six abilities |
| ASI | Ability Score Improvement |
| AoE | Area of effect |
| IC / OOC | In character / Out of character |
| RAW / RAI | Rules as written / Rules as intended |
| TPK | Total party kill |
| BBEG | Big bad evil guy |
| PvP | Player versus player: characters fighting each other |
These terms in Thavernia
Thavernia is a tabletop RPG where the Game Master is an AI. Its rules are a simplified 5e style, so most of the vocabulary above applies directly, with a few deliberate changes. This is how the terms map onto the game as it works today:
| Term | In Thavernia |
|---|---|
| Game Master | An AI narrates, plays the NPCs and responds to what you write. It is instructed never to decide your character's actions for you. |
| Session zero | Creating a campaign covers it: you pick themes and a tone, write an adventure idea of up to 500 characters, choose the narration language, and choose a one-shot or a long campaign. |
| d20, DC, modifier | Two-phase dice: the server fixes each d20 when the check is set, you throw the 3D die on screen, and the narration is written after it lands. A badge shows the raw d20, your modifier, the total and the DC. |
| Natural 20 / natural 1 | Applies to every roll, not only attacks: a 20 succeeds and a 1 fails whatever the DC. |
| Advantage, Help | Advantage shows two dice on screen. In a group, the Lend a hand button turns a teammate's roll into an advantage roll, once per player per round of dice. |
| Armor Class | You usually roll to defend (dodge, block, brace) instead of the enemy rolling against a fixed AC. |
| Action, bonus action | On the tactical board, each class has an action kit and a budget of action points per round instead. |
| Conditions | Poisoned, Bleeding and Burning deal a little damage each round; Frightened gives disadvantage, Blessed gives advantage; heroes attack a prone foe with advantage. |
| Short rest, long rest | Make camp: outside combat, the party recovers half of the hit points it is missing, shakes off conditions and recharges each class's signature move. It can only be used again after several Game Master turns. |
| Grid, theatre of the mind | Both exist: a tactical board, or a narrative mode with no grid. |
| NPC | Every named NPC has a recorded attitude toward the party (friendly, neutral, hostile or unknown) and reacts in character to how you treat them. |
| Party, sidekick | Up to six seats per table, shared between friends and up to two AI companions with their own hit points and decisions. |
| XP, level, ASI | Experience comes only from what you do in the story. Every fourth level gives 2 ability points to spend. |
| Loot, magic item | Items are found in play. Only equipped gear counts, with a fixed bonus by rarity. |
| Downtime | Between adventures there is a town with a tavern job board and crafting workshops. |
| TPK, PvP | Characters can die, and friendly fire is real: a blow inside the party comes off your friend's hit points. |
What Thavernia does not have, said plainly: there are no spell slots to track, no feats or subclasses to pick at creation and no separate damage dice for kit actions. Why the dice cannot be bent by the AI is shown on the is the AI Game Master fair? page.
Try it yourself
Vocabulary sticks fastest at a table. The trial needs no account and no card and gives you three turns as a guest; a free account then gives you 20 turns. Try something risky and read the badge: the d20, the modifier and the DC are all there.
Frequently asked questions
What are the most important D&D terms for a beginner?
Ten cover almost everything in a first session: Game Master (GM or DM), player character (PC), non-player character (NPC), d20, modifier, Difficulty Class (DC), Armor Class (AC), hit points (HP), saving throw and advantage. If you know those, you can follow any table and pick the rest up as it comes.
What is the difference between a DM and a GM?
None in practice. Both mean the person who runs the game: describes the world, plays every non-player character and decides when a roll is needed. "Dungeon Master" is the name traditionally used in D&D; "Game Master" is the general term used across tabletop roleplaying games.
What does nat 20 mean?
A natural 20: the twenty-sided die itself shows 20, before any modifier is added. Under the standard rules a natural 20 on an attack always hits and is a critical hit. Many tables also treat it as an automatic success on any roll, as a house rule. A nat 1 is the opposite: the die shows 1.
What is a TPK?
A total party kill: every character in the group dies or is taken out in the same fight. It usually ends the campaign or forces a new start, which is why good Game Masters warn when a fight is far too strong and why retreating is always a valid option.
What is metagaming?
Using knowledge your character could not have. Reading a monster's weaknesses from a rulebook and acting on them, or reacting to a plan you heard as a player but your character never did, are the usual examples. Most tables ask players to keep player knowledge and character knowledge apart.
What does murderhobo mean?
A joking term for a character, or a whole party, that wanders without roots and solves every problem by killing it, including shopkeepers and quest givers. It is not a rule term; it describes a play style that usually spoils the story for the rest of the table.
What is railroading in D&D?
When the Game Master forces the story down one planned path no matter what the players choose, so their decisions stop mattering. Its opposite is a sandbox, an open world where the players pick the direction. Most tables sit in between.
What is session zero?
A meeting before the campaign starts, without dice, where the group agrees on tone, themes, content limits, house rules, how often it meets and how the characters know each other. It prevents most of the arguments that otherwise surface three sessions in.
Do I need to learn all these terms before my first game?
No. Learn the ten in the first section and ask about the rest when they come up. Every table explains its own words, and an AI Game Master like Thavernia's does the bookkeeping for you: you write what your character does, and the checks, DCs and hit points are handled by the game. The [trial](/trial) needs no account.