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The Dungeon Master, usually abbreviated to DM, is the player in a Dungeons & Dragons game with the responsibility to adjudicate the rules, control all monsters and describe the game environment.

The term Game Master (abbreviated GM) is also used, particularly in roleplaying games other than Dungeons & Dragons, where the trademark registered by Wizards of the Coast was not licensed for use. In early editions of D&D, the term referee was also used.


In a typical game of Dungeons & Dragons, most players control a fictional character, termed a player character. One player, the Dungeon Master, does not control a player character of their own, but instead assumes numerous responsibilities.

In a general sense, the Dungeon Master assumes the role of the computer in a video game RPG, responding to the players' actions with a combination of game rules and human creativity in order to create the sense of a believable and consistent game world.

Rules referee

The Dungeon Master is expected to be familiar with the game rules, and to interpret and adjudicate those rules fairly in the manner of a judge. They also have the authority to invent a reasonable answer to a rules question which is not necessarily supported by the rulebooks, known as making a ruling.

For example, the Dungeon Master's Guide (3.5) (2003), p.6, Adjudicating, describes this duty as follows:

...you're the final arbiter of rules within the game. Good players will always recognize that you have ultimate authority over the game mechanics, even superseding something in a rulebook. Good DMs know not to change or overturn a published rule without a good, logical justification so that the players don't rebel (more on that later).
To carry out this responsibility, you need to know the rules. You're not required to memorize the rulebooks, but you should have a clear idea of what's in them, so that when a situation comes up that requires a ruling, you know where to reference the proper rule in the book.

The DM is also expected to help the players learn the game rules.[1] In many groups, the DM will be an experienced D&D player.


The DM determines and describes what the player characters see and hear, including their surroundings, their opponents, and the results of their actions.

While each player freely controls their own indvidual character, the DM holds the responsibility for determining and describing the actions of other people in the game world. Characters controlled by the DM are known as non-player characters, and may include villains, allies, and neutral bystanders.

The DM also controls creatures in the world, such as the monsters who appear in dungeons. They roll dice, manage statistics and make decisions for all enemies in combat.

The DM's narration can set the tone of the game. Many DMs enjoy acting in-character as the various NPCs of their world, while some prefer detailed descriptions of ancient dungeon terrain.


The DM is responsible for creating many elements of the world, including its dungeons, monsters, non-player characters, campaign setting and key story elements.

Elements of the game world can be both prepared in advance and created or adapted on-the-fly. They may be fully original, or based on an existing Dungeons & Dragons sourcebook.

Creating the world is a careful balancing act. DMs need to be sufficiently prepared to ensure that their players have a satisfactory experience, but not over-prepared, since the freedom of player choice in D&D makes if possible that much of a DM's hard work may be wasted. Much of a D&D campaign is therefore ad-libbed and invented on the fly, a core skill for any Dungeon Master.

Historically, all Dungeon Masters were expected to create their own original dungeons from scratch in advance. The original Dungeons & Dragons stated:[2]

"First, the referee must draw out a minimum of half a dozen maps of the levels of his "underworld", people them with monsters of various horrid aspect, distribute treasures accordingly, and note the location of the later two on keys, each corresponding to the appropriate level."

However, a Dungeon Master need not create all of his material from scratch. DMs commonly make use of D&D sourcebooks, such as published campaign settings and adventure modules. Even so, it is within the DM's ability to modify official material to suit their game, as they see fit. The D&D 5th edition Dungeon Master's Guide states:[3]

"Every DM is the creator of his or her own campaign world. Whether you invent a world, adapt a world from a favorite movie or novel, or use a published setting for the D&D game, you make that world your own over the course of a campaign."

Other responsibilities

Unofficially, the DM may also take on other tasks. These include recruiting new players, organizing play time, purchasing miniatures and other materials, enforcing table etiquette, providing a location for the game to take place, and assisting new players in character creation.


The role of Dungeon Master arose from that of a referee in tabletop miniature wargaming, a rule expert who served as a neutral arbiter between players. The original Dungeons & Dragons (1974) used the term "referee" to refer to the DM, as the term Dungeon Master was not invented until later.

Etymology and usage

According to Playing at the World, the term Dungeon Master is thought to derive from "gamesmaster", a term used to describe the referee of play-by-mail games of Diplomacy, and used in the contexts of Dungeons & Dragons in fanzines published in 1974. "Gamemaster" appeared as early as Dragon #2 (Aug 1976), p.4, in the article Monkish Combat in the Arena of Promotion.

The term "Dungeon Master" is believed to have originated in the early D&D fan community. The earliest known use of the term appears in the game fanzine APA-L #510, dated Feb 20, 1975:

If you picked up a stranger in the Dungeon and let him join your party, does the Dungeonmaster handle it? I have hundreds of questions, most of which I expect the rulebooks to answer.

"Dungeon Master" did not appear in a Dungeons & Dragons book until Eldritch Wizardry (1976), and began appearing in Dragon Magazine with a reader's letter in Dragon #5 (Mar 1977), although although the older term "gamemaster" continued to see some use. Playing at the World estimates that gaming fanzines initially helped to popularize "Dungeon Master" among the D&D community.

The official status of the term "Dungeon Master" to refer to the game referee was solidified by AD&D 1st edition, which named one of its core rulebooks the Dungeon Masters Guide (1e) (1979).

From 1989 onward, TSR (and later Wizards of the Coast) asserted a trademark on the terms "Dungeon Master" and "DM". The Dungeon Master Guide (2e) (1989) styled itself "The DUNGEON MASTER™ Guide", perhaps to avoid the awkwardness of ending a word in the letter "S" after a trademark symbol; i.e. DUNGEON MASTER™S Guide or Dungeon Master™'s Guide.

To avoid trademark disputes and distinguish themselves from Dungeons & Dragons, many roleplaying games use alternative terms in place of "Dungeon Master". A popular term is "Game Master" (abbreviated GM), used by RPGs including Pathfinder and Dungeon World. Some use iconic identifiers such as D&D retro-clone Labyrinth Lord, whose game master is called the "Labyrinth Lord", and Castles & Crusades, who uses "Castle Keeper".

Reception and influence

In a 2020 YouTube video, former TSR employee Tim Kask gave his opinion that the DM is the ultimate authority in his game:[4]

"DMs, no-one has the right—no-one has the privilege of telling you how ought to do something."

Further reading

The primary guidebook for Dungeon Masters is the Dungeon Master's Guide, one of three core rulebooks included in the most prominent editions of Dungeons & Dragons. For example, a DM of Dungeons & Dragons 5th edition is highly encouraged to read the Dungeon Master's Guide (5e) (2014).

Dungeon Master's Guides from earlier editions of D&D are also valuable. While the rules for older editions no longer apply, each Dungeon Master's Guide provides valuable advice and insight into the art of being a Dungeon Master.

D&D 5th edition includes Appendix D, a recommended reading list specifically for Dungeon Masters.