Update: The finished glossary is available here: RPG Glossary.

This is a first pass at a glossary of GMing terms. This glossary attempts to cover every gaming term that is both related to GMing and common to most RPGs.

A lot of these terms originated with D&D, but they’re so widely used they’ve have effectively become the default terms (even though many other RPGs call them different things).

Because I want this glossary to be useful to GMs of all skill levels, it includes some very basic terms. (Even veteran GMs might find some surprises here, though.)

I’m sure I’ve forgotten something, or bollixed up a definition (or several!), and I’d love your help improving this glossary. Once it’s been out there for a bit, I’ll probably make it a permanent TT page (linked in the sidebar).

I might also publish it in another form (like a PDF, or maybe even a book) sometime down the road, and I’d like to include your contributions in that publication.

For that reason, if you comment below, please be aware that I may use your comment in a published version of this glossary. By commenting on this post, you agree to let me do that.

Treasure Tables RPG Glossary

A series of linked encounters, often played out in one or two sessions, in which the PCs overcome a variety of obstacles. Adventures can be linked together to form a campaign. (Synonymous with scenario.)

Also called game balance, the idea that all PCs should start the game at the same power level and that enemies and challenges should be appropriate to that power level. Can also apply to other game elements, such as monsters and items. Elements that are not balanced are often referred to as being broken; nerfing broken elements is a way to make them balanced again.

A map on which encounters are played out with counters or miniatures, often eraseable.

Big Bad Evil Guy, slang for the central villain in an adventure or campaign.

Originally a video game term, bosses are powerful foes who require significant resources to defeat. In a given area, there is usually only one boss (though a boss will sometimes have sub-bosses).

A broken rules element is flawed in some way, most often by being too powerful or not powerful enough.

When you need to take an extended break from GMing, you’re suffering from burnout. Burnout is most often caused by GMing too often or under frustrating circumstances.

A linked series of adventures, usually with a central theme or storyline that ties them together.

Campaign Journal
A record of what happens during your gaming sessions. Campaign journals can range from a simple list of events to prose-style accounts, generally used to keep track of what happens during your campaign.

Established elements of a published setting. Published supplements generally support the canon. Some gamers are quite passionate about sticking to canon, and prefer not to diverge from it.

Everyone in the game world is a character. This term applies to both PCs and NPCs.

A battle, generally between PCs and NPCs or PCs and monsters.

Short for convention, a con is a gathering where gamers get together to play RPGs and buy gaming stuff.

Any small, flat item that represents a character or monster, generally used in conjunction with a battlemat. Counters are an alternative to miniatures.

Slang for the mechanical elements of any RPG.

Deus ex Machina
Latin for “God from the machine,” a deus ex machina is a plot device that dramatically alters the outcome of a situation without regard to suspension of disbelief or the actions of the PCs. Closely related to GM fiat, and generally frowned upon.

The time between adventures, when the PCs get a chance to rest, heal, train and resupply.

Taking an idea or rules element from one RPG and incorporating it into a different RPG. For example, importing the critical hit rules from Warhammer Fantasy Roleplay into D&D.

A self-contained event or series of events in which the PCs do (or have the opportunity to do) something of significance. Attending a royal ball would be an encounter, picking a lock would not. Linking together several encounters is the most basic way to build an adventure.

Opinions and criticism of the game, generally solicited by the GM from the players.

Anything about a PC which can be used to drive the game. For example, a mercenary PC’s rivalry with an NPC merc from another unit would be considered a flag, as it provides the GM with a hook for involving that PC in adventures.

Flavor Text
Descriptive text that doesn’t include any rules elements, most often found in published scenarios.

Slang for the non-mechanical elements of any RPG, such as setting material.

When the GM alters the results of a die roll, usually without the players knowing that they’ve done so. The only form of cheating that’s widely accepted in gaming.

Short for Game Master, the player who guides the other players through adventures, describes the game world and plays all of the NPCs.

GM Fiat
When the GM simply decides the outcome of an in-game event, without rolling dice or involving the rules in any way. Often has a negative connotation.

Game Master Player Character. A PC, not an NPC, controlled by the GM. GMPCs are tough to run well, and all too often they are treated much like pet NPCs, and given unfairly powerful abilities.

Hack and Slash
A play style that focuses on killing things and taking their stuff.

Skipping over something that would normally be played out. For example, if you normally describe each day of travel during a journey, you could handwave that time by saying, “After two weeks of riding, you all arrive safe and sound.” Similar to GM fiat, but generally used to get to the good stuff.

There are two kinds of hooks: background and plot. Background hooks are elements of a PC’s history that the GM can use to tie that PC into the game world, or as fuel for adventures. A plot hook is anything the GM describes to get the PCs involved in an adventure.

House Rule
Any game rule that is added, altered or removed from the original rules.

What the GM does when working without notes or pre-written adventure material, often as a response to something unexpected from the players.

In-character (IC)
Speech and actions performed as if spoken or done by a character, much like an actor in a play.

In Media Res
Latin for “in the midst of things,” a storytelling technique based on starting an adventure or campaign in the middle (usually with an action sequence), rather than at the beginning.

Item Management
Item management encompasses a variety of activities centered around the PCs’ gear, such as tranferring items from PC to PC, buying new stuff and identifying magic items. Most commonly undertaken during downtime.

Live Action Role Playing game. An RPG in which the players are in-character nearly all of the time, and no one is seated around a table.

Any game element that serves primarily to get the PCs involved in an adventure, most often a physical object (prototype robot, magical statue, etc.). For example, the idol in Indiana Jones and the Temple of Doom was a MacGuffin. (The classic example is the Maltese falcon in The Maltese Falcon.)

Marching Order
The order in which the PCs travel when in a confined space, such as a corridor. Most often used in dungeon settings in fantasy RPGs.

Meat Grinder
An encounter or series of encounters that is tougher than usual, making PC death much more likely.

All of the rules elements of an RPG.

Technically, any game-related concerns that are not part of the game itself, but more often used in reference to a player who uses knowledge not possessed by their PC to their advantage.

Background story elements that exist throughout a campaign, often built into the setting. Metaplot elements are often peripheral to a game’s main storyline.

A tiny figure used to represent a character or other game element, most often in conjunction with a battlemat. Miniatures are available both painted and unpainted.

Short for minimize/maximize, a technique where you maximize a character’s abilities in one area while minimizing them in others. Often done by power gamers.

Monty Haul
A play style in which tangible rewards (usually items or treasure) far outweigh the risks involved for the PCs.

An NPC with limited abilities whose only role is to be taken out by the PCs during combat. Mooks usually come in groups, like extras in a kung-fu film.

A player who exploits loopholes in the rules (but does not break them) to build PCs that are more powerful than average. Synonymous with twink.

To make a rules element significantly less powerful (sometimes too much so).

Someone who is new to RPGs.

Non-Player Character. Any character in the game world who is not a PC.

An adventure designed to be played in a single session, and not as part of an ongoing campaign. One-shots often feature pre-generated PCs.

Out-of-character (OOC)
Anything that a player says or does that is not spoken or done in-character, such as asking a rules question.

The group formed by the PCs.

Player Character. Any character that is played by a player, not the GM.

An NPC that receives favored treatment from the GM, often outshining the PCs during the game. Pet NPCs are very frustrating for players.

Play by Email (PBeM)
An online RPG which is played via email, with no face-to-face interaction between the players.

Play by Post (PbP)
An online RPG which is played on a messageboard or forum, with everyone posting their actions for the rest of the group to see.

Technically, everyone involved in playing the game is a player, but the term is most often used to mean everyone but the GM. Each player generally plays a single PC.

Play Style
A distinctive approach to gaming. Every gaming group has its own play style, as does every individual player and GM.

The story that unfolds during an adventure. In RPGs, the plot can start out one way and wind up somewhere very different, because of the actions of the PCs.

Power Gamer
A player whose PC utilizes the rules in such a way as to give them an extra edge, usually in combat and at the expense of non-combat skills.

Short for preparation, all of the activities that the GM does before each session (and when planning out a campaign).

A real-world object that is connected to the game, such as a parchment map that the GM draws for the players to represent that map that their PCs found in the game.

A linear play style in which the players have very few options, so named because much like a train, adventures like this proceed as if on rails. Railroading gets a bad rap, but it can be a good thing in certain situations (at con games, for instance).

Rules As Written. The original, unaltered rules text of an RPG (not modified by house rules, for example).

Rat Bastard Game Master. A GM who fights dirty, but fair. Forcing the PCs to choose between saving the residents of a burning building and capturing their nemesis is something an RBGM would do.

Red Herring
A game element intended to mislead the players, most often one of several possible clues.

Red Shirt
From Star Trek, a friendly NPC whose only real function is to get killed in a dramatic fashion, thus giving the PCs something to fight for. (In the original Star Trek series, when the bridge crew beamed down to a planet, they almost always took a guy in a red shirt — and he was always killed right away.)

Short for retroactive continuity, when previously established game elements (often including the actions of the PCs) are changed after the fact. This can range from “taking back” actions during combat to adding background elements to a character after the game has begun.

RolePlaying Game. A game in which the players take on fictional roles (characters) and take part in a shared narrative, usually guided by a GM.

Rule One
“The GM is always right.” Often called the Golden Rule.

Rule Zero
“Never give the GM ideas.”

Rules Lawyer
A player who knows the rules extremely well, and prefers to stick to them very closesly. Often, rules lawyers use their extensive knowledge of the rules to exploit loopholes that favor their PC.

A discrete event or sequence of events, much like a chapter in a book, that has a definite beginning and end. An encounter is often (but not always) also a scene; an adventure is never a scene.

A series of linked encounters, often played out in one or two sessions, in which the PCs overcome a variety of obstacles. Scenarios can be linked together to form a campaign. (Synonymous with adventure.)

A three- or four-paneled cardboard “shield” that many GMs set up in front of them to prevent the players from seeing their notes, maps and die rolls.

One day/afternoon/night of gaming, which often (but not always) involves playing through a single adventure.

The world in which the game takes place.

Social Contract
The unwritten (often implict, sometimes explicit) rules under which your group operates, covering everything from when and how often you game to how much out-of-character discussion is allowed at the table.

An RPG supplement that further fleshes out an element of the game, most often focused on the PCs. A sourcebook just for warrior characters would be an example of a splatbook. Often shortened to just “splat.”

Splitting the Party
When the PCs split up to tackle two or more things at once.

What is at stake for each of the parties involved in a conflict. Stakes are implict in most RPGs (PC death is at stake in nearly every combat, for example), but some RPGs have rules for setting them.

Short for statistics, the mechanical attributes of a character or item. For example, strength is a stat in most RPGs; the amount of damage caused by a gun would be one of that weapon’s stats.

Story Arc
A series of linked adventures within a campaign, connected by shared plot and/or thematic elements. Resolving a story arc does not resolve the entire campaign (unless it’s the final story arc).

A secondary plot that runs parallel to the main plot. Subplots are often designed so that they can be ignored (or missed) by the PCs.

Another term for a game’s rules.

Table Talk
Any conversation at the gaming table that is not directly related to the game itself, such as quoting Monty Python lines. Excessive table talk can be disruptive.

Total Party Kill. When the entire party of PCs is wiped out in a single instance, most often due to a run of poor die rolls.

A player who exploits loopholes in the rules (but does not break them) to build PCs that are more powerful than average. Synonymous with munchkin.

Wing It
Slang for “improvise.”

The act of creating a setting.


This list was inspired by the Motive Web Design Glossary, which I found out about via Performancing.

If you’ve made it this far, I’ve got a few specific questions for you. Are these definitions long enough? Detailed enough? (I deliberately tried to keep them short and to the point.) And is the cross-linking between definitions useful?