Most role-playing games are conducted like radio drama: only the spoken component is acted. One player, the game master (GM), creates a setting in which the other players play the role of a single character. The GM describes the game world and its inhabitants; the other players describe the intended actions of their characters, and the GM describes the outcomes. Some outcomes are determined by the game system, and some are chosen by the GM. There is a variety of role-playing game in which players do perform their characters' physical actions, known as live-action roleplaying games (LARP).
A genre of video game is also referred to as role-playing games. Although these games do not involve the playing of roles, they take their name from the settings and game mechanics which they inherit from early role-playing games. Due to the popularity of video games, the terms "role-playing game" and "RPG" have both to some degree been co-opted by the video gaming industry; as a result, games in which players play the roles of characters are sometimes referred to as "pen and paper" or "tabletop" role-playing games, though neither pen and paper nor a table are strictly necessary.
Role playing games are fundamentally different from most other types of games in that they stress social interaction and collaboration, whereas board games, card games, and sports emphasize competition.
Role-playing games are a form of interactive and collaborative storytelling. Like novels or films, role-playing games appeal because they engage the imagination. Interactivity is the crucial difference between role-playing games and traditional fiction. Whereas a viewer of a television show is a passive observer, a player at a role-playing game makes choices that affect the story. Such role-playing games extend an older tradition of storytelling games where a small party of friends collaborate to create a story.
While simple forms of role-playing exist in traditional children's games such as "cops and robbers", "cowboys and Indians" and "playing house", role-playing games add a level of sophistication and persistence to this basic idea. Participants in a role-playing game will generate specific characters and an ongoing plot. A consistent system of rules and a more or less realistic campaign setting in games aids suspension of disbelief. The level of realism in games ranges from just enough internal consistency to set up a believable story or credible challenge up to full-blown simulations of real-world processes.
The assumption of roles was a central theme in some early 20th century activities such as the game Jury Box, mock trials, model legislatures, and "Theatre Games". In the 1960s, historical reenactment groups such as The Sealed Knot and the Society for Creative Anachronism began to perform "creative history" reenactments introducing fantasy elements, and in the 1970s fantasy wargames were developed, inspired by sword and sorcery fiction, in which each player controlled only a single unit, or "character". The earlier role-playing tradition was combined with the wargames' rule-based character representation to form the first role-playing games.
Dungeons & Dragons, published in 1974 by Dave Arneson's and E. Gary Gygax's TSR, was the first commercially available role-playing game. TSR marketed the game as a niche product. Gygax expected to sell about 50,000 copies total to a strictly hobbyist market. After establishing itself in boutique stores it developed a cult following.
Another early game was Traveller, designed by Marc Miller and first published in 1977 by Game Designer's Workshop. This was originally intended to be a system for playing generic space-opera-themed science-fiction adventures, in the same sense that Dungeons & Dragons was a system for generic fantasy adventures, but an optional suggested setting called the Third Imperium was detailed with the publication of following supplements and since then this setting has become strongly identified with the game. The changes in this setting over time, especially those involving the Fifth Frontier War as depicted in the Journal of the Travellers Aid Society, constitute the first arguable use of metaplot in a role-playing game.
Dungeons & Dragons was a subject of controversy in the 1980s when well-publicized opponents claimed it caused negative spiritual and psychological effects. Academic research has discredited these claims. Some educators support role-playing games as a healthy way to hone reading and arithmetic skills. Though role-playing has been accepted by many, others continue to object.
Due to the game's success, the term Dungeons & Dragons has sometimes been used as a generic term for fantasy role-playing games. TSR undertook legal action to prevent its trademark from becoming generic.
Games such as GURPS and Champions also served to introduce to role-playing games game balance between player characters; later, Vampire: The Masquerade and similar games served to emphasize storytelling and plot and character development over rules and combat. In recent years, rules stringency has been combined with literary techniques to develop games such as Dogs in the Vineyard that stress player input into a tense situation to give players moral agency in the course of the emerging story.
Competition from computer role-playing games and collectible card games led to a decline in the role-playing game industry. The financially troubled market leader TSR, Inc. was eventually purchased by Wizards of the Coast. To better cope with the economics of role-playing games, and to combat growing bootlegging problems, they introduced a new regime of open gaming, allowing other companies to publish D&D-compatible supplements. Meanwhile, self-defined "Indie roleplaying" communities arose on the internet, studying role-playing and developing several forms of role-playing game theory such as GNS Theory, and critical reflection on role-playing games has become popular in Scandinavia leading even to a yearly academic conference.
In thirty years the genre has grown from a few hobbyists and boutique publishers to an economically significant part of the games industry. Grass-roots and small business involvement remains substantial while larger projects have attracted several million players worldwide. Games industry leader Hasbro purchased Wizards of the Coast in 1999 for an estimated $325 million.
LARPs de-emphasize die rolls and rulebook references. Theatre-style live action role-playing games often use rock-paper-scissors or direct comparison of attributes to resolve conflicts symbolically, while some LARPs use physical combat with foam weapons. LARPs vary in size from a handful of players to several thousand, and in duration from a couple of hours to whole weeks.
Nonetheless, computers and other electronic media are not unknown in role-playing. Online text-based role-playing games use the internet as their medium. Some games are played in a turn-based fashion, whether play-by-mail games using email, or play-by-post games on internet forums. Others are played in a more real-time way, similar to offline games, over  or IRC; these are known as MUDs. Massively multi-player online role-playing games add a graphical component. Finally, some people use internet chat clients or dedicated virtual tabletop software to play what would otherwise be a traditional RPG.
Computer-assisted role-playing games blend elements of traditional role-playing with computer gaming. Computers are used for record-keeping and sometimes to resolve combat, while the participants generally make decisions concerning character interaction. This may include tools used to facilitate traditional pen & paper games to be played over the internet. Such tools may be nothing more than an IRC program, but there is also specialized software which includes built-in functions for dice, character sheets, mapping, and such (e.g., OpenRPG). The upcoming fourth edition of Dungeons & Dragons is slated to make use of an online Digital Tabletop and numerous online tools to expedite play of the game as part of their D&D Insiders program.
Many role-playing games require the participation of a gamemaster (GM), who creates a setting for the game session, portrays most of its inhabitants, known as non-player character (NPCs) and acts as the moderator and rules arbitrator for the players. The rest of the participants create and play inhabitants of the game setting, known as player characters (PCs). The player characters collectively are known as a "party".
During a typical game session, the GM will introduce a goal for the players to achieve through the actions of their characters. Frequently, this involves interacting with non-player characters, other denizens of the game world, which are played by the GM. Many game sessions contain moments of puzzle solving, negotiation, chases, and combat. The goal may be made clear to the players at the outset, or may become clear to them during the course of a game.
Some games, such as Polaris and Primetime Adventures, have distributed the authority of the GM to different players and to different degrees. This technique is often used to ensure that all players are involved in producing a situation that is interesting and that conflicts of interest suffered by the GM are avoided on a systemic level.
Games rules determine the success or failure of a character's actions. Many game systems use weighted statistics and dice rolls or other random elements. In most systems, the GM uses the rules to determine a target number though often the targets are determined in a more principled fashion. The player rolls dice, trying to get a result either more than or less than the target number, depending on the game system. Not all games determine successes randomly, however; an early and popular game without random elements is Amber Diceless Roleplaying Game by Erick Wujcik (1990).
Most systems are tied to the setting of the game they feature in. However, some universal role-playing game systems can be adapted to any genre. The first game to feature such a system, GURPS, is accompanied by a number of sourcebooks which allow games to be created in different genres. The d20 system, based on the older role-playing game Dungeons & Dragons, is used in many modern games such as Spycraft and the Star Wars Roleplaying Game.
In practice, even universal systems are often biased toward a specific style or genre and adaptable to others. For example, although the d20 system has sourcebooks for modern and futuristic settings, most published d20 system material stays within Dungeons & Dragons' combat-focused fantasy milieu.
Attributes are statistics all characters possess: strength, agility, and intelligence are common examples. These are ranked, often on a numeric scale, so that a player can gauge the character's capabilities. For example, a character's strength rating could be used to determine the likelihood that the character can lift a certain weight.
Skills are abilities that only some characters possess, such as negotiation, horseback riding, and marksmanship. Game systems often define skills that are genre-appropriate. For example, fantasy settings generally include magic skills, while science-fiction settings may contain spaceship piloting skills. However, some skills are found in several genres: a medieval rogue and a Wild West outlaw may both be very proficient at throwing knives, and a skill labeled "diplomacy" may benefit ancient Greek patricians or industrial tycoons of the 19th century equally well.
Character motivations are things that the character will fight for. The Riddle of Steel's Spiritual Attributes, Burning Wheel's Beliefs and The Shadow of Yesterday's Keys are such features. They might reveal secrets the character has kept, aspirations they hold, or other characters they care about.
Before play begins, players develop a concept of the role they would like to play in the game. They then use the game system's character creation rules to form a representation of their characters, in terms of game mechanics. The character's statistics are recorded on a special-purpose form called a character sheet. Some systems, such as that of Feng Shui, require characters to choose from a set of pre-built template characters with only a small amount of customization allowed. Others, like the d20 System, use character classes to define most character concepts, but allow some freedom with the statistics within those classes. Still others, such as GURPS, allow the player to create their own character concepts by freely assigning statistics.
Game statistics are not a substitute for a character concept. For example, one Wild West gunfighter may become a quick drawing revolver marksman, whereas another with similar game statistics could be a mounted rifle expert. Many systems take this into account, requiring statistics to be described, such as Dogs in the Vineyard's Traits and Possessions.
Template-based systems have the advantage of easy and quick character creation. It also provides the GM with the means to spend less time approving each character for play. The sacrifice is in flexibility and concept. Templates are essentially pre-built characters that are balanced against each other and pre-approved by the game companies.
Class-based systems give slightly more freedom but still require a player to choose from a set number of roles for their character. The character's powers are generally set by the character class, but the specific statistics are assigned by the player.
Character point-based systems allow complete freedom of concept. The downside is that, in many cases, character creation is much more complex, making the GM spend a lot more time examining and approving each character concept.
A few games allow free-form character creation. Characteristics are simply assigned as a player sees fit, and the final result is submitted to the GM or group for approval. Free-form character creation can be implemented in any game system, but is only rarely the prescribed or assumed method.
Campaign settings exist for almost all genres of fiction; however, because the world's most popular role-playing game, Dungeons & Dragons, is part of the fantasy genre, fantasy is also the most played role-playing genre. RPGs of the fantasy genre are sometimes collectively called "Fantasy role-playing games" ("FRP").
The use of the term "world" in describing a campaign setting is loose, at best. Campaign worlds such as the World of Greyhawk detail entire cosmologies and time-lines of thousands of years, while the setting of a game such as Deadlands might only describe one nation within a brief segment of alternate history.
There are three primary types of campaign setting. The first exists in genre- and setting-specific role-playing games such as Warhammer or World of Darkness which exist specifically within one setting. The second type of setting is for games that have multiple settings such as modern Dungeons & Dragons or those that were developed specifically to be independent of setting such as GURPS. The final type of setting is developed without being tied to a particular game system. Typically this last sort are developed first as stand-alone works of fiction, which are later adapted to one or more role playing systems such as the Star Wars universe or Middle-earth.
The range of genres represented by published settings is vast, and includes nearly all genres of fiction. While role-playing's roots began in fantasy, science fiction has been used in settings such as Traveller, horror formed the baseline of the World of Darkness and Call of Cthulhu and Spycraft was based in modern-day spy thriller-oriented settings.
The largest publisher of role-playing games is Wizards of the Coast, a wholly owned subsidiary of Hasbro and publisher of Dungeons & Dragons, the D20 Star Wars RPG, and a number of smaller D20 titles. Most analysts give White Wolf the second largest industry market share, with the company itself claiming an average market share of 22% since 1991 , and the highest share in live-action games. Most role-playing game publishers are privately held companies and do not release sales figures, making precise estimates difficult. There has been no publicly available, systematic examination of point of sale data, limiting further estimates to a rough consensus between industry analysts whose conclusions are often controversial.
Market research conducted at Wizards of the Coast in 1999-2000 indicated that more than 1.5 million people played D&D on a monthly basis, and about 2 million people played all tabletop RPGs combined on a monthly basis. The success of the 3rd Edition of Dungeons & Dragons likely resulted in an increase in those totals. These figures for play are substantially larger than the figures for sales. In 2006, non-Dungeons & Dragons tabletop RPGs in the upper echelons of sales typically generated between five and ten thousand unit sales. Most commercially published RPGs are small press products, having less than a thousand units sold. The technology of print on demand is strongly used in RPGs, since it reduces run costs for the typical small print runs.
The standard business model for successful RPGs relies on multiple sales avenues:
Typically, RPG publishers have a very long life cycle once they manage to generate an initial successful game. TSR, the initial publisher of Dungeons & Dragons was an independent entity until 1997 when it was acquired by Wizards of the Coast, who was subsequently acquired by Hasbro in 1999. Many of TSR's contemporaries remain in business as independent publishers. The core design group of a publisher is often kept as a team within the new company for the purposes of continuity and productivity, though layoffs are common after such mergers and acquisitions. For example, Wizards of the Coast experienced multiple layoffs in the wake of acquiring Last Unicorn Games and after its own acquisition by Hasbro.
Indie games are produced by a self-identified independent games community, or individuals who identify with that community. Generally they are self-published or published by a collective group of small publishers. The indie role-playing game community often produces games with signature and idiosyncratic character. Some indie publishers often eschew the three-tier distribution model and sell directly online and at conventions, or directly to stores, but many do use distribution services. The line between "indie" publishers and "mainstream" publishers is hazy at best. Varying definitions require that commercial, design, or conceptual elements of the game stay under the control of the creator, or that the game should just be produced outside of a corporate environment, or be distributed without dependence on the industry's three-tier retail structure.