Role-Playing Games (aka RPGs) have seen different twists and takes on the genre since inception. In summary, in an RPG, one or more players take up the roles of fictional characters, who find themselves in fictional settings or worlds controlled by a system of rules or guidelines that define outcomes. These characters take active roles in driving the narrative forward, usually through real-life acting or structured decision-making. Usually, the storyline is intentionally left loose or open-ended, and how characters act or perform in events, the narrative structure, and how they cope with character traits or limitations are what fill in the empty spaces. Unlike more traditional forms of fiction, Role-Playing Games are considered interactive or collaborative storytelling, depending on the sub-genre.
The roots of RPGs are found in traditional children's games of make-belief. However, RPGs develop this concept further with an element of continuity and added sophistication. A feature such as a game master, who monitors the progress and rule-keeping, is one example. Also, the level of reality is enhanced through ongoing campaign modes with enough internal consistency starting from a mimimum necessary to make the story plausible all the way to extremely elaborate simulations.
The most traditional form of RPG is called Tabletop RPG. This and Pen & Paper RPG usually occur in the form of social gatherings. The game master usually decides the rules and theme/setting beforehand. If it's a one-time standalone game, he may also create the characters as well. Throughout the game, the game master describes the fictional world, inhabitants, and the next step in the narrative based on the players' actions and interactions. In some cases, the game system defines the outcomes, whereas in others the game master does. Players must choose or are assigned one character and stick to it. Systems of rules and game settings vary greatly from one game to another. Some lean heavily towards game mechanics and combats, while others emphasise plot and character interaction more. The latter tends to go by the name Storytelling Games. Some use dice as a randomising agent. Some use pen(cil) and paper, hence the name Pen & Paper RPG, amongst other props depending on game style.
The social element in RPGs was taken one step further with the introduction of LARPs (Live Action Role-Playing) that usually plays out in a way akin to improvisational theatre. Players will often cosplay as their character of choice and utilise props. Actions are acted out in a make-believe style. The game's imaginary world is set in the real environment, and at times, the venue may be decorated for desired effect. When conflict takes place, this is either resolved by simple games such as rock-papers-scissors or comparison of tributes. Other LARPs take a more direct approach with actual combat utilising airsoft guns and/or foam melee weapons.
LARPs allow for bigger numbers of players participating at one single time. There are instances when this goes up to 1000+ players. In the case of large numbers, different physical spaces might be utilised by different sub-groups, allowing for concessions in looser narrative and game sessions being managed in more distributed ways.
The latest addition to the RPG family are the ones that come in electronic media format, or known simply as video games. The original format in this sub-genre is multi-player text-based MUDs. Later on, with the advances in game design and technology, more elaborate RPG video games with avatars and fully-developed computer graphics-based worlds were introduced. Some of the latter either rely on single-player or a small team management, while others are known as Massively Multiplayer Online Role-Playing Games (MMORPG). While these games share a lot of features in common with tabletop predecessors, there is a greater emphasis on statistical mechanics that allow for character features and capabilities' enhancement.
Other games such as trading card games and wargames also tend to encompass role-playing elements, but this, more often than not, doesn't occupy central focus. That's why bespoke games are not primarily considered as RPGs.
Nowadays, role-playing simulation has also penetrated academia and some forms of specialised training as well as forms of research and education that offer an added element of verisimilitude.