In their most simple form, a tabletop roleplaying game (TTRPG) is a form of storytelling where an individual or group participates in a story that is in some way reactive to decisions that they make.
Perhaps one of the simplest versions that many of us have played are “pick a path” style stories, where at certain points we are given options to choice, or “pick”. These choices then lead to a different “path” for the story to take.
The appeal is obvious: YOU are effectively choosing how the story ends, not the author (although in the case of pick a path books, the number of potential endings is necessarily finite).
To flip to the more complex end of the spectrum, we need to look no further than the most well known TTRP, Dungeons & Dragons. In recent years, Dungeons & Dragons has undergone a significant resurgence, that has only been further boosted by popular TV shows, such as Netflix’s “Stranger Things”.
While there are countless other alternatives systems to D&D, the core for a significant majority remains the same. A game usually consists of a Game Master and a small group of people. The Game Master is a mixture of story-teller and referee of sorts. The group usually assumes the roles of their chosen characters. Depending on the game system, these could be Lord of the Rings style fantasy tropes, Blade Runner-esque future noir detectives or criminals, 80s style Speilgergian kids on bikes, or a squad or Roman Legionairres. There is no limit to the possible scenarios and settings.
The Game Master presents a situation or call to action to the group and the group decides, in character, what to do. While the Game Master may have particular story points they wish to advance, how that occurs (or if they occur at all) is up to the players.
At its core, then, a tabletop roleplaying game is a collective storytelling experience (although some can be played alone). Usually the GM is not playing AGAINST the characters, they are there to assist their journey and enjoyment through the world they have created. Whether that is through comedy or drama, horror or war.