An "emergent narrative" or "procedural narrative" is any Video Game storyline that is not written ("embedded"note ) into the game by its developers, but emerges from the player's interactions with various gameplay subsystems. More specifically, the player recognizes and interprets events that occur within the game space as part of an ongoing narrativenote and projects their own emotions onto the in-game character constructs. Because emergent narratives are thus player-driven, rather than developer-driven, and because computers generally cannot recognize narratives as easily as humans do, they tend to be a lot messier than the carefully curated embedded narratives, and it is hard to ensure that every player will experience one, in the first place. On the other hand, because our brains are so well-adapted to telling stories, the inherent messiness of emergent narratives tends to get curated and to diminish in subsequent retellings.
As usually defined, emergent narratives specifically concern plots that arise from repeated player-game interactions (player-environment, player-NPC, NPC-NPC, etc.), but not from player-player interactions in multiplayer modes. This therefore excludes collaborative story-telling and role-playing of every kind (tabletop, LARP, online, as well as "story games"), even though these feature emergent narratives trivially, because it's their main goal. Also excluded are non-interactive narrative generators, from the 1977 Tale-Spin, to This Very Wiki's Story Generator. Video games designed to facilitate emergent narratives often have following featuresnote :
- Procedural Individuals. As players, we tend to look for "main characters" in every narrative (although they are technically not required) and to develop an emotional attachment to them. Games with emergent narratives typically use Procedural Generation to create characters that are human(-like) or, at least, uniquely recognizable in a way that allows us to project our emotions onto them. But the less characterization they are front-loaded with, the easier said projection becomes, so making a character just enough of an individual is a fine balancing act.note
- Persistence. For a narrative to emerge, both the characters and the game world they inhabit must persist and evolve throughout the game. For characters, this means that they should a) be able to survive for longer than a single deployment, and b) accrue individuating traitsnote and carry them over from level to level. For the game world at large, this typically requires some kind of Choice-and-Consequence System, unless it is fully simulated.
- Interlocking Systems. Emergent narrative, just like Emergent Gameplay, cannot occur unless the simulation contains a large number of consistent and interacting subsystems, resulting in a combinatorial explosion of possible game states and thus ensuring that every playthrough is different from the last.
- Intentionality. The thing that sets games apart from full simulations is the power that the player has to direct them. For the player to develop a sense of responsibility for and co-authorship of the emergent narrative, they must be able to envision their intended narratives and to work towards them with the mechanics they have access to.
- Uncertainty. Because narrative tension comes from not knowing what happens next, the player's complete control has to be moderated by either plain randomness (of events or outcomes) or artificial intelligence, which allows the characters to pursue their own agendas in opposition to the player (or at least to seem like they do).
Note that academic game studies further subdivide emergent narratives into "player-driven" and "procedural", with the former consisting only of immediate player actions and the player's interpretation of them; the latter, meanwhile, is comprised of the in-game events that have been built in by the devs but occur at runtime according to procedural logic, rather than to a writer's direction. The distinction is very fluid, however, so this trope basically blends them together. Lastly, there is also an ongoing research field of "computational narratives", where Video Game A.I. actually tries to parse and to direct in-game events and player actions as a dramatic narrative thread.
Compare Emergent Gameplay, which has similar requirements but concerns the act of play, rather than the act of storytelling (most Immersive Sims, for instance, feature a lot of emergent gameplay, but have embedded, if branching narratives). Contrast Story Branching; see also Sliding Scale of Gameplay and Story Integration and other Interactive Storytelling Tropes.
Examples (no Troper Tales, please!):
- Middle-earth: Shadow of Mordor features the Nemesis System, which dynamically populates and shuffles the enemy orc social hierarchy based on Talion's actions. Each orc is procedurally generated with random personality and appearance traits, remembers and references previous encounters with Talion (if he survive them), and gains further abilities and individuation (like nicknames) as he climbs the ladder, especially if he manages to kill Talion. Later in the game, Talion learns to brainwash orcs and then subtly orchestrate their rise to power from the shadows, producing highly memorable From Nobody to Nightmare narratives.
- FTL: Faster Than Light's story follows you, a starship captain, with valuable information for your allies who are on the losing side of a rebellion, while the Rebels pursue you. During your journey, you accumulate currency, crew, equipment, and ship upgrades from various "beacons", or waypoints. Sectors are randomly generated, and what occurs at each beacon is usually a Random Event. Each event and even an empty beacon will describe some occurrence, the outcome of which you usually have a hand in. Seen all together, the events form a narrative of how you went from a basic ship and skeleton crew to ready-to-face-the-Rebel-flagship. (Or how you failed to.) Your journey can go one way in one playthrough and be significantly different in the next. The only story elements that definitely occur are those at the very beginning and at the very end (assuming you make it that far).
- The Sims runs on this: the player is able to create characters (with appearances and personalities which are determined differently depending on the game), and then design a house, and everything from then on is up to them. They could try and make their sims rich and successful by doing the 'right' things and advancing in their careers, could set up a number of families and play out a soap opera situation, or could just try and kill them in various imaginative ways - the player themselves creates the story.
- Game Dev Tycoon is about your life as an indie video game developer in the 80's. As you make your way through the years, you can build a huge a company with several employees and a backlog of hit games, or crash and burn after years of failed experiments and bad investments. You ultimately decide what type of games you want to make, what systems you want to support, and if you want to create long-running franchises or new properties. The legacy that you leave behind in the video game industry can wildly vary on a playthrough-by-playthrough basis.
- Both Crusader Kings games simulate hundreds of artificially intelligent characters (mostly nobles and royals) across many generations, with heirs being procedurally generated based on which dynastic marriages occurred, with or without the player's intervention. They also simulate a vast number of environment factors, from geography to religion, ensuring that every playthrough has literal centuries of fresh dynastic drama.
- XCOM: Enemy Unknown is unusual in that its procedurally generated individuals (your alien-busting squad) are not artificially intelligent. However, they are just individuated enough (through appearance, names, nationalities, and, eventually, classes, call signs, and Psychic Powers) and their battles are sufficiently random that most players become emotionally invested in their advancement and survival, and have at least one story to tell about that one soldier who survived against all odds again and again to save the day in the final mission.
- Rebuild uses random character generation and little bits of characterization (survivors give feedback one what they found, congratulate each other on getting better at scouting/killing/leading/etc.) to make it that much harder when one of them dies.
- Dwarf Fortress excels in this. At world creation, a detailed history is procedurally generated for the whole world, which continues as the player creates their fortress. Each action by the player is recorded in the world history, which may affect later playthroughs in the same world. You can even start a fortress on top of a previously abandoned one, or visit it in Adventure Mode. But beware, as whatever caused the doom of that fortress is probably still lurking around.