Linearity in adventure design describes how players get from point A to point B. While you can structure your adventure as either linear or nonlinear, in this section we're going to talk about why most adventures ought to be structured in a nonlinear way, to avoid the cardinal sin of railroading.
To "railroad" an adventure means to design it around specific predetermined outcomes. Instead of creating a fictional space in which your players can make meaningful choices that result in emergent storytelling, you design a story with beats that your players have to hit in order to progress. And when they don't hit those beats, you retrofit the fiction to force those outcomes.
When you railroad players this way, you take away their agency. Railroading is "the players will find the treasure and then seek the aid of the wizard and then kill the dragon and I as a GM will thwart any attempt to derail those outcomes I’ve predetermined for them." Nobody wants to be railroaded, because to play in a game that is railroaded is not to play a game at all.
A railroad is different than a linear adventure, however. In a linear adventure, players don't have a choice as to the order in which they go from scene to scene. This definitely restricts their agency, but it doesn't go so far as to negate all their choices. This type of adventure is actually harder to set up than a nonlinear adventure.
Player Agency in Linear Adventures
For example, in the OSR+ one-shot Fear the Light, the party consists of a bunch of cowboys who are looking to get their revenge on a villain called the Ten Cent Man.
There are four scenes in the adventure, divided into two acts:
- a card game;
- a downtime en route to Dead Man's Butte;
- an encounter in Dead Man's Butte itself;
- and the final showdown with the villain.
Anatomy of Fear the Light
These scenes progress from A to B to C and there isn't a way to bypass them or play them out of order. In the first act, players exercise agency by building aspects of the Ten Cent Man through the Game of Faro, which immediately impacts the narrative when they confront him. The PCs could up and leave the poker table and refuse to engage with the patrons of the Blood Bucket Saloon, but the point of playing Fear the Light is to immerse yourself in a mythological Wild West, where tense conversations lead to standoffs in gritty saloons. Thus the players implicitly accept that the boundary of play in act 1 is the Blood Bucket Saloon. While the adventure does account for other locales in the vicinity of the saloon (in case the duel with the Ten Cent Man spills out of the saloon), these locations are not scenes unto themselves but points of interest within the card game scene.
Meaningful Choice in Linear Games
Despite the linearity of the scenes in Fear the Light, players can still make meaningful choices within each scene that impact how the rest of the scenes play out. The PCs don't have to duel the Ten Cent Man or defeat his cronies—it's entirely possible to turn them against the Ten Cent Man and pick them up as NPCs, for example. This would affect how the subsequent scenes play out.
Rather than player agency deriving from where the PCs go and where they could have gone otherwise, player agency derives from the choices they make within scenes that enable them to fulfill their narrative destinies: Do they end up killing the villain in the final showdown, or convincing the villain to join them? Do they save Bordertown in time, or is it ravaged by the Daybreaker? These all result in different outcomes that may or may not result in narrative fulfillment for the PCs.
Adventure Hooks in Linear Adventures
The adventure hooks in a linear adventure, instead of cluing players into the existence of other scenes, clue players into the ways in which their choices can affect how subsequent scenes could play out.
All in all, adventure hooks in linear adventures are about revealing possibilities within scenes. One way to design linear adventures is to think of each scene as containing secret "subscenes" that can be opened if the players so choose, and these possibilities are what the adventure hooks point to.
Nonlinear adventures, on the other hand, are made up of scenes structured more like a web than a straight line. Instead of scene A leading to scene B leading to scene C, players can go from any scene to any scene in any order they see fit.
Consider the above diagram in the context of the adventure Monsters in Merovia (MiM). In this adventure, there are six scenes:
- The Constabulary
- The Church
- The Bakery
- The Tavern
- The Old Mill
- The Docks
Conveniently, all the scenes in MiM represent physical locations, but as we will see as we explore the types of scenes, a scene can be structured as an event as well.
Scene Anatomy of Monsters in Merovia
In MiM, the players accept the premise that the boundaries of play is the town of Glenluce because the adventure is a short consisting of three sessions that centers around the mystery that happens there.
If this were a longer campaign, it's possible the six scenes in Glenluce would represent only a single adventure in the campaign, and so the diagram above would only be one among many the GM could prepare covering other areas of the campaign world that the players might explore. In that case, some of the adventure hooks within scenes might point to scenes outside the immediate Glenluce adventure (more on that in types of adventure hooks).
When the town Glenluce is presented to the players at the start of the adventure, the GM might describe only the things they can see upon entering the town: a barely paved road leading to a dilapidated but boisterous tavern, a conical church made of stone behind it, and off in the distance, cellar doors in the middle of a clearing that leads to the constabulary's underground bunker.
The players immediately have a choice as to what to explore (and we know those three locations map to three specific scenes). In fact, they can ignore the locations that are immediately apparent and stumble upon the others farther away in the town (the Docks, the Old Mill, the Bakery). All of these points of interest are available to them in any order.
Adventure Hooks in Nonlinear Adventures
In this structure, the adventure hooks to be discovered within each scene function as clues as to where to go next. This is why we need to place at least three hooks to other scenes in any given scene. Multiple hooks may point to the same scene (to emphasize that scene's importance).
As you can see in the above diagram, adventure hooks are a way to "traffic" the PCs through the adventure. While players don't want to be railroaded by the adventure, they do want to be guided through it, and so adventure hooks reinforce (or dispel) their suspicions about what in the fiction is to be uncovered, and what in the fiction might advance the narrative.
Adventure Hook Anatomy in MiM
Consider the adventure hooks in these two scenes of MiM:
- The Tavern: At this location, the players can rest and carouse. There is also an encounter with ghouls that occurs if there's enough of a crowd present (they arrive at peak hours when most townsfolk are there).
- The druid Stahl is giving a sermon later that night at the Church (The Church).
- The townsfolk whisper about the town guard Jacob, who has been hoarding the sick in the constabulary (The Constabulary).
- The barmaid speaks fondly of Elder Aidan, whose bread has kept the town fed during this ordeal (The Bakery).
- Fishermen nearby speak skeptically of a foreign vessel newly arrived at the docks (The Docks).
- The Church: At this location, the players can seek the wisdom of the traveling druid Stahl or his acolytes. If they come at night, the druid Stahl gives a fiery sermon to the townsfolk, imploring them to atone for their sins so as to stop the blight.
- His attempt to sacrifice the sick to get the gods to renew the harvest is his way of compensating for the nonfunctioning grindstone in the Old Mill (The Old Mill).
- The townsfolk mention the foreign merchant Karn and his sales of medicine at the docks (The Docks).
- And Faolagan, distributing communion wafers, complains of Elder Aidan's absence at the bakery and his ambitions to take over the enterprise (The Bakery).
Some of the adventure hooks in both scenes overlap (cluing players to the same scene), and this is intentional, because we want to create redundancy for when the players inevitably forget about the point of interest that the adventure hook highlights, or when they fail to discover the hook for lack of thoroughly investigating the scene.
By structuring the adventure as a web of scenes instead of a straight line, the players get to be in charge of how the narrative unfolds, because they choose where to go next, informed by the adventure hooks they uncover in each scene.
Grappling with What Ifs
Players typically like to follow a trail because a trail suggests something is out there to be discovered—the whole sense of adventure in roleplaying games comes from the players' curiosity about the world. We create redundancy in scenes by having adventure hooks in each scene point to other scenes, to continually remind players what scenes exist and why they might be important.
What If: The Players Ignore My Hooks?
It's OK if a scene might get ignored by the players: you can always repurpose its content into another adventure, or move its discoveries to other scenes. You can also create types of scenes that present themselves by GM fiat (floating scenes) or that are inaccessible to the players until they fulfill some objective (gated scenes). This is discussed in more detail in the section types of scenes.
What If: The Players Exit the Adventure?
When you present the adventure to the players, you also present the boundaries of play.
In a one-shot or a short, those boundaries probably remain the same from session to session (likely because there are only one or two adventures to explore and a handful of scenes in each). In a campaign, those boundaries may change over time, but they should still be apparent from session to session: this adventure takes place in the frozen north, or that adventure takes place in a particular dungeon, or perhaps there are three adventures you've string together with events in the overworld, and all the scenes across those three adventures are accessible to them for the next X sessions.
Take a Step Back & Re-Assess
If players decide they want to explore something outside the boundaries of your adventure (they choose to get in their airship and fly away from the frozen north, ignoring the famine in the land they agreed to investigate in the previous session), it's also OK to end the session there, and have a discussion about what the table is actually interested in doing. After all, you're a player too, and what you want to run is as important as what they want to play.
What If: The Players Find the BBEG's Lair Too Soon?
Part of this problem is solved by the type of scene the BBEG's lair is to be found in (the scene should likely be gated), but the larger problem is that this sort of thinking is outcome-oriented.
That is, what you're really worried about is "what if the players find and defeat the badguy before I want them to." It's entirely possible, for example, for the PCs in MiM to discover who the villain is and capture or defeat them as early as the first scene in the adventure.
When that happens, the adventure is no longer about defeating the BBEG, and it's up to you to assess the scenes in the adventure and adjust them accordingly.
Thinking On Your Feet
For example, in MiM, if the villain is defeated early, that doesn't mean the adventure is over: the villain in this adventure was influenced by a magical artifact (the grindstone in the Old Mill), and it's through the power of this artifact that the villain is able to control the roving ghouls that plague the town of Glenluce. The PCs still need to cleanse Glenluce of this plague and destroy the artifact.
With a captured villain, the PCs can now interrogate them and learn their grand scheme, which is an opportunity to put in place a clock that ups the stakes of the adventure: perhaps with no one to control the ghouls, they will overrun Glenluce, and the rest of the adventure becomes a race to get into the Old Mill and destroy the artifact amid the mounting horde.