How To Gate Non-Linear Stories

tim-cain narrative-design non-linear gating fallout arcanum outer-worlds player-agency quest-design essential-npcs

Abstract

Problem: In non-linear games, how do you ensure story events happen in a meaningful sequence without destroying player freedom?

Approach: Tim Cain draws on his experience designing Fallout, Arcanum, and The Outer Worlds to explain gating mechanisms — blocking access to areas, NPCs, quests, or items — and why designers (not programmers) should own this problem.

Findings: The best non-linear stories minimize forced ordering. When gating is necessary, it should feel organic (collecting items, completing quest chains, discovering locations) rather than artificial (essential NPCs, invisible walls). The number of story acts should fall between Fallout's 3 and Arcanum's 27, and only the final villain confrontation truly needs to come last.

Key insight: Gate as infrequently as possible. Every gate you add chips away at non-linearity — if you're adding too many, you're making a linear game and should question whether you need a game at all, or a movie.

Source: https://www.youtube.com/watch?v=qm2qwgVwf1A

This Is a Design Task, Not a Programming Task

Tim emphasizes that story gating belongs at the design stage, specifically narrative design. Programmers may build the tools that enable gating, but deciding where and when to gate is a designer's responsibility. Leaving it to programmers is a mistake.

Minimize Ordered Steps

The first principle: make your story require as few ordered steps as possible. Let the player do A, B, and C in any order.

Fallout had three acts — get the water chip, destroy the mutant army, kill the Master. The intended design was to do A first, then B and C in any order. But players discovered they could skip the water chip entirely and go straight to B or C in either order. Three steps, minimal ordering, and it worked.

When You Must Gate: Make It Organic

If ordering is truly necessary — usually for the villain confrontation — the gating should feel natural rather than arbitrary. Common mechanisms:

  • Keys or access codes that aren't available until a certain point
  • Item collection — gather components that must be assembled (the "collect 10 jewels" pattern)
  • Quest chains — completing one quest reveals the next NPC or location
  • Area discovery — you need to learn where something is before you can go there

The Arcanum Example

Arcanum's story required reaching the Void to confront the villain. Getting there required a device → which required a chain of quests → which required meeting specific NPCs → which required discovering their locations. The player could go anywhere in the world freely, but finishing the story required completing this chain. It didn't feel linear even though it had an underlying sequence.

The Problem with Essential NPCs

Essential NPCs — characters the player literally cannot kill — are a common but lazy gating mechanism. Tim hates them. They violate player agency: if you can't kill an NPC, why does the game have combat? What's special about this person?

Better Alternatives

  • Temporary essentiality: Mark the NPC as unkillable until they give you what you need, then remove the protection. Fallout did this with the Overseer — he couldn't be killed during the game, but at the ending when he exiles you, the protection drops and you can take out your frustration.
  • Remote contact: The NPC communicates via hologram, phantasmal image, or other means that make them physically unreachable. You can interact but can't kill them.
  • Backup information paths: If you kill the NPC, you can still get what you need through alternate means:
    • They drop a journal with the information
    • Better yet, the journal points to where they found the information (e.g., "I learned the passphrase from the Oracle in the Skuzblat Dungeon"), sending you on an alternate quest
    • The alternate path only becomes available because the NPC is dead (e.g., they had a key to the dungeon)

The goal: the player always has agency, but they still end up doing things in roughly the order you predicted.

Only Gate When You Must

Tim's strongest advice: only gate if you have to, not if you want to. Designers often think "the story unfolds better this way," but a game's story is ultimately the story the player tells themselves. If you're forcing a rigid sequence through multiple linear gates, you might be better off writing a movie or a book.

Finding the Right Number of Acts

  • Fallout: 3 acts (a little too few)
  • Arcanum: 27 acts (a little too many)
  • The ideal is somewhere between those extremes

Acts don't need to be linear — they need to be distinct. In a well-designed non-linear game, only the final act (the villain confrontation) truly needs to come last. All preceding acts should determine what tools, knowledge, and options the player brings to that finale — whether that's talking their way through, bypassing the villain entirely, or entering the nuclear launch codes under his base.

The Core Philosophy

Make your non-linear story as non-linear as possible. Use gating mechanisms as infrequently as possible. Every time you add one, ask yourself: "Do I have to do this?" If you're asking that too often, you're no longer making a non-linear game.

References