The Outer Worlds Vertical Slice

tim-cain outer-worlds obsidian vertical-slice game-development production unreal-engine

Abstract

Problem: What does a vertical slice actually look like for a major RPG, and how does a team produce one under tight constraints?

Approach: Tim Cain presents the actual vertical slice milestone video that Obsidian sent to publisher Private Division in September 2017, one year into The Outer Worlds' development, with commentary on what vertical slices are and how the team pulled it off.

Findings: The Outer Worlds team built a polished, shippable-quality vertical slice of the Roseway area in just one year — while simultaneously learning Unreal Engine 4 and spinning up a brand-new IP. The slice was so good it shipped as part of the final game. The team cleverly hid incomplete features (limited companions, no crafting) through smart level design rather than showing gaps.

Key insight: A great vertical slice doesn't need every feature — it needs to hide what's missing so well that no one notices, while showcasing what exists at shipping quality.

Source: https://www.youtube.com/watch?v=ZjI-iTy11uM

What Is a Vertical Slice?

Tim begins by defining the vertical slice in the context of his production stages framework. A vertical slice is a playable section of the game that looks and plays like the final shipping product. It sits between two earlier milestones:

  • Prototype — tests game mechanics with placeholder art (gray-boxed levels, T-posed characters, no final visuals)
  • Beautiful Corner — shows final art quality but has no gameplay (no creatures, no combat, no interactable objects — just a walkable environment)

The vertical slice combines both: a playable map with real mechanics and polished visuals. It doesn't need to show every feature or every piece of art, but what it does show must look and feel like the shipped game.

The Outer Worlds Context

The vertical slice Tim presents was made under remarkable constraints:

  • One year into development, two years before shipping
  • The team had to learn Unreal Engine 4 from scratch during that year
  • They were building a brand-new IP ("Project Indiana") where not everything had been decided at the start
  • The milestone was sent to Private Division (the publisher) as Milestone 9 in September 2017

Tim emphasizes how impressive this was — he's seen teams that couldn't achieve this quality after two, three, or even four years.

What Was Shown (and What Was Hidden)

The vertical slice takes place in Roseway on Terra 2, where the player investigates a cut-off distress call. The slice was so polished that it shipped as the actual Roseway area in the final game.

What was ready

  • Guns, creatures, particle effects, environmental art, buildings, and map transitions
  • Multiple playable archetypes (combat, leadership, dialogue, stealth)
  • Tactical Time Dilation (TTD)
  • Companions Ellie and Felix
  • Dialogue trees with meaningful consequences
  • Environmental storytelling and humor

What was missing (and how they hid it)

  • Only two companions (Ellie and Felix) — they simply prevented the player from boarding The Unreliable, which is the only place you can swap companions
  • No crafting system — by blocking ship access (where the crafting table lives) and placing no crafting tables in Roseway, the absence was invisible
  • Hair wasn't ready — only Ellie had hair; all other NPCs were bald
  • UI was incomplete — some mechanics had only been coded a week or two before the deadline

The key lesson: they didn't apologize for missing features. They designed around them so the gaps weren't noticeable.

The Four Archetypes Demonstrated

The vertical slice showcased four distinct play styles, narrated by designer David Williams:

Combat Archetype

  • Heavy machine gun (high damage, large magazine)
  • Streamlined called shots for easier use
  • Revised TTD allowing shooting and ability use during slowdown
  • Fast, brutal melee combat
  • Visceral enemy death feedback (fire, electricity, explosions)

Leadership Archetype

  • Two companion abilities: Inspiration (increases ally damage) and Determination (armor boost)
  • Leadership skills could be mixed with stealth, called shots, melee, and other abilities

Dialogue Archetype

  • Manipulating NPCs through conversation (intimidate, persuade)
  • Solving quests without combat — persuading a security team to leave rather than fighting
  • Meaningful consequences: the player could convince the lead scientist Anton to abandon his work or even kill himself

Stealth Archetype

  • Awareness level indicators for nearby NPCs
  • NPC barks and audio cues as stealth tools
  • Completing objectives without being seen
  • Ambush attacks for massive damage bonuses when transitioning from stealth to combat

Key Takeaways

Tim's commentary highlights several production lessons:

  • A vertical slice is a publisher-facing milestone — it proves your team can ship a game at the expected quality level
  • Smart scoping matters more than completeness. Show what works; hide what doesn't.
  • One year is enough to build something remarkable if you have the right team
  • The fact that Roseway shipped largely as-is from the vertical slice speaks to the quality bar the team hit early

Tim closes by noting this was "Milestone 9" — meaning the team had hit 8 milestones before this, each building toward this moment. The vertical slice wasn't a lucky break; it was the culmination of a disciplined production process.

References