Build a vertical slice — prove one polished slice at target quality
GDC-L1-PROD-000301
Statement
Before scaling to full production, build a vertical slice: a small piece of the game realized at final quality, cutting through every discipline. It answers "can we actually make this?", sets the quality bar for the whole team, and — for funding or recruiting — shows rather than tells.
02
Rationale
A prototype proves the game is fun ("should we make this?", PROTO-0001); a vertical slice proves the team can produce it at the intended quality ("can we make it?") [S-proto-vertical-slice]. It de-risks production by forcing every discipline — art, code, audio, design, UX — through one representative piece at shipping fidelity, surfacing the real cost and the real bottlenecks before they're multiplied across the whole game. It also aligns the team on a concrete quality target ("this good, everywhere") far better than a document can, and it's the most persuasive artifact for funding, publishers, and recruits because it is the game in miniature. Choosing a tiny, representative slice is the craft — the temptation to show everything defeats the purpose.
03
Applies when
The transition from pre-production to full production, and any point you need to prove feasibility or the quality bar (pitching, funding, team alignment).
04
Does not apply / Exceptions
Very small or experimental projects may go straight from prototype to building. A vertical slice is expensive (it's real production work), so it's overkill when feasibility isn't in doubt. And a slice can become a trap if the team over-polishes it forever instead of using it to validate and move on — or if it's mistaken for a prototype and used to find the fun (that's PROTO-0001's job, done cheaper).
05
Implementation
Pick the smallest slice that is representative of the whole game, and build it to final quality across all disciplines. Use it to measure real production cost and extrapolate the full schedule (feeding PROD-0004). Treat it as a quality benchmark and a de-risking exercise, not a demo to endlessly polish. Keep the prototype (fun) and vertical slice (feasibility) distinct — they answer different questions.
06
Disagreement
Slice-first (prove feasibility and bar before scaling) vs. lighter-weight approaches (prototype then build, common for tiny teams who can't afford a full slice). The value of a slice scales with the project's size and risk; for a solo micro-game it may be unnecessary ceremony.
07
Notes
The production complement to PROTO-0001: prototype = "should we?", slice = "can we?". Feeds scheduling (PROD-0004) and the scope commitment (PROD-0001). Confidence 4.
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Connected principles
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