vertical-slice

To validate a game loop before production, build a 3–5 minute polished vertical slice demonstrating the core fantasy without developer guidance. This measures real development velocity and yields a gated PROCEED, PIVOT, or KILL recommendation for production advancement.

A vertical slice in game development is a fully playable, production-quality segment demonstrating the core loop from start to resolution. You need one during pre-production to prove the full loop works within realistic time and pipeline constraints before committing to production.

Control scope when building a pre-production prototype by enforcing strict slice length targets and cutting scope before cutting quality. This avoids misleading playtest results and ensures the prototype accurately represents the production pipeline's capabilities.

Yes, you can re-run architecture validation after a game design pivot. The vertical slice process supports iterative re-runs to re-validate changed design decisions, loading the updated GDDs, architecture, and UX specs to ensure the new direction is feasible.

Measure development velocity before game production by tracking actual day-by-day progress while building the vertical slice. This provides an accurate production rate estimate rather than relying on assumptions, directly informing the final production gating decision.

A key limitation is that a vertical slice only validates the specific game loop tested; it requires resolving review mode and loading complete design context. If scope is not disciplined, the slice may yield misleading playtest results that compromise the gating verdict.