version: "1.0.1" name: vertical-slice-planning description: Define a vertical slice that proves gameplay, quality bars, and production viability without over-building the full game. origin: everything-game-dev-code category: workflow

Vertical Slice Planning

Purpose

Define a vertical slice that proves gameplay, quality bars, and production viability without over-building the full game.

Use When

• moving from concept into pre-production
• you need investor, publisher, or internal proof of feasibility
• the team needs a shared quality bar

Inputs

• game pillars
• candidate feature set
• team capacity
• target platforms and risks

Process

1. choose the smallest scope that still demonstrates the intended experience
2. define what must be real versus what can stay stubbed or faked
3. set success criteria across gameplay, UX, art, audio, and performance
4. identify risks the slice must retire
5. turn the slice into milestone-sized deliverables

Outputs

• vertical slice definition
• quality bar checklist
• risk retirement goals
• milestone scope for the slice

Quality Bar

• the slice has a single stated proof goal: what it must demonstrate and to whom
• every included feature ties to the proof goal; everything else is explicitly cut
• acceptance criteria are demonstrable in a single playthrough session
• the plan states what is faked (placeholder art, scripted sequences) and what must be real

Common Failure Modes

• slices that try to prove everything and become miniature full productions
• including features because they exist, not because the proof goal needs them
• undeclared fakery — stakeholders judge faked systems as real, or real systems as faked
• no explicit decision about what happens after the slice (promote, rebuild, or discard)

Related Agents

• planner
• producer
• gdd-designer
• technical-design-lead

Related Commands

• vertical-slice
• milestone-plan
• plan

Notes

• Keep this skill aligned with the relevant rules layer and current project documentation.
• If engine-specific constraints materially change the workflow, hand off to the matching engine skill or engine-specific reviewer.