# Vertical Slice

Pre-production validation, end-to-end build to confirm the full loop is achievable...

- Repository: https://github.com/Donchitos/Claude-Code-Game-Studios (32144 stars)
- Category: Design
- License: MIT
- Last updated: 2026-10-19
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add Donchitos/Claude-Code-Game-Studios --skill vertical-slice -g -a claude-code -y`
Codex: `npx skills add Donchitos/Claude-Code-Game-Studios --skill vertical-slice -g -a codex -y`
Cursor: `npx skills add Donchitos/Claude-Code-Game-Studios --skill vertical-slice -g -a cursor -y`
Gemini CLI: `npx skills add Donchitos/Claude-Code-Game-Studios --skill vertical-slice -g -a gemini-cli -y`

## Description

Pre-production validation, end-to-end build to confirm the full loop is achievable before committing to Production. After GDDs, architecture, UX specs.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

!`bash "${CLAUDE_SKILL_DIR}/../../hooks/yaml-helper.sh" resolve_config --keys review_mode,automation,workflow`

Resolved above, use as-is; `--review` overrides `review_mode` for this run. No
block → defaults in `.claude/docs/config-resolution.md`.

# Vertical Slice



## Purpose

The **vertical slice** answers a different question from the concept prototype:
*"Can we build this full game loop at production quality, on schedule?"*

**Default use**, run late in Pre-Production, after GDDs, architecture, and UX
specs are complete. It is a near-production-quality build demonstrating one complete
[start → challenge → resolution] cycle.

**Post-pivot?** If a PIVOT verdict from an earlier vertical slice sent you back to
revise GDDs and architecture, run this again after revisions to re-validate. It can
be run as many times as needed until a PROCEED or KILL verdict is reached.

It validates:

1. The pipeline (can the team actually produce this quality of content?)
2. Execution feasibility (are the architecture decisions correct for this game?)
3. Fun survival (does the fun from the concept prototype survive full design?)
4. **Velocity** (how long did this take? That's your real production rate estimate.)

**Earlier in the project?** If you haven't written GDDs yet and want to validate
whether the core idea is worth designing, run `/prototype` (concept prototype) instead.

---

## Phase 1: Resolve Review Mode and Load Context


See `.claude/docs/director-gates.md` for the full check pattern. Individual gate definitions live in `.claude/docs/director-gates/[gate-id].md`, the spawned agent reads its own gate file; do not read it in the parent session.


Every `AskUserQuestion` call follows `.claude/docs/automation-modes.md`
(collaborative asks always · guided major-only · autonomous logs and proceeds;
`automation_always_ask` categories always prompt).

The rest: https://github.com/Donchitos/Claude-Code-Game-Studios/blob/HEAD/.claude/skills/vertical-slice/SKILL.md