# 04 · Prove the mechanics in the sandbox

**Chapter** 04
**Blocked by** 03
**Spec and story IDs** [fill in for this release]

## What to build

Give the game a runnable sandbox with repeatable scenarios for the release scope.

## Acceptance checks

- [ ] Open the sandbox directly and reset each required scenario to a known state.
- [ ] Exercise mechanics and assets, including expected failure and recovery.
- [ ] Record results for the required checks before closing the chapter.

## Evidence and handoff

Expected evidence: Sandbox entry, scenario results, and evidence by build and target.

Record the actual result and its link, any failed or unverified checks, and the next unblocked ticket.