# 0003: Mind Palace as a Cross-Cell Layer

Status: Accepted

Date: 2026-05-25

## Context

The Mind Palace provides deduction, evidence chains, and accusation logic that
connect cases and clues across all V5 cells. Treating it as a sixth cell would
split ownership and dilute the five-cell product structure.

## Decision

Mind Palace is a cross-cell layer, not a sixth ruleset cell. It owns evidence
graphs, deduction state, accusation gates, and cross-era linkage while consuming
clues from Urban, Period, Frontier, Hunter, and Sci-Fi content.

## Consequences

- Mind Palace data persists across all per-cell save slots.
- Cell plugins can emit evidence without taking ownership of the global
  deduction graph.
- Product and test reporting keep the launch scope at five cells plus one
  cross-cell layer.