# 0016: Crossplay and Cross-Progression Default

Status: Accepted

Date: 2026-05-25

## Context

V5 spans online co-op, PvP, companion app surfaces, and long-running campaign
state. Players need account continuity without making single-player dependent on
online service uptime.

## Decision

Crossplay and cross-progression are default V5 product requirements. Profile,
cosmetics, Bureau XP, and Mind Palace state sync across linked platforms, while
offline campaign paths remain playable and reconcile when services return.

## Consequences

- Save and profile systems must define conflict resolution.
- Single-player deterministic paths cannot depend on network output.
- Sci-Fi spaceship PvP can expose platform opt-out where input parity matters.