balance-design git:20260913.716a31eA

Immutable. This exact content never changes and is served at /api/v1/blob/1ed644dce8ef0cf0.

---
name: balance-design
description: Use when comparing options, matchups, roles, economies or catch-up systems and the project needs explicit balance goals, metrics, tradeoffs and versioned evidence instead of universal fairness rules.
---

# Balance design

Choose the project goal before changing numbers.

## Contract

Publish:
- stable `balance_policy_id` and revision
- population/mode/build scope
- primary metric definition and denominator
- secondary guardrails
- compared option or matchup IDs
- authored tradeoffs and allowed asymmetry
- evidence window and confidence/coverage limits

Balance may target viability, role separation, pacing, accessibility, competitive parity, progression, spectacle, or another stated project goal. No one target is universal.

## Ownership

This skill owns balance policy and evidence interpretation. It consumes combat/economy/race/system values from their true owners; it does not silently rewrite hitstop, input timing, camera, collision, grants or other system contracts.

## Rules

1. Compare like-for-like contexts; a global average without mode/rank/loadout denominator is not evidence.
2. Distinguish intentional asymmetry from accidental dominance.
3. Counter strength, comeback systems and catch-up behavior are project policies, not universal moral rules.
4. Every tuning change records before/after policy revision, changed values and expected metric movement.
5. If a change alters another owner's contract, route the change there and rerun its acceptance tests.

## Acceptance

A reviewer can identify the balance objective, denominator, compared IDs, intentional tradeoffs, changed revision and evidence required to keep or revert the change. A different design philosophy can use the same contract without inheriting hidden genre assumptions.