Claude-Code-Game-Studios/.claude/skills/balance-check/SKILL.md

---
name: balance-check
description: "Find balance outliers, broken progressions, degenerate strategies, economy imbalances in formulas and data. 'Check game balance'."
argument-hint: "[system-name|path-to-data-file]"
user-invocable: true
allowed-tools: Read, Glob, Grep, Write, AskUserQuestion
model: sonnet
---

!`source "${CLAUDE_PROJECT_DIR:-.}/.claude/hooks/yaml-helper.sh" 2>/dev/null && resolve_config --keys automation`



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).

## Insufficient input — check this before producing any report

**If the inputs this skill needs do not exist, the answer is "could not run" —
not a filled-in report.** Check first, and stop if the check fails.

1. List the inputs this skill reads (data files, prior reports, profiler output,
   test results, registries, source code).
2. For each, record `FOUND` or `ABSENT` — not "assumed present".
3. If any input required for a section is ABSENT, that section is
   **`NOT ASSESSED — NO DATA`**. Do not estimate it, do not infer it from an
   adjacent artifact, and do not leave a mandated cell to be filled by whoever
   reads the template next.
4. If **every** required input is ABSENT, stop and report
   **`NOT ASSESSED — NO DATA`** as the whole verdict, naming what was missing and
   which skill produces it.

**A verdict of `NOT ASSESSED` is a success.** It is the correct, useful answer to
"what does the data say?" when there is no data. The failure mode this prevents is
specific and has been observed in practice: report templates whose verdict
enum had no "could not run" state produced **false clean passes** — an asset audit
returning COMPLIANT on a project with no assets and no standards, and a
performance profile reporting ">99% headroom against a 16.67ms budget" with zero
profiler data and no budget ever set.

**Absence of evidence is never evidence of absence.** A scan that finds no
matches because there are no files to scan has not verified anything. Say which of
the two happened — a reader cannot tell from a green result.

---

## Phase 1: Identify Balance Domain

Determine the balance domain from `$ARGUMENTS[0]`:

- **Combat** → weapon/ability DPS, time-to-kill, damage type interactions
- **Economy** → resource faucets/sinks, acquisition rates, item pricing
- **Progression** → XP/power curves, dead zones, power spikes
- **Loot** → rarity distribution, pity timers, inventory pressure
- **File path given** → load that file directly and infer domain from content

If no argument, ask the user which system to check.

---

## Phase 2: Read Data Files

Read relevant files from `assets/data/` and `design/balance/` for the identified domain.
Note every file read — they will appear in the Data Sources section of the report.

---

## Phase 3: Read Design Document

**Registry first.** If `design/registry/entities.yaml` exists, read it before the
GDD. Its `constants` and `formulas` sections hold the cross-GDD named values and
output ranges — the balance targets — already distilled, each with a `source:`
GDD and any `revised:` date:
```
Grep pattern="^  - name:" path="design/registry/entities.yaml" output_mode="content" -A 6
```
Take the intended values from the registry for any constant or formula it lists
(the `constants:` and `formulas:` blocks); these are the authoritative cross-doc
figures a GDD must not contradict. **If `design/registry/entities.yaml` does not
exist or has no entries** (it ships as an empty stub until `/design-system`
populates it), skip this and use the GDD alone.

Then read the GDD for the system from `design/gdd/` to understand intended design
targets, tuning knobs, and expected value ranges — for anything the registry did
not already supply. This is the baseline for "correct" behaviour.

---

## Phase 4: Perform Analysis

Run domain-specific checks:

**Combat balance:**
- Calculate DPS for all weapons/abilities at each power tier
- Check time-to-kill at each tier
- Identify any options that dominate all others (strictly better)
- Check if defensive options can create unkillable states
- Verify damage type/resistance interactions are balanced

**Economy balance:**
- Map all resource faucets and sinks with flow rates
- Project resource accumulation over time
- Check for infinite resource loops
- Verify gold sinks scale with gold generation
- Check if any items are never worth purchasing

**Progression balance:**
- Plot the XP curve and power curve
- Check for dead zones (no meaningful progression for too long)
- Check for power spikes (sudden jumps in capability)
- Verify content gates align with expected player power
- Check if skip/grind strategies break intended pacing

**Loot balance:**
- Calculate expected time to acquire each rarity tier
- Check pity timer math
- Verify no loot is strictly useless at any stage
- Check inventory pressure vs acquisition rate

---

## Phase 5: Output the Analysis

```
## Balance Check: [System Name]

### Data Sources Analyzed
- [List of files read]

### Health Summary: [NOT ASSESSED / HEALTHY / CONCERNS / CRITICAL ISSUES]

### Outliers Detected
| Item/Value | Expected Range | Actual | Issue |
|-----------|---------------|--------|-------|

### Degenerate Strategies Found
- [Strategy description and why it is problematic]

### Progression Analysis
[Graph description or table showing progression curve health]

### Recommendations
| Priority | Issue | Suggested Fix | Impact |
|----------|-------|--------------|--------|

### Values That Need Attention
[Specific values with suggested adjustments and rationale]
```

---

## Phase 6: Fix & Verify Cycle

After presenting the report, use `AskUserQuestion`:
- Prompt: "Balance check complete. What would you like to do next?"
- Options:
  - `[A] Fix highest-priority issue now — walk me through it`
  - `[B] Save report to design/balance/balance-check-[system]-[date].md`
  - `[C] Stop here — I'll review the findings manually`

If [A]:
- Ask which issue to address first (refer to the Recommendations table by priority row)
- Guide the user to update the relevant data file in `assets/data/` or formula in `design/balance/`
- After each fix, offer to re-run the relevant balance checks to verify no new outliers were introduced
- If the fix changes a tuning knob defined in a GDD or referenced by an ADR, remind the user:
  > "This value is defined in a design document. Run `/propagate-design-change [path]` on the affected GDD to find downstream impacts before committing."

If [B]:
- Write the report to `design/balance/balance-check-[system]-[date].md` (create the directory if needed). Use the current date for [date] in YYYY-MM-DD format.
- Confirm the file was written, then end with: "Re-run `/balance-check` after fixes to verify."

If [C]:
- Summarize open issues and end with: "Re-run `/balance-check` after fixes to verify."