| name | quick-design |
| description | Lightweight design spec for small changes — tuning adjustments, minor mechanics, balance tweaks. Skips full GDD authoring when a system GDD already exists or the change is too small to warrant one. Produces a Quick Design Spec that embeds directly into story files. |
| argument-hint | [brief description of the change] |
| user-invocable | true |
| allowed-tools | Read, Glob, Grep, Write, Edit, AskUserQuestion |
| model | sonnet |
Quick Design
This is the lightweight design path for changes that don't need a full GDD.
Full GDD authoring via /design-system is the heavyweight path. Use this skill
for work under approximately 4 hours of implementation — tuning adjustments,
minor behavioral tweaks, small additions to existing systems, or standalone
features too small to warrant a full document.
Output: design/quick-specs/[name]-[date].md
When to run: Anytime a change is too small for /design-system but too
meaningful to implement without a written rationale.
1. Classify the Change
First, read the argument and determine which category this change falls into:
- Tuning — changing numbers or balance values in an existing system with no
behavioral change (most minimal path). Example: "increase jump height from 5
to 6 units", "reduce enemy patrol speed by 10%".
- Tweak — a small behavioral change to an existing system that introduces no
new states, branches, or systems. Example: "make dash invincible on frame 1",
"allow combo to cancel into roll".
- Addition — adding a small mechanic to an existing system that may introduce
1-2 new states or interactions. Example: "add a parry window to the block
mechanic", "add a charge variant to the basic attack".
- New Small System — a standalone feature small enough that it has no
existing GDD and is under approximately one week of implementation work.
Example: "achievement popup system", "simple day/night visual cycle".
If the change does NOT fit these categories — it introduces a new system with
significant cross-system dependencies, requires more than one week of
implementation, or fundamentally alters an existing system's core rules — stop
and redirect to /design-system instead.
If there is no argument, ask the user to describe the change (plain text prompt), then classify it using the criteria above.
Present the inferred classification using AskUserQuestion:
- Prompt: "I've classified this as [inferred type] — [brief reason]. Is that correct?"
- Options:
[A] Yes — [inferred type] is correct[B] Tuning — changing numbers or balance values only[C] Tweak — small behavioral change to an existing system[D] Addition — adding a small mechanic to an existing system[E] New Small System — standalone feature, under one week of work[F] This is too large — redirect me to /design-system
If [F]: stop. Verdict: REDIRECTED — use /design-system for this change.
Otherwise: proceed with the selected type.
2. Context Scan
Before drafting anything, read the relevant context:
- Search
design/gdd/ for the GDD most relevant to this change. Read the
sections that this change would affect.
- Check whether
design/gdd/systems-index.md exists. If it does, read it to
understand where this system sits in the dependency graph and what tier it
belongs to. If it does not exist, note "No systems index found — skipping
dependency tier check." and continue.
- Check
design/quick-specs/ for any prior quick specs that touched this
system — avoid contradicting them.
- If this is a Tuning change, also check
assets/data/ for the data file that
holds the relevant values.
Report what was found: "Found GDD at [path]. Relevant section: [section name].
No conflicting quick specs found." (or note any conflicts found.)
3. Draft the Quick Design Spec
Use the appropriate spec format for the change category.
For Tuning changes
Produce a single table:
# Quick Design Spec: [Title]
**Type**: Tuning
**System**: [System name]
**GDD Reference**: `design/gdd/[filename].md` — Tuning Knobs section
**Date**: [today]
## Change
| Parameter | Old Value | New Value | Rationale |
|-----------|-----------|-----------|-----------|
| [param] | [old] | [new] | [why] |
## Tuning Knob Mapping
Maps to GDD Tuning Knob: [knob name and its documented range].
New value is [within / at the edge of / outside] the documented range.
[If outside: explain why the range should be extended.]
## Acceptance Criteria
- [ ] [Parameter] reads [new value] from `assets/data/[file]`
- [ ] Behavior difference is observable in [specific context]
- [ ] No regression in [related behavior]
For Tweak and Addition changes
# Quick Design Spec: [Title]
**Type**: [Tweak / Addition]
**System**: [System name]
**GDD Reference**: `design/gdd/[filename].md`
**Date**: [today]
## Change Summary
[1-2 sentences describing what changes and why.]
## Motivation
[Why is this change needed? What player experience problem does it solve?
Reference the relevant MDA aesthetic or player feedback if applicable.]
## Design Delta
Current GDD says (quoting `design/gdd/[filename].md`, [section]):
> [exact quote of the relevant rule or description]
This spec changes that to:
[New rule or description, written with the same precision as a GDD Detailed
Rules section. A programmer should be able to implement from this text alone.]
## New Rules / Values
[Full unambiguous statement of the replacement content. If this introduces
new states, list them. If it introduces new parameters, define their ranges.]
## Affected Systems
| System | Impact | Action Required |
|--------|--------|-----------------|
| [system] | [how it is affected] | [update GDD / update data file / no action] |
## Acceptance Criteria
- [ ] [Specific, testable criterion 1]
- [ ] [Specific, testable criterion 2]
- [ ] [Specific, testable criterion 3]
- [ ] No regression: [the original behavior this must not break]
## GDD Update Required?
[Yes / No]
[If yes: which file, which section, and what the update should say.]
For New Small System changes
Use a trimmed GDD structure. Include only the sections that are directly
necessary — skip Player Fantasy, full Formulas, and Edge Cases unless the
system specifically requires them.
# Quick Design Spec: [Title]
**Type**: New Small System
**Scope**: [1-2 sentence description of what this system does and doesn't do]
**Date**: [today]
**Estimated Implementation**: [hours]
## Overview
[One paragraph a new team member could understand. What does this system do,
when does it activate, and what does it produce?]
## Core Rules
[Unambiguous rules for the system. Use numbered lists for sequential behavior
and bullet lists for conditions. Be precise enough that a programmer can
implement without asking questions.]
## Tuning Knobs
| Knob | Default | Range | Category | Rationale |
|------|---------|-------|----------|-----------|
| [name] | [value] | [min–max] | [feel/curve/gate] | [why this default] |
All values must live in `assets/data/[appropriate-file].json`, not hardcoded.
## Acceptance Criteria
- [ ] [Functional criterion: does the right thing]
- [ ] [Functional criterion: handles the edge case]
- [ ] [Experiential criterion: feels right — what a playtest validates]
- [ ] [Regression criterion: does not break adjacent system]
## Systems Index
This system is not currently in `design/gdd/systems-index.md`.
[If it should be added: suggest which layer and priority tier.]
[If it is too small to track: state "This system is below systems-index
tracking threshold — quick spec is sufficient."]
4. Approval and Filing
Present the draft to the user in full. Then use AskUserQuestion:
- Prompt: "Here's the Quick Design Spec draft. How do you want to proceed?"
- Options:
[A] Approve — write it as shown[B] Revise — I'll describe what to change[C] This grew too large — redirect to /design-system instead
If [B]: collect the requested changes, revise the draft, and re-present this widget.
If [C]: stop. Verdict: REDIRECTED — use /design-system for this change.
If [A]: ask "May I write this Quick Design Spec to
design/quick-specs/[kebab-case-title]-[YYYY-MM-DD].md?"
Use today's date in the filename. The title should be a kebab-case description
of the change (e.g., jump-height-tuning-2026-03-10,
parry-window-addition-2026-03-10).
If yes, create the design/quick-specs/ directory if it does not exist, then
write the file.
If a GDD update is required (flagged in the spec), ask separately after
writing the quick spec:
"This spec modifies rules in [System Name]. May I update
design/gdd/[filename].md — specifically the [section name] section?"
Show the exact text that would be changed (old vs. new) before asking. Do not
make GDD edits without explicit approval.
5. Handoff
After writing the file, output:
Quick Design Spec written to: design/quick-specs/[filename].md
Type: [Tuning / Tweak / Addition / New Small System]
System: [system name]
GDD update: [Required — pending approval / Applied / Not required]
Next step: This spec is ready for `/story-readiness` validation before
implementation. Reference this spec in the story's GDD Reference field.
Pipeline Notes
Verdict: COMPLETE — quick design spec written and ready for implementation.
Quick Design Specs bypass /design-review and /review-all-gdds by
design. They are for small, low-risk, well-scoped changes where the cost of
the full review pipeline exceeds the risk of the change itself.
Redirect to the full pipeline if any of the following are true:
- The change adds a new system that belongs in the systems index
- The change significantly alters cross-system behavior or a system's
contracts with other systems
- The change introduces new player-facing mechanics that affect the
game's MDA aesthetic balance
- Implementation is likely to exceed one week of work
In those cases: "This change has grown beyond quick-spec scope. I recommend
using /design-system to author a full GDD for this."
Recommended Next Steps
- Run
/story-readiness [story-path] to validate the story before implementation begins — reference this spec in the story's GDD Reference field
- Run
/dev-story [story-path] to implement once the story passes readiness checks
- If the change is larger than expected, run
/design-system [system-name] to author a full GDD instead
