Holistic cross-GDD consistency and game design review. Reads all system GDDs simultaneously and checks for contradictions between them, stale references, ownership conflicts, formula incompatibilities, and game design theory violations (dominant strategies, economic imbalance, cognitive overload, pillar drift). Run after all MVP GDDs are written, before architecture begins.
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This skill reads every system GDD simultaneously and performs two complementary reviews that cannot be done per-GDD in isolation:
This is distinct from /design-review, which reviews one GDD for internal
completeness. This skill reviews the relationships between all GDDs.
When to run:
/create-architecture begins (architecture built on inconsistent GDDs
inherits those inconsistencies)Argument modes:
Focus: $ARGUMENTS[0] (blank = full)
full: Both consistency and design theory passesconsistency: Cross-GDD consistency checks only (faster)design-theory: Game design holism checks onlysince-last-review: Only GDDs modified since the last review report (git-based)Before reading any full document, use Grep to extract ## Summary sections
from all GDD files:
Grep pattern="## Summary" glob="design/gdd/*.md" output_mode="content" -A 5Display a manifest to the user:
Found [N] GDDs. Summaries:
• combat.md — [summary text]
• inventory.md — [summary text]
...For since-last-review mode: run git log --name-only to identify GDDs
modified since the last review report file was written. Show the user which
GDDs are in scope based on summaries before doing any full reads. Only
proceed to L1 for those GDDs plus any GDDs listed in their "Key deps".
Before full-reading any GDD, check for the entity registry:
Read path="design/registry/entities.yaml"If the registry exists and has entries, use it as a pre-built conflict baseline: known entities, items, formulas, and constants with their authoritative values and source GDDs. In Phase 2, grep GDDs for registered names first — this is faster than reading all GDDs in full before knowing what to look for.
If the registry is empty or absent: proceed without it. Note in the report:
"Entity registry is empty — consistency checks rely on full GDD reads only.
Run /consistency-check after this review to populate the registry."
Full-read the in-scope documents:
design/gdd/game-concept.md — game vision, core loop, MVP definitiondesign/gdd/game-pillars.md if it exists — design pillars and anti-pillarsdesign/gdd/systems-index.md — authoritative system list, layers, dependencies, statusdesign/gdd/ — read completely (skip
game-concept.md and systems-index.md — those are read above)Report: "Loaded [N] system GDDs covering [M] systems. Pillars: [list]. Anti-pillars: [list]."
If fewer than 2 system GDDs exist, stop:
"Cross-GDD review requires at least 2 system GDDs. Write more GDDs first, then re-run
/review-all-gdds."
Phase 2 (Consistency) and Phase 3 (Design Theory) are independent — they read the same GDD inputs but produce separate reports. Spawn both as parallel Task agents simultaneously rather than waiting for Phase 2 to complete before starting Phase 3. Collect both results before writing the combined report.
When spawning parallel Task agents for Phase 2 and Phase 3, always pass:
.claude/docs/technical-preferences.md and docs/engine-reference/[engine]/VERSION.mdDo not rely on the subagent to re-read these files — it has its own context window and cannot access Phase 1 results unless they are explicitly passed in the Task prompt.
Work through every pair and group of GDDs to find contradictions and gaps.
For every GDD's Dependencies section, check that every listed dependency is reciprocal:
⚠️ Dependency Asymmetry
[system-a].md lists: Depends On → [system-b].md
[system-b].md does NOT list [system-a].md as a dependent
→ One of these documents has a stale dependency sectionFor each game rule, mechanic, or constraint defined in any GDD, check whether any other GDD defines a contradicting rule for the same situation:
Categories to scan:
🔴 Rule Contradiction
[system-a].md: "Minimum [output] after reduction is [floor_value]"
[system-b].md: "[mechanic] bypasses [system-a]'s rules and can reduce [output] to 0"
→ These rules directly contradict. Which GDD is authoritative?For every cross-document reference (GDD-A mentions a mechanic, value, or system name from GDD-B), verify the referenced element still exists in GDD-B with the same name and behaviour:
⚠️ Stale Reference
inventory.md (written first): "Item weight uses the encumbrance formula
from movement.md"
movement.md (written later): Defines no encumbrance formula — uses a flat
carry limit instead
→ inventory.md references a formula that doesn't existTwo GDDs should not both claim to own the same data or tuning knob. Scan all Tuning Knobs sections across all GDDs and flag duplicates:
⚠️ Ownership Conflict
[system-a].md Tuning Knobs: "[multiplier_name] — controls [output] scaling"
[system-b].md Tuning Knobs: "[multiplier_name] — scales [output] with [factor]"
→ Two GDDs define multipliers on the same output. Which owns the final value?
This will produce either a double-application bug or a design conflict.For GDDs whose formulas are connected (output of one feeds input of another), check that the output range of the upstream formula is within the expected input range of the downstream formula:
Flag incompatibilities as CONCERNS (design judgment needed, not necessarily wrong):
⚠️ Formula Range Mismatch
[system-a].md: Max [output] = [value_a] (at max [condition])
[system-b].md: Base [input] = [value_b], max [input] = [value_c]
→ Late-[stage] [scenario] can resolve in a single [event].
Is this intentional? If not, either [system-a]'s ceiling or [system-b]'s ceiling needs adjustment.Scan Acceptance Criteria sections across all GDDs for contradictions:
Review all GDDs together through the lens of game design theory and player psychology. These are issues that individual GDD reviews cannot catch because they require seeing all systems at once.
A game should have one dominant progression loop that players feel is "the point" of the game, with supporting loops that feed into it. When multiple systems compete equally as the primary progression driver, players don't know what the game is about.
Scan all GDDs for systems that:
⚠️ Competing Progression Loops
combat.md: Awards XP, unlocks abilities, is described as "the core loop"
crafting.md: Awards XP, unlocks recipes, is described as "the primary activity"
exploration.md: Awards XP, unlocks map areas, described as "the main driver"
→ Three systems all claim to be the primary progression loop and all award
the same primary currency. Players will optimise one and ignore the others.
Consider: one primary loop with the others as support systems.Count how many systems require active player attention simultaneously during a typical session. Each actively-managed system costs attention:
More than 3-4 simultaneously active systems creates cognitive overload for most players. Present the count and flag if it exceeds 4 concurrent active systems:
⚠️ Cognitive Load Risk
Simultaneously active systems during [core loop moment]:
1. [system-a].md — [decision type] (active)
2. [system-b].md — [resource management] (active)
3. [system-c].md — [tracking] (active)
4. [system-d].md — [item/action use] (active)
5. [system-e].md — [cooldown/timer management] (active)
6. [system-f].md — [coordination decisions] (active)
→ 6 simultaneously active systems during the core loop.
Research suggests 3-4 is the comfortable limit for most players.
Consider: which of these can be made passive or simplified?A dominant strategy makes other strategies irrelevant — players discover it, use it exclusively, and find the rest of the game boring. Look for:
⚠️ Potential Dominant Strategy
combat.md: Ranged attacks deal 80% of melee damage with no risk
combat.md: Melee attacks deal 100% damage but require close range
→ Unless melee has a significant compensating advantage (AOE, stagger,
resource regeneration), ranged is dominant — higher safety, only 20% less
damage. Consider what melee offers that ranged cannot.Identify all resources across all GDDs (gold, XP, crafting materials, stamina, health, mana, etc.). For each resource, map its sources (how players gain it) and sinks (how players spend it).
Flag dangerous economic conditions:
| Condition | Sign | Risk |
|---|---|---|
| Infinite source, no sink | Resource accumulates indefinitely | Late game becomes trivially easy |
| Sink, no source | Resource drains to zero | System becomes unavailable |
| Source >> Sink | Surplus accumulates | Resource becomes meaningless |
| Sink >> Source | Constant scarcity | Frustration and gatekeeping |
| Positive feedback loop | More resource → easier to earn more | Runaway leader, snowball |
| No catch-up | Falling behind accelerates deficit | Unrecoverable states |
🔴 Economic Imbalance: Unbounded Positive Feedback
gold economy:
Sources: monster drops (scales with player power), merchant selling (unlimited)
Sinks: equipment purchase (one-time), ability upgrades (finite count)
→ After equipment and abilities are purchased, gold has no sink.
Infinite surplus. Gold becomes meaningless mid-game.
Add ongoing gold sinks (upkeep, consumables, cosmetics, gambling).When multiple systems scale with player progression, they must scale in compatible directions and at compatible rates. Mismatched scaling curves create unintended difficulty spikes or trivialisations.
For each system that scales over time, extract:
Compare all scaling curves. Flag mismatches:
⚠️ Difficulty Curve Mismatch
combat.md: Enemy health scales exponentially with area (×2 per area)
progression.md: Player damage scales linearly with level (+10% per level)
→ By area 5, enemies have 32× base health; player deals ~1.5× base damage.
The gap widens indefinitely. Late areas will become inaccessibly difficult
unless the curves are reconciled.Every system should clearly serve at least one design pillar. A system that serves no pillar is "scope creep by design" — it's in the game but not in service of what the game is trying to be.
For each GDD system, check its Player Fantasy section against the design pillars. Flag any system whose stated fantasy doesn't map to any pillar:
⚠️ Pillar Drift
fishing-system.md: Player Fantasy — "peaceful, meditative activity"
Pillars: "Brutal Combat", "Tense Survival", "Emergent Stories"
→ The fishing system serves none of the three pillars. Either add a pillar
that covers it, redesign it to serve an existing pillar, or cut it.Also check anti-pillars — flag any system that does what an anti-pillar explicitly says the game will NOT do:
🔴 Anti-Pillar Violation
Anti-Pillar: "We will NOT have linear story progression — player defines their path"
main-quest.md: Defines a 12-chapter linear story with mandatory sequence
→ This system directly violates the defined anti-pillar.The player fantasies across all systems should be compatible — they should reinforce a consistent identity for what the player IS in this game. Conflicting player fantasies create identity confusion.
⚠️ Player Fantasy Conflict
combat.md: "You are a ruthless, precise warrior — every kill is earned"
dialogue.md: "You are a charismatic diplomat — violence is always avoidable"
exploration.md: "You are a reckless adventurer — diving in without a plan"
→ Three systems present incompatible identities. Players will feel the game
doesn't know what it wants them to be. Consider: do these fantasies serve
the same core identity from different angles, or do they genuinely conflict?Walk through the game from the player's perspective to find problems that only appear at the interaction boundary between multiple systems — things static analysis of individual GDDs cannot surface.
Scan all GDDs and identify the 3–5 most important player-facing moments where multiple systems activate simultaneously. Look specifically for:
List each identified scenario with a one-line description before proceeding.
For each scenario, step through the sequence explicitly:
Example walkthrough:
Scenario: Player kills elite enemy at level-up threshold during active quest
Trigger: Player lands killing blow on elite enemy
→ combat.md: awards kill XP (100 pts)
→ progression.md: XP total crosses level threshold → triggers level-up
Output: new level, stat increases, ability unlock popup
→ quest.md: kill-count criterion met → triggers quest completion event
Output: quest reward XP (500 pts), completion fanfare
→ progression.md (again): quest XP added → triggers SECOND level-up in same frame
⚠️ Data flow issue: quest.md awards XP without checking if a level-up
is already in progress. progression.md has no guard against concurrent
level-up events. Undefined behavior: does the player level up once or twice?
Does the ability popup fire twice? Does the second level use the updated or
pre-update stat baseline?For each problem found during the walkthrough, categorize severity:
Add all findings to the output report under "Cross-System Scenario Issues". Each finding must cite: the scenario name, the specific systems involved, the step where the issue occurs, and the nature of the failure mode.
## Cross-GDD Review Report
Date: [date]
GDDs Reviewed: [N]
Systems Covered: [list]
---
### Consistency Issues
#### Blocking (must resolve before architecture begins)
🔴 [Issue title]
[What GDDs are involved, what the contradiction is, what needs to change]
#### Warnings (should resolve, but won't block)
⚠️ [Issue title]
[What GDDs are involved, what the concern is]
---
### Game Design Issues
#### Blocking
🔴 [Issue title]
[What the problem is, which GDDs are involved, design recommendation]
#### Warnings
⚠️ [Issue title]
[What the concern is, which GDDs are affected, recommendation]
---
### Cross-System Scenario Issues
Scenarios walked: [N]
[List scenario names]
#### Blockers
🔴 [Scenario name] — [Systems involved]
[Step where failure occurs, nature of the failure mode, what must be resolved]
#### Warnings
⚠️ [Scenario name] — [Systems involved]
[What the unintended outcome is, recommendation]
#### Info
ℹ️ [Scenario name] — [Systems involved]
[Minor ordering ambiguity or note]
---
### GDDs Flagged for Revision
| GDD | Reason | Type | Priority |
|-----|--------|------|----------|
| [system-a].md | Rule contradiction with [system-b].md | Consistency | Blocking |
| [system-c].md | Stale reference to nonexistent mechanic | Consistency | Blocking |
| [system-d].md | No pillar alignment | Design Theory | Warning |
---
### Verdict: [PASS / CONCERNS / FAIL]
PASS: No blocking issues. Warnings present but don't prevent architecture.
CONCERNS: Warnings present that should be resolved but are not blocking.
FAIL: One or more blocking issues must be resolved before architecture begins.
### If FAIL — required actions before re-running:
[Specific list of what must change in which GDD]Use AskUserQuestion for write permission:
design/gdd/gdd-cross-review-[date].md?"[A] Yes — write the report / [B] No — skipIf any GDDs are flagged for revision, use a second AskUserQuestion:
[A] Yes — update systems index / [B] No — leave as-isAfter writing the report (and updating systems index if approved), silently
append to production/session-state/active.md:
## Session Extract — /review-all-gdds [date]
- Verdict: [PASS / CONCERNS / FAIL]
- GDDs reviewed: [N]
- Flagged for revision: [comma-separated list, or "None"]
- Blocking issues: [N — brief one-line descriptions, or "None"]
- Recommended next: [the Phase 7 handoff action, condensed to one line]
- Report: design/gdd/gdd-cross-review-[date].md ← only if user approved the write
- Report: (not written — user declined at [date]) ← only if user declined the writeUse the appropriate line based on the user's response to the write-permission widget in Phase 6.
If active.md does not exist, create it with this block as the initial content.
Confirm in conversation: "Session state updated."
After all file writes are complete, use AskUserQuestion for a closing widget.
Before building options, check project state:
Build the option list dynamically — only include options that apply:
Option pool:
[_] Apply quick fix: [W-XX description] in [gdd-name].md — [effort estimate] (one option per simple-edit warning; only for Warning-level, not Blocking)[_] Run /design-review [flagged-gdd-path] — address flagged warnings (one per flagged GDD, if any)[_] Run /design-system [next-system] — next in design order (always include, name the actual system)[_] Run /create-architecture — begin architecture (verdict is PASS/CONCERNS) (include if verdict is not FAIL)[_] Run /gate-check — validate Systems Design phase gate (include if verdict is PASS)[_] Stop hereAssign letters A, B, C… only to included options. Mark the most pipeline-advancing option as (recommended).
Never end the skill with plain text. Always close with this widget.
If any spawned agent returns BLOCKED, errors, or fails to complete:
984023d
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