---
id: CB-WP-0022
kind: product
title: "The design instrument: findings about the game, with their reproductions"
status: done
state_hub_workstream_id: "fda16340-0049-4acf-884b-a5cfdbde47c0"
---

# Purpose

```
structural tier  L   (named a high-leverage pass by the maintainer, and it
                      amends INTENT — clay-borg gains a stated aspect)
chaos            d8 = 6  → no override
declared tier    L
```

Declaration 5 of chaos window 2. Tier L: separate survey, **adversarial
review**, ADR, then spec, then code.

## The insight, in the maintainer's words

> *"We should consider ourselves testing the game and document
> inconsistencies to report them back to the ground-game repo, so that the
> game designer can improve the rules accordingly… We should have the
> rigorous game simulation engine and a meta scope to capture notes about
> game design flaws, questions, results and protocols about trial games…
> This will provide clay-borg an additional aspect as a valuable game
> design tool."*

**This is already happening and has no home.** In five passes the engine
has produced, as a by-product of being rigorous:

| finding | how it surfaced |
|---|---|
| ten underdetermined rules points (U1–U10) | formalizing the dataset into testable rules |
| SOLVE offered on a face-down Problem, always inert | a human dragging it three rounds running |
| GR-A13 "wasted SOLVE" on a claimed Problem | a scenario that had to pick a default |
| ~~GR-E01 unreachable below 5 seats~~ | arithmetic over the deal count — **withdrawn 2026-08-05, it was wrong (C1)** |
| ~~six provisional scenario defaults~~ | **five, and double-counted with GR-E01 (C3)** — they are reproductions, not a finding |
| GR-E03 / GR-E04 never played to the end | nobody noticed for nineteen passes |

Every one was found by *building the simulator*, not by playing. That is
the thing worth naming: **a simulator rigorous enough to refuse ambiguity
is a design instrument, because it cannot proceed past a rule that does
not decide.**

And every one of them has been carried in prose, in six different places,
and one sat unread in an inbox for four days.

## The load-bearing rule this must have

The project's standing failure is *unexecuted verification*. A design
register that collects opinions would reproduce it in a new medium.

> **A design finding is not admissible without its reproduction.**

Concretely: a scenario that fails, an arithmetic check that prints the
contradiction, a recorded game the reader can replay, or a named test.
*"This feels unbalanced"* is a note, not a finding. **The SOLVE inertness
is admissible because a recorded session shows three no-ops.**

> **The example that stood here was GR-E01, and the review killed it
> (C1).** *"4/6/9 against 5/7/9 is a computation anyone can rerun"* had
> already been rerun: `2da19a4` measured **6/9/12**, and the scenario was
> renamed `-unreachable-` → `-reachable-`. The conclusion inverted — and
> it was one of the two findings that **passed** this rule. So existence
> is not what was missing. See [ADR-0012](../decisions/ADR-0012-the-design-instrument.md)
> D3: the rule gains **shape**, and **a reproduction must be able to
> fail.** Ours went green and stayed admissible.

This is what would make clay-borg a design tool rather than a suggestion
box, and it is the one part of this proposal that must not be traded away
for convenience.

## The judgment I want reviewed, not assumed

The maintainer asked whether this should extend to *"a meta about the
clay-borg engine evolution itself."*

**My answer is no, and it should be argued rather than accepted.** That
register already exists and is load-bearing: `evidence/CB-EV-*`,
`decisions/ADR-*`, `gates.toml` and the workplans capture nineteen passes
with dates, costs and falsifiers. A second register for the same subject
would be ceremony. The asymmetry is the point: engine evolution has a home
and game design does not.

> **Settled by [ADR-0012](../decisions/ADR-0012-the-design-instrument.md)
> D7: no register — but the argument above did not survive.** C5 found the
> "third thing" the maintainer meant is visible in
> `specs/InnerLoopReference.md` and `history/`'s retrospectives, **neither
> of which this inventory names.** Conclusion narrowed, not settled: if
> InnerLoopReference keeps absorbing material that is neither a decision
> nor a finding, revisit.

## Task: survey how this is done elsewhere, and what we already have

```task
id: CB-WP-0022-T01
status: done
priority: high
state_hub_task_id: "6b8663b8-4143-4361-ad9e-7df0c4f4a19d"
```

`research/CB-RES-0007-*.md`.

**Do not survey issue trackers.** The question is narrower and more
interesting: how do rigorous rule systems record *the ambiguity they
found*? Candidates worth a benchmark-to-beat:

- **Errata and rulings practice** in published games (Magic's
  comprehensive-rules + rulings split, Netrunner's NAPD card rulings) —
  what makes a ruling *findable* years later.
- **Formal-methods counterexample traces** — a model checker's output is
  precisely a reproduction attached to a claim, which is the shape wanted
  here.
- **Conformance-suite provisional behaviour** — how W3C/WHATWG mark
  "implementation-defined" and how a spec later absorbs it.
- **What this repo already has**: `provisional: true` scenarios,
  `§Underdetermined`, `gates.toml`'s `caught`/`retire_if` shape, and the
  hub message that went unread. **The register must reuse the provisional
  machinery rather than compete with it.**

Name, per dimension, the property to beat — findability, reproducibility,
and whether a ruling can *close* a finding mechanically.

**Done 2026-08-03.**
[CB-RES-0007](../research/CB-RES-0007-design-instrument.md), with a
runnable baseline (`tools/design-baseline.py`).

**Its numbers were withdrawn by T02 and must not be quoted from here.**
The survey reported *6 findings, 2/6 = 33% reproduced, 11 files, 4 days*.
C2 showed the instrument counted itself and its reproduction check never
stat'd the file; C3 showed *"six provisional defaults"* is five and GR-E01
was double-counted; T05's backfill contradicted *"six of the ten have
provisional scenarios"* — **one** does. What survives is direction: many
files, no index, 0 of 10 ruled. The first honest figures are T05's.

**Magic corrected an assumption this pass was about to build on.** Rulings
are *"reminder information with no actual weight or rules meaning"*; the
authoritative fix folds into the **Oracle** card text. **A finding closes
when the source changes, not when an annotation is added** — the register
is a queue that empties. Model checkers supplied the reproduction rule
independently, and W3C's *implementation-defined* mark is machinery we
already have and must reuse rather than duplicate.

## Task: adversarial review

```task
id: CB-WP-0022-T02
status: done
priority: high
state_hub_task_id: "d2597895-fe2e-4f1e-a3db-a5fb8833434c"
```

Tier L requires it. Give the reviewer the survey **and** the §judgment
above, and require an attempt at:

- **that the engine-evolution register is redundant** — the strongest
  counter is that ADRs record *decisions* and evidence records *findings*,
  but nothing records *what we learned about building engines*, which is a
  third thing;
- **that "carries its reproduction" is affordable** — if half the real
  findings cannot be reproduced cheaply, the rule will be quietly dropped
  and the register becomes a suggestion box anyway. *(Hardened before the review ran: two findings had already reached
  ground-game on wrong premises, so the reviewer was told to press whether
  the rule is **sufficient**, not whether it is affordable.)*
- **that a register is needed at all**, rather than one more section in
  `GroundRules.md §Underdetermined`, which already exists and already
  works.

Record the trail in `history/`, unpolished.

**Done 2026-08-05.** Trail:
[challenge](../history/260805-design-instrument-challenge.md),
[response](../history/260805-design-instrument-response.md).

**Run by a separate agent** — the first in this repo that was. CB-RES-0006's
review opened by conceding it could not be, and called its own findings
*"a lower bound on what a genuinely separate reviewer would find."* That
was measurable, and this is the measurement: the separate reviewer ran
`git log` against the survey's central example and found our own commit
had falsified it four days earlier, while the author — who wrote that
commit — quoted the dead number twice.

**Seven challenges: four conceded, two conceded in part, one answered.**
**C1 changed the design** — the rule's showcase finding was false and had
*passed* the rule, so existence is not what was missing — and **caught a
defect in flight**, T06's payload still naming the dead number. C2
withdrew the baseline's precision, C3 its arithmetic, C4 flipped T03's
burden toward extending `§Underdetermined`, C5 corrected the redundancy
inventory. Survived: affordability, and reuse of the provisional
machinery. Full account:
[CB-EV-0021](../evidence/CB-EV-0021-the-design-instrument.md) §1–§3.

## Task: decide

```task
id: CB-WP-0022-T03
status: done
priority: high
state_hub_task_id: "a2e85810-e949-4ea0-81fc-36b912af326c"
```

`decisions/ADR-0012-*.md`. At minimum:

- whether clay-borg's **INTENT gains a stated aspect** as a design
  instrument, and in what words — this is the change with the longest
  half-life in the pass;
- the finding **taxonomy**, and it should be grounded in the six findings
  above rather than invented: *underdetermined* (rules do not say),
  *inconsistent* (rules disagree with each other or the data), *inert* (a
  rule that cannot fire), *degenerate* (fires, but collapses play),
  *unplayed* (implemented, never played);
- the **lifecycle** and who owns each state: raised → reported → ruled →
  applied, or withdrawn;
- whether a finding without a reproduction is **rejected** or **admitted
  as a note** — and if admitted, how it is prevented from aging into an
  apparent finding.

**Done 2026-08-05.**
[ADR-0012](../decisions/ADR-0012-the-design-instrument.md), nine
decisions. The two not on this list are the two the review forced:

- **D2 — `§Underdetermined` *is* the register; nothing parallel is built.**
  Against the survey's own five benchmarks the incumbent already delivers
  four, including the Oracle property the survey went to Magic to find and
  we had written ourselves eight days earlier (`GroundRules.md:231-233`).
  What it lacks is reproductions. So this pass **extends** a section — no
  new file, no new schema.
- **D3 — admissibility is three clauses.** Exists, has the ruled shape
  (row-level table, never a sum), **and can fail.** GR-E01's artifact went
  green and the finding stayed admissible and stayed queued, because
  nothing said a passing artifact was a signal. **A green reproduction is
  an alarm.**

The rest, in one line each: **D1** INTENT gains property 4, *Instrument*,
applied with its falsifier. **D4** five kinds, each forced by an existing
finding. **D5** `applied` means the source changed; withdrawals are
reported, not deleted. **D6** notes admitted but never reportable, 30-day
expiry. **D7** no engine-evolution register, on an inventory C5 corrected.
**D8** `design-baseline.py` retired. **D9** the artifact stays here,
ground-game gets a generated file under its own workplan.

## Task: specify

```task
id: CB-WP-0022-T04
status: done
priority: high
state_hub_task_id: "60ddfeab-81b1-45e4-9ec9-91cc8ea7fb72"
```

`specs/GameDesign.md`, with metrics, because a spec without them is prose.

Candidate measures, to be argued not adopted:

- **findings with a runnable reproduction** — target 100%, and the
  denominator includes withdrawn ones;
- **time from raised to reported** — the U-items took four days to be
  *read*; that is the number this exists to fix;
- **findings closed by a ruling** vs **findings still open**, with age.

**ground-game has ruled on what a finding must carry** (GROUND-WP-0004
T02, 2026-08-04), and it is stricter than this pass proposed. Adopt it:

> Arithmetic findings ship a **runnable reproduction** *and* a
> **row-level deal table** — never only "sum of file" or "deal depth N";
> and ground-game's arithmetic rulings cite that reproduction by path.

The second half is theirs to keep. **So the reproduction rule gains a
shape requirement, not just an existence one** — a finding that ships a
passing test but describes the wrong quantity is still a bad finding,
which is exactly what happened twice.

Also specify the **trial protocol**: a trial game is a `--record`ed
session plus an observation log, so *"we played it and X happened"* is
replayable rather than remembered. It must cost almost nothing or it will
not be done.

**Done 2026-08-05.** [specs/GameDesign.md](../specs/GameDesign.md) v1.0 —
not a register (ADR-0012 D2 put that in `§Underdetermined`).

**§1.2 is written against evidence rather than principle**: a finding must
print the rows behind any number it claims. *"12" was arithmetically
defensible and still wrong about the game.* **§1.3's target is `0`
reproductions gone green while open** — what GR-E01 would have tripped
four days before a human caught it. **No baseline rate is quoted.**

**The trial protocol costs one flag**: `cb-play --record` plus a sibling
`.md` in the player's own words. An observation is a **note** until it has
a reproduction — *"I felt it was too easy but then we lost"* is the case
it is shaped around, and a schema at the moment of observation would lose
it.

## Task: build it, and backfill what is already known

```task
id: CB-WP-0022-T05
status: done
priority: high
state_hub_task_id: "469413ba-ed47-4840-a60e-ee7f95dc06ff"
```

The register, the tool, and then **the six findings above entered into
it** — backfilling is the test. A register that cannot express findings
the project already has is the wrong register, and discovering that after
designing it is the point of doing it in this order.

`make design` (or equivalent) must report: open findings by kind, those
without a reproduction, and those never reported to their owner.

**Done 2026-08-05.** `tools/design.py`, `make design`, and the register in
[`GroundRules.md`](../specs/GroundRules.md) — **14 rows, no new file.**

Backfill was the test. The taxonomy held (five kinds, no sixth), and it
**produced a `role` column ADR-0012 does not have**: the first report
alarmed on U2, wrongly — a green *default* is expected, a green
*counterexample* is the alarm. Folded into GameDesign §1.3. It also
contradicted the survey: **one** U-item names itself in a scenario, not
six. Detail and figures:
[CB-EV-0021](../evidence/CB-EV-0021-the-design-instrument.md) §4, §6.

## Task: report to ground-game, mechanically

```task
id: CB-WP-0022-T06
status: done
priority: high
state_hub_task_id: "c6a659bd-c495-4754-9332-baadad51012a"
```

Generate the report and send it. **The message that sat unread for four
days is the baseline to beat** — the failure was not the message, it was
that nothing pointed at it. So the report lands as a file in `ground-game`
under its own workplan, extending GROUND-WP-0002 rather than duplicating
it.

Include the findings this pass has sharpened:

- **SOLVE's legality** against a face-down Problem or an unmatchable suit —
  and note that the case we *reported* was not the case that fired
  (CB-WP-0023 T01).
- ~~**GR-E01 vs GR-S01** — 4/6/9 against 5/7/9~~ — **withdrawn
  2026-08-05, before sending.** C1 found `2da19a4` had measured **6/9/12**:
  the dataset reconciles them. It would have been the **fourth** wrong
  premise to reach `ground-game` and is the only one caught before
  transmission. **Report the withdrawal** — a claim retracted silently is
  how the first three survived.

**Done 2026-08-05.**
[`ground-game/workplans/GROUND-WP-0002-clay-borg-report-260805.md`](../../ground-game/workplans/GROUND-WP-0002-clay-borg-report-260805.md),
committed there, with a hub message that only *points at* the file.

**The report asks for no ruling.** It carries GR-E01's withdrawal, our own
reproduction debt, and two notes that are explicitly not findings.

**And it acknowledged something the pass did not expect.**
GROUND-WP-0002 is `finished`: **all ten U-items were ruled 2026-08-03**,
every one confirmed as the default we simulate. CB-RES-0007 said *"0 of 10
ruled"* two days later. **The unread-inbox failure running in the opposite
direction** — they answered and we did not collect it. The instrument's
first run surfaced it.

## Task: evidence

```task
id: CB-WP-0022-T07
status: done
priority: high
state_hub_task_id: "4fb77911-486d-4d9e-a53d-c4e486c74ce2"
```

`evidence/CB-EV-0021-*.md`. *(Was CB-EV-0020 when written; CB-WP-0023
shipped that number first — `evidence/CB-EV-0020-solve-legality.md` — so
this one moves rather than collides.)*

- **Whether backfilling changed the design** — if all six findings fit the
  first taxonomy, say so and be suspicious of it.
- **What tier L cost against what it caught**, since this is the second
  full-weight L pass and CB-WP-0012's deleted its own structural trigger.
- **The engine-evolution question**, as the review left it.
- **Quote CB-WP-0021's cost by re-running the instrument.**

**Done 2026-08-05.**
[CB-EV-0021](../evidence/CB-EV-0021-the-design-instrument.md).

**Backfill did change the design** — and the honest answer to *"be
suspicious if all six fit"* is that only **five** were entered (one was a
double-count), so fitting them is close to circular. The taxonomy's real
test is the seventh finding.

**Tier L's cost against what it caught**: four of six catches came only
from the separate reviewer, and **two came from execution rather than
process** — the `role` distinction from building it, the ten uncollected
rulings from running it. That is InnerLoop §Design goal's prediction
holding, and an argument against front-loading more review rather than
less.