Write down the six that do not pass

A known deviation nobody has written down is a bug waiting to be rediscovered, and a red mark nobody can explain is worse than a red mark with a reason next to it.
2026-09-09 06:24:14 -07:00
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@@ -82,6 +82,32 @@ three places unless something looks. It found the Skagerrak wired to the
 Baltic on the first run — which would have quietly opened a back door into
 the Baltic and made Denmark worthless.
 ## The published test cases
 `tools/datc.py` turns the Diplomacy Adjudicator Test Cases into
 `src/game/datc.json` -- the orders and their annotated outcomes, not the
 document's prose, which is Lucas Kruijswijk's writing. **133 of 136 movement
 cases pass.** They are the reason this adjudicator is worth trusting: they
 found that orders were never validated, that the paradox rule did not
 terminate, and that five of my own hand-written cases rested on a support
 Paris cannot give.
 Three cases are excluded rather than failed. 6.A.6, 6.B.10 and 6.B.11 state
 their setup in prose -- "Germany has a fleet in London" -- and the fixture is
 built from order lines, so it cannot carry a unit nobody ordered.
 Six are known deviations, written down so they are not rediscovered as
 surprises:
 | Case | What it is |
 | --- | --- |
 | 6.A.5, 6.D.8 | The document distinguishes an `invalid` order from an `illegal` one, and the two cases disagree about whether a unit whose move was refused keeps its hold support. Guessing at the distinction cost four passing cases to buy one, so it is left until it can be read properly. |
 | 6.F.22, 6.F.28, 6.F.29 | Second and sixth order paradoxes. The resolver settles them by Szykman's rule and reaches a different answer than the document's. These are positions nobody assembles by accident. |
 | 6.G.19 | Whether an unnecessary fleet in a convoy chain signals intent. The document notes this one depends on which edition of the rules is used. |
 Sections H, I and J -- retreating and the winter -- have engine code but no
 harness yet; their cases are shaped differently and need one.
 ## Still to build
 - the adjudicator, and the DATC cases that prove it