Guard Duke grants using public capture uncertainty

docs/CURRENT_STATUS.md

@@ -17,6 +17,16 @@ open mode gates.
 
 ## Current checkpoint and work
 
+**Duke Ambassador capture uncertainty — 29 October. Prototyped / Partial.**
+Fresh games track whether a public Harkonnen capture could have involved Duke,
+independent of the secret selection. When capture history is uncertain, direct
+acquisition and the automatic alliance loan are uniformly guarded; unstamped
+older games remain conservative. A plain Advanced Ecaz–Harkonnen game can use
+both grants while its public history rules out capture. Eight related files pass
+62 cases, including real setup and capture; broader combinations, resolving
+uncertainty later, and deployed verification remain open.
+[Scope](ECAZ_DUKE_ACQUISITION.md#public-capture-uncertainty--29-october-2026).
+
 **Concealed Duke and Ghola guidance — 29 October. Prototyped / Partial.**
 Ecaz's Ghola choices now use the same projected Duke state as ordinary revival,
 so secretly executing another player's Duke captive no longer changes that

docs/DUKE_VIDAL_RULES.md

@@ -17,7 +17,10 @@ admitted Advanced Harkonnen profiles, the Ambassador acquisition descriptor
 uses actual Duke custody and may distinguish a secretly captured Duke from a
 publicly equivalent free Duke. Plain Advanced Ecaz/Harkonnen acquisition stays
 guarded until a public-safe solution is implemented. Broader capture assurance
-and deployed verification remain open.
+and deployed verification remain open. The later [public capture uncertainty
+policy](ECAZ_DUKE_ACQUISITION.md#public-capture-uncertainty--29-october-2026)
+guards the Ambassador availability issue described above, with explicit
+legacy and post-capture limitations.
 
 ## Occupied Ecaz grant — 26 October 2026
 

docs/ECAZ_DUKE_ACQUISITION.md

@@ -1,5 +1,32 @@
 # Ecaz Ambassador: direct Duke acquisition
 
+## Public capture uncertainty — 29 October 2026
+
+**Prototyped / Partial.** A fresh game records whether a public Harkonnen
+capture could have involved Duke, using the losing player's public identity,
+revealed battle plan and projected Duke controller, never the selected captive.
+Once that possibility arises it stays recorded. Direct Ambassador acquisition
+and the automatic Advanced alliance loan are uniformly unavailable while the
+record is uncertain, regardless of actual hidden custody. A game saved before
+this receipt existed is also treated conservatively: its truncated history
+cannot prove that a concealed capture never occurred. No saved game is reset
+or retroactively assigned a fabricated clean history.
+
+When the record is clear, a plain Advanced Ecaz–Harkonnen game can use the
+ordinary direct grant and automatic new-ally loan; the original disc, reusable
+token, existing custody checks and continuation remain. The same public
+uncertainty guard protects already supported Harkonnen profiles. This
+conservative restriction can block an otherwise available Duke after a
+possible capture and currently does not clear itself; it is a provisional
+online policy, not a publisher ruling. A more complete public resolution of
+uncertainty, broader modules and old-game coverage remain open.
+
+Eight related files pass 62 cases. Genuine plain Advanced setup exercises both
+grants, and an actual capture is replayed with controlled shuffle outcomes to
+confirm the same receipt for Duke and another leader. The equivalent-custody
+privacy comparison stages the two physical underlays. Deployed verification
+and comprehensive capture assurance remain open.
+
 ## Same-recipient temporary tenure — 27 October 2026
 
 **Prototyped / Partial.** At an actual eligible Ecaz Ambassador entry, Ecaz may

docs/RULE_DECISIONS.md

@@ -1,5 +1,13 @@
 # Rule decision index
 
+## Duke Ambassador capture uncertainty — 29 October 2026
+
+Fresh games record whether a public capture could have involved Duke, without
+using the secret selection. Direct acquisition and automatic alliance loan
+are uniformly guarded while that history is uncertain; legacy games without
+the receipt remain conservative. This is a provisional online policy.
+[Scope](ECAZ_DUKE_ACQUISITION.md#public-capture-uncertainty--29-october-2026).
+
 ## Concealed Duke and Ghola guidance — 29 October 2026
 
 Ecaz's Ghola guidance uses its projected Duke state, matching ordinary revival;