diff --git a/wiki/log/decisions/2026-07-27.md b/wiki/log/decisions/2026-07-27.md
index 0574ec3b..399dcb01 100644
--- a/wiki/log/decisions/2026-07-27.md
+++ b/wiki/log/decisions/2026-07-27.md
@@ -187,3 +187,26 @@ Owners: [aggregate-observer.md](../../mechanics/aggregate-observer.md) and
 
 Owners: [plots.md](../../mechanics/plots.md) and
 [social.md](../../mechanics/social.md).
+
+## Addendum: Trace post-hoc review of the self-trust adoption
+
+### DECIDED
+
+- Trace (the cross-session design-history agent) reviewed the landed
+  adoption and found no prior decision it conflicts with. Two boundaries
+  from unwritten history are now pinned in the owning specs:
+  erosion never regresses knowledge (no knowledge-level downgrade, no
+  observer-awareness erasure, no Knowing certainty below its floor of 30),
+  and self-trust is deliberately the only psyche axis — a second
+  independently movable psyche stat reopens the 2026-07-05 minion-depth
+  ("middle") decision rather than extending social.md.
+- A corroborated encounter applies no erosion; this is now explicit in
+  plots.md criterion 12 and social.md pending criterion 9.
+- Trace confirmed the fourth-wall deferral is not only taste: gaslighting
+  the player through false UI would conflict with the honest-interface and
+  continuous-witness laws.
+- Trace holds the eight implementation defense tests in its memory for the
+  runtime review; criterion 12 and criterion 9 carry the binding versions.
+
+Owners: [plots.md](../../mechanics/plots.md) and
+[social.md](../../mechanics/social.md).
diff --git a/wiki/mechanics/plots.md b/wiki/mechanics/plots.md
index ac98cb9a..5f57f848 100644
--- a/wiki/mechanics/plots.md
+++ b/wiki/mechanics/plots.md
@@ -440,7 +440,9 @@ the plot remains held.
     carry a bounded `self_trust` delta that round-trips through save, but a
     negative delta settles only after the exact target encounters the altered
     artifact through its ordinary read boundary without sufficient
-    corroboration. At least one erode-self-trust plot ships; validation rejects
+    corroboration; a corroborated encounter applies no erosion, and no
+    erosion path downgrades knowledge levels, observer awareness, or the
+    Knowing certainty floor. At least one erode-self-trust plot ships; validation rejects
     a definition without tamper, without that target-facing encounter, or
     without a corroboration ending. Its blowback path restores self-trust,
     creates observer-local evidence against the acting persona, and raises
diff --git a/wiki/mechanics/social.md b/wiki/mechanics/social.md
index 1acf0172..68d3565e 100644
--- a/wiki/mechanics/social.md
+++ b/wiki/mechanics/social.md
@@ -107,6 +107,15 @@ cannot be trusted. Rules:
   asset task reliability degrades below their knowledge-level baseline
   [TUNE]. Gaslighting a person and relying on them are in tension by
   design.
+- **Erosion never regresses knowledge.** Low self-trust changes reporting
+  and reliability behavior only. It cannot downgrade a person's knowledge
+  level, erase observer awareness, or lower a Knowing asset's certainty
+  below its permanent floor of 30 — a gaslit Knowing witness doubts what to
+  do about you, never that you exist.
+- **Self-trust is deliberately the only psyche axis.** The 2026-07-05
+  minion-depth decision holds people at middle depth; one sparse,
+  plot-gated axis fits inside it. Proposing a second independently movable
+  psyche stat reopens that decision rather than extending this section.
 - **Corroboration is the recovery path.** Self-trust regrows when the world
   backs the person up: another observer confirms their account, or the
   tamper trace surfaces under audit or intel processing. Discovery also
@@ -292,6 +301,8 @@ retirement, burning, and reopening are bound to the separate PERSONAS view.
    shaken person's own witnessed events convert to suspicion at reduced
    weight and their asset task reliability sits below their knowledge-level
    baseline, while the original event and acquired evidence remain exact.
+   Knowledge levels, observer awareness, and the Knowing certainty floor
+   never regress from erosion. A corroborated encounter applies no erosion.
    Corroboration or tamper-custody discovery restores self-trust and produces
    the ordinary evidence and suspicion blowback. No generic action mutates
    the axis.