diff --git a/skills/agentic-end-to-end-testing/SKILL.md b/skills/agentic-end-to-end-testing/SKILL.md
index 128df3d8..d1e28570 100644
--- a/skills/agentic-end-to-end-testing/SKILL.md
+++ b/skills/agentic-end-to-end-testing/SKILL.md
@@ -51,6 +51,8 @@ Idempotent teardown so reruns are hermetic. Never touch state you didn't create.
 Footguns, timing/ordering caveats, nondeterminism noted while recording.
 ```
 
+When a design spec exists, cards derive from it — see [authoring-cards-from-a-spec.md](authoring-cards-from-a-spec.md); if the spec has an "E2E scenario cards" table, its falsification lines are verbatim contracts.
+
 ## The Run Loop
 
 1. **Preflight.** Build fresh from the code under test — the most common mistake is testing a stale binary. Rebuild every layer your change touches and confirm the running instance is the new one, not a process someone left up yesterday. Isolate hermetically: give the test instance its own HOME, port, and state directory so it can neither collide with nor pollute a real instance. Check credentials and models are in place. Run a minimal smoke check first — one where even a `401` is informative, because it means the server answered.
@@ -113,5 +115,5 @@ All of these mean: stop, run the real thing, look at the real output.
 
 ## Integration
 
-- Runs after superpowers:subagent-driven-development completes a feature, and before superpowers:finishing-a-development-branch decides how the work lands.
+- Runs after superpowers:subagent-driven-development completes a feature — which can end with spec-derived cards authored and run (see authoring-cards-from-a-spec.md) — and before superpowers:finishing-a-development-branch decides how the work lands.
 - Complements superpowers:verification-before-completion: that skill gates any success claim on having run the checks; this one defines what counts as proof when the behavior under test is user-facing.
diff --git a/skills/agentic-end-to-end-testing/authoring-cards-from-a-spec.md b/skills/agentic-end-to-end-testing/authoring-cards-from-a-spec.md
new file mode 100644
index 00000000..abc50c21
--- /dev/null
+++ b/skills/agentic-end-to-end-testing/authoring-cards-from-a-spec.md
@@ -0,0 +1,133 @@
+# Authoring Cards from a Spec
+
+## When to use
+
+A design spec exists and scenario cards are being authored from it — by a
+dispatched card-author subagent (the default; template below) or by the
+coordinator authoring directly. The spec records the *requested* behavior;
+the running app shows only the *built* behavior. Cards written after
+implementation drift toward what was built unless each one is anchored to
+the spec — the anchor is a falsification line lifted from the spec verbatim.
+
+No spec at all? This file doesn't apply — write cards straight from the
+card format in [SKILL.md](SKILL.md) ("The Scenario Card").
+
+## With a scenario table
+
+When the spec carries an "E2E scenario cards" section (a table with Card /
+Covers / Falsification columns), the table is a pre-locked contract:
+
+- **One card per row.** The Card cell names the file
+  (`<cards-dir>/<card>.md`); the Covers cell scopes what it exercises.
+- **The row's Falsification line lands in the card's `## Expected` section
+  VERBATIM.** Re-wrapping across lines is fine — the checker normalizes
+  whitespace — but do not reword, reorder, or "improve" the line. The
+  checker matches it only inside `## Expected`; carrying it anywhere else
+  in the card does not count.
+- **The spec is authoritative wherever the app's behavior disagrees.** Flag
+  the disagreement in the report; never adapt the card to observed
+  behavior. A card that matches the app but not the spec is exactly the
+  drift this file exists to prevent.
+- **Falsification lines are prose contracts, not literal aligned output.**
+  Normalization collapses runs of spaces, so an assertion whose column
+  spacing matters (`TOTAL      20.85`) belongs in the card's Expected body
+  next to the verbatim line — never in the table line itself.
+
+Expand each row into a full card per [SKILL.md](SKILL.md): the
+falsification line is the contract; Pre-state, Steps, and the rest of
+Expected are yours to write, and every assertion you add must itself be
+falsifiable — exact observable values, not "looks right".
+
+## Without a table (bootstrap path)
+
+When the spec has requirements but no "E2E scenario cards" section:
+
+1. Mine the spec's user-visible requirements into discrete behaviors.
+2. Write a falsification line for each — from the spec's wording, not from
+   what the app currently prints.
+3. Add an "E2E scenario cards" section with the table to the spec, carrying
+   those lines. This backport is sanctioned; editing anything else in the
+   spec is not.
+4. Flag the spec edit prominently in the report for human review. Never
+   present a self-written table as a pre-locked contract — the
+   locked-contract guarantee exists only when the table predates
+   implementation. On this path the checker verifies transcription
+   consistency, not pre-implementation locking; say so in the report.
+
+## Coverage check
+
+Before finishing: every user-facing claim in the spec maps to a card, or to
+a stated exclusion with a reason. List the mapping in the report — an
+unmapped claim is uncovered behavior, not an oversight to stay quiet about.
+
+## Role boundary
+
+Verbatim, non-negotiable: the card author never modifies product code, test
+code, or existing cards' assertions. A failing card plus root cause is the
+deliverable, not a fix. One mandate per agent: finders are never fixers —
+fixes belong to a separately dispatched fix wave.
+
+## Mechanical check
+
+After authoring, run the checker (path relative to this skill):
+
+```
+scripts/check-cards-against-spec <spec> <cards-dir>
+```
+
+Include its full output in the report. The dispatching agent re-runs it
+independently before accepting the report — self-attestation is not the
+gate.
+
+## Dispatch template
+
+Fill every `[PLACEHOLDER]`; the author starts with zero conversation
+context. Delete bracketed conditionals that don't apply.
+
+```
+Subagent (general-purpose):
+  description: "Author scenario cards from spec: [SPEC_NAME]"
+  prompt: |
+    You are a scenario-card author. Your only deliverables are cards and a
+    report. This is a cards-only task: the card author never modifies
+    product code, test code, or existing cards' assertions. If a card
+    fails against the app, the failing card plus root cause IS the
+    deliverable — do not fix anything.
+
+    ## The Spec
+
+    Read the spec first: [SPEC_PATH]. It is authoritative — cards assert
+    the requested behavior it records, not whatever the application
+    currently does. If the app's behavior disagrees with the spec, flag
+    the disagreement in your report; never adapt a card to observed
+    behavior.
+
+    ## The Cards
+
+    - Write one card per row of the spec's "E2E scenario cards" table
+      into [CARDS_DIR], using the card format in [SKILL_DIR]/SKILL.md
+      ("The Scenario Card" section).
+    - Each card's ## Expected section must carry its row's Falsification
+      line VERBATIM — re-wrap freely, never reword.
+    - [If the spec has no table: follow the bootstrap path in
+      [SKILL_DIR]/authoring-cards-from-a-spec.md — derive falsification
+      lines from the spec's requirements, backport the table into the
+      spec, and flag the spec edit prominently in your report.]
+
+    ## Mechanical check
+
+    Run [SKILL_DIR]/scripts/check-cards-against-spec [SPEC_PATH]
+    [CARDS_DIR] and include its full output in your report. I re-run it
+    independently — your report is not the gate.
+
+    ## Report
+
+    Your final message, in this exact shape:
+    1. Cards written (paths).
+    2. Per card: falsification source (table row / bootstrap).
+    3. Coverage: each user-facing spec claim -> card, or a stated
+       exclusion with a reason.
+    4. Checker output, complete and unedited.
+    5. Spec disagreements: app-vs-spec divergences, flagged.
+    6. [Bootstrap only] Spec edits made, flagged for human review.
+```