diff --git a/CLAUDE.md b/CLAUDE.md
index 571755d..b242fd4 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -178,6 +178,25 @@ CLI-driven iteration.
 
 ---
 
+## Code Changes 
+
+When making bulk renames or refactors, do NOT make unrequested additional renames. Only change what was explicitly asked for. If you think something else should be renamed, ask first.
+
+---
+
+## Interaction Style 
+
+When working through a list of items (issues, review findings, renames), present them one at a time and wait for user input before proceeding to the next.
+
+
+---
+
+## Problem Solving 
+
+When fixing build errors or investigating issues, always research the root cause before attempting a fix. Do not apply quick fixes without understanding the underlying problem (e.g., platform availability, import visibility rules).
+
+---
+
 ## Testing
 
 Tests use **Swift Testing** (`import Testing`), not XCTest.
@@ -188,6 +207,7 @@ Test coverage priorities:
 3. `Compendium` loading and lookup correctness
 4. UI flows for encounter setup and live tracking (UITests)
 
+Always run a clean build and full test suite after making changes. Never reuse stale test output or cached build results. Use `swift build` and `swift test` fresh each time.
 ---
 
 ## Architecture Decision Records
diff --git a/Encounter/Views/AdversaryRunnerCard.swift b/Encounter/Views/AdversaryRunnerCard.swift
index 1ec8cc9..8761471 100644
--- a/Encounter/Views/AdversaryRunnerCard.swift
+++ b/Encounter/Views/AdversaryRunnerCard.swift
@@ -22,6 +22,11 @@ struct AdversaryRunnerCard: View {
   let compendium: Compendium
   let onCollapse: () -> Void
 
+  @State private var isEditingName = false
+  @State private var pendingName = ""
+  @State private var nameError: String?
+  @FocusState private var isNameFieldFocused: Bool
+
   private var displayName: String {
     let adversary = compendium.adversary(id: slot.adversaryID)
     return slot.customName ?? adversary?.name ?? "Unknown (\(slot.adversaryID))"
@@ -36,13 +41,39 @@ struct AdversaryRunnerCard: View {
 
       // Header
       HStack {
-        Text(displayName)
-          .font(.headline)
-        Spacer()
-        Button("Collapse", systemImage: "chevron.up", action: onCollapse)
-          .labelStyle(.iconOnly)
-          .buttonStyle(.borderless)
-          .accessibilityIdentifier("runner.adversary-card.collapse-button")
+        if isEditingName {
+          TextField("Name", text: $pendingName)
+            .font(.headline)
+            .focused($isNameFieldFocused)
+            .onSubmit { commitRename() }
+            .accessibilityIdentifier("runner.adversary-card.name-field")
+          Button("Done") { commitRename() }
+            .buttonStyle(.borderless)
+            .accessibilityIdentifier("runner.adversary-card.rename-done-button")
+          Button("Cancel") { cancelRename() }
+            .buttonStyle(.borderless)
+            .accessibilityIdentifier("runner.adversary-card.rename-cancel-button")
+        } else {
+          Button(action: beginRename) {
+            Text(displayName)
+              .font(.headline)
+              .foregroundStyle(.primary)
+          }
+          .buttonStyle(.plain)
+          .accessibilityIdentifier("runner.adversary-card.name")
+          .accessibilityHint("Tap to rename")
+          Spacer()
+          Button("Collapse", systemImage: "chevron.up", action: onCollapse)
+            .labelStyle(.iconOnly)
+            .buttonStyle(.borderless)
+            .accessibilityIdentifier("runner.adversary-card.collapse-button")
+        }
+      }
+      if isEditingName, let error = nameError {
+        Text(error)
+          .font(.caption)
+          .foregroundStyle(.red)
+          .accessibilityIdentifier("runner.adversary-card.name-error")
       }
 
       // HP pip track
@@ -93,6 +124,34 @@ struct AdversaryRunnerCard: View {
     }
     .padding(.vertical, 8)
   }
+
+  private func beginRename() {
+    pendingName = displayName
+    nameError = nil
+    isEditingName = true
+    isNameFieldFocused = true
+  }
+
+  private func commitRename() {
+    let trimmed = pendingName.trimmingCharacters(in: .whitespaces)
+    guard !trimmed.isEmpty else {
+      cancelRename()
+      return
+    }
+    if session.renameAdversary(id: slot.id, name: trimmed) {
+      isNameFieldFocused = false
+      isEditingName = false
+      nameError = nil
+    } else {
+      nameError = "Name already in use"
+    }
+  }
+
+  private func cancelRename() {
+    isNameFieldFocused = false
+    isEditingName = false
+    nameError = nil
+  }
 }
 
 #Preview {
diff --git a/Encounter/Views/AdversaryRunnerSection.swift b/Encounter/Views/AdversaryRunnerSection.swift
index 9a7b897..5de0c68 100644
--- a/Encounter/Views/AdversaryRunnerSection.swift
+++ b/Encounter/Views/AdversaryRunnerSection.swift
@@ -39,9 +39,19 @@ struct AdversaryRunnerSection: View {
         .disabled(slot.isDefeated)
         .accessibilityIdentifier("runner.adversary-row")
         .accessibilityLabel(
-          slot.isDefeated
-            ? "\(slot.customName ?? slot.adversaryID), defeated"
-            : (slot.customName ?? slot.adversaryID)
+          {
+            let name = slot.customName ?? slot.adversaryID
+            var parts: [String] = [name]
+            if slot.isDefeated {
+              parts.append("defeated")
+            }
+            if !slot.conditions.isEmpty {
+              let conditionNames = slot.conditions.map(\.displayName).sorted().joined(
+                separator: ", ")
+              parts.append("Conditions: \(conditionNames)")
+            }
+            return parts.joined(separator: ", ")
+          }()
         )
         .accessibilityHint(slot.isDefeated ? "" : "Tap to expand")
       }
diff --git a/EncounterTests/EncounterTests.swift b/EncounterTests/EncounterTests.swift
index 06bb158..1009746 100644
--- a/EncounterTests/EncounterTests.swift
+++ b/EncounterTests/EncounterTests.swift
@@ -263,6 +263,57 @@ struct ConditionTests {
     #expect(session.adversarySlots[0].isDefeated == false)
   }
 
+  // MARK: - Rename
+
+  @Test func renameAdversary_success() {
+    let session = makeSession()
+    let soldier = makeSoldier()
+    session.add(adversary: soldier, customName: "Alpha")
+    session.add(adversary: soldier, customName: "Bravo")
+    let id = session.adversarySlots[0].id
+
+    let result = session.renameAdversary(id: id, name: "Charlie")
+
+    #expect(result == true)
+    #expect(session.adversarySlots[0].customName == "Charlie")
+  }
+
+  @Test func renameAdversary_duplicate() {
+    let session = makeSession()
+    let soldier = makeSoldier()
+    session.add(adversary: soldier, customName: "Alpha")
+    session.add(adversary: soldier, customName: "Bravo")
+    let id = session.adversarySlots[0].id
+
+    let result = session.renameAdversary(id: id, name: "Bravo")
+
+    #expect(result == false)
+    #expect(session.adversarySlots[0].customName == "Alpha")
+  }
+
+  @Test func renameAdversary_emptyName() {
+    let session = makeSession()
+    let soldier = makeSoldier()
+    session.add(adversary: soldier, customName: "Alpha")
+    let id = session.adversarySlots[0].id
+
+    #expect(session.renameAdversary(id: id, name: "") == false)
+    #expect(session.renameAdversary(id: id, name: "   ") == false)
+    #expect(session.adversarySlots[0].customName == "Alpha")
+  }
+
+  @Test func renameAdversary_selfNameAllowed() {
+    let session = makeSession()
+    let soldier = makeSoldier()
+    session.add(adversary: soldier, customName: "Alpha")
+    let id = session.adversarySlots[0].id
+
+    let result = session.renameAdversary(id: id, name: "Alpha")
+
+    #expect(result == true)
+    #expect(session.adversarySlots[0].customName == "Alpha")
+  }
+
   @Test func applyDamageReducesHP() {
     let session = makeSession()
     let soldier = makeSoldier()
@@ -367,7 +418,6 @@ struct ConditionTests {
     #expect(session.adversarySlots[0].conditions.contains(.custom("Enraged")))
   }
 
-
 }
 
 // MARK: - PlayerState
diff --git a/EncounterUITests/AccessibilityTreeDump.swift b/EncounterUITests/AccessibilityTreeDump.swift
index 0b726fc..69ec10d 100644
--- a/EncounterUITests/AccessibilityTreeDump.swift
+++ b/EncounterUITests/AccessibilityTreeDump.swift
@@ -108,7 +108,8 @@ final class AccessibilityTreeDump: XCTestCase {
     let createButton = app.buttons.matching(identifier: "library.create-button").firstMatch
     XCTAssertTrue(createButton.waitForExistence(timeout: 3), "library.create-button not found")
     XCTAssertTrue(createButton.isEnabled, "Create button should be enabled")
-    let result = "library.create-button found: true, enabled: \(createButton.isEnabled), frame: \(createButton.frame)\n"
+    let result =
+      "library.create-button found: true, enabled: \(createButton.isEnabled), frame: \(createButton.frame)\n"
     try? result.write(toFile: "/tmp/library_create_button.txt", atomically: true, encoding: .utf8)
   }
 
diff --git a/EncounterUITests/EncounterUITestCase.swift b/EncounterUITests/EncounterUITestCase.swift
new file mode 100644
index 0000000..340e740
--- /dev/null
+++ b/EncounterUITests/EncounterUITestCase.swift
@@ -0,0 +1,195 @@
+//
+//  EncounterUITestCase.swift
+//  EncounterUITests
+//
+//  Base class for Encounter UI tests. Provides shared setUp, navigation
+//  helpers, and form utilities so test classes don't duplicate this logic.
+//
+
+import XCTest
+
+class EncounterUITestCase: XCTestCase {
+
+  var app: XCUIApplication!
+
+  override func setUpWithError() throws {
+    continueAfterFailure = false
+    app = XCUIApplication()
+    app.launchArguments = ["-UITestResetState"]
+    app.launch()
+    XCTAssertTrue(
+      app.navigationBars["Party"].waitForExistence(timeout: 10),
+      "App should load and show Party screen within 10 seconds")
+  }
+
+  // MARK: - Top-level navigation flows
+
+  /// Navigates from the Party screen all the way into the live encounter runner.
+  ///
+  /// Flow:
+  ///   1. Add one player (required for "Run Encounter" to be enabled).
+  ///   2. Switch to Encounters tab.
+  ///   3. Create a new encounter.
+  ///   4. Open the encounter in the builder.
+  ///   5. Add one adversary from the compendium.
+  ///   6. Tap "Run Encounter".
+  func navigateToRunner() {
+    addOnePlayer()
+    switchToEncountersTab()
+    createEncounter()
+    openFirstEncounter()
+    addAdversaryFromCompendium()
+    tapRunEncounter()
+  }
+
+  /// Same as `navigateToRunner`, but adds the same (first) adversary twice so
+  /// both slots receive auto-assigned `customName` values ("Name 1", "Name 2").
+  func navigateToRunnerWithTwoSameAdversaries() {
+    addOnePlayer()
+    switchToEncountersTab()
+    createEncounter()
+    openFirstEncounter()
+    addAdversaryFromCompendium()
+    addAdversaryFromCompendium()
+    tapRunEncounter()
+  }
+
+  /// Expands the first adversary row in the runner.
+  func expandFirstCard() {
+    let row = app.buttons.matching(identifier: "runner.adversary-row").firstMatch
+    XCTAssertTrue(row.waitForExistence(timeout: 5), "Adversary row should be in runner")
+    row.tap()
+    XCTAssertTrue(
+      app.buttons["runner.adversary-card.collapse-button"].waitForExistence(timeout: 3),
+      "Card should expand after tapping row")
+  }
+
+  // MARK: - Step helpers
+
+  func addOnePlayer(
+    name: String = "Aric", hp: String = "6", stress: String = "6",
+    evasion: String = "12", major: String = "5", severe: String = "10", armor: String = "3"
+  ) {
+    app.buttons["party.add-player-button"].tap()
+    XCTAssertTrue(
+      app.textFields["party.form.name-field"].waitForExistence(timeout: 3),
+      "Player form should appear")
+    fillPlayerForm(
+      name: name, hp: hp, stress: stress, evasion: evasion,
+      major: major, severe: severe, armor: armor)
+    app.buttons["party.form.commit-button"].tap()
+    XCTAssertTrue(
+      app.buttons.matching(identifier: "party.active-row").firstMatch
+        .waitForExistence(timeout: 5),
+      "Player should appear in active party")
+  }
+
+  func switchToEncountersTab() {
+    let tab = app.tabBars.buttons["Encounters"]
+    XCTAssertTrue(tab.waitForExistence(timeout: 3))
+    tab.tap()
+    XCTAssertTrue(
+      app.navigationBars["Encounters"].waitForExistence(timeout: 5),
+      "Encounters screen should appear")
+  }
+
+  func createEncounter() {
+    let createButton = app.buttons.matching(identifier: "library.create-button").firstMatch
+    XCTAssertTrue(createButton.waitForExistence(timeout: 3))
+    createButton.tap()
+    let confirm = app.alerts["New Encounter"].buttons["Create"]
+    XCTAssertTrue(confirm.waitForExistence(timeout: 3))
+    confirm.tap()
+  }
+
+  func openFirstEncounter() {
+    let row = app.buttons.matching(identifier: "library.row").firstMatch
+    XCTAssertTrue(row.waitForExistence(timeout: 5))
+    row.tap()
+  }
+
+  /// Opens the compendium browser, taps the first adversary, and adds it.
+  /// Uses the in-form "Add" button (builder.add-adversary-button) rather than the
+  /// toolbar button, because on iOS 26 with .toolbarRole(.editor) the toolbar items
+  /// collapse into an overflow "More" menu and are not directly hittable.
+  /// The sheet auto-dismisses via `showCompendium = false` in the builder's `onSelect` closure.
+  func addAdversaryFromCompendium() {
+    let addButton = app.buttons["builder.add-adversary-button"]
+    XCTAssertTrue(
+      addButton.waitForExistence(timeout: 5), "Add adversary button should be visible")
+    addButton.tap()
+
+    let firstRow = app.buttons.matching(identifier: "compendium.adversary-row").firstMatch
+    XCTAssertTrue(firstRow.waitForExistence(timeout: 5), "Compendium adversary list should appear")
+    firstRow.tap()
+
+    let addToEncounterButton = app.buttons["compendium.add-to-encounter-button"]
+    XCTAssertTrue(
+      addToEncounterButton.waitForExistence(timeout: 5), "Add to Encounter button should appear")
+    addToEncounterButton.tap()
+
+    // Sheet auto-closes; wait for the add button to confirm we're back on the builder.
+    XCTAssertTrue(
+      addButton.waitForExistence(timeout: 5),
+      "Builder should be visible after compendium sheet dismisses")
+  }
+
+  func tapRunEncounter() {
+    // On iOS 26 with .toolbarRole(.editor), the Run Encounter button is in the toolbar
+    // overflow menu (OverflowBarButtonItem / "More"). Menu items lose their AX identifiers
+    // and are only findable by label once the menu is open.
+    let overflowButton = app.buttons["OverflowBarButtonItem"]
+    XCTAssertTrue(
+      overflowButton.waitForExistence(timeout: 5), "Toolbar overflow button should be visible")
+    overflowButton.tap()
+
+    let runButton = app.buttons["Run Encounter"]
+    XCTAssertTrue(
+      runButton.waitForExistence(timeout: 3), "Run Encounter button should appear in overflow menu")
+    XCTAssertTrue(runButton.isEnabled, "Run Encounter button should be enabled")
+    runButton.tap()
+    XCTAssertTrue(
+      app.collectionViews["runner.adversary-list"].waitForExistence(timeout: 5),
+      "Runner adversary list should appear")
+  }
+
+  // MARK: - Form helpers
+
+  func fillPlayerForm(
+    name: String, hp: String, stress: String, evasion: String,
+    major: String, severe: String, armor: String
+  ) {
+    let fields: [(String, String)] = [
+      ("party.form.name-field", name),
+      ("party.form.max-hp-field", hp),
+      ("party.form.max-stress-field", stress),
+      ("party.form.evasion-field", evasion),
+      ("party.form.threshold-major-field", major),
+      ("party.form.threshold-severe-field", severe),
+      ("party.form.armor-slots-field", armor),
+    ]
+    for (id, value) in fields {
+      let field = app.textFields[id]
+      field.tap()
+      field.typeText(value)
+    }
+  }
+
+  /// Replaces the text field's current value with `text`.
+  /// Selects all existing text, then types the replacement (or deletes if empty).
+  func replaceText(in field: XCUIElement, with text: String) {
+    #if os(iOS)
+      // Triple-tap selects all text in a UITextField. Works whether the field is
+      // already focused (via @FocusState) or not — no prior single-tap needed.
+      field.tap(withNumberOfTaps: 3, numberOfTouches: 1)
+    #else
+      field.tap()
+      field.typeKey("a", modifierFlags: .command)
+    #endif
+    if text.isEmpty {
+      field.typeText(XCUIKeyboardKey.delete.rawValue)
+    } else {
+      field.typeText(text)
+    }
+  }
+}
diff --git a/EncounterUITests/PartyManagementUITests.swift b/EncounterUITests/PartyManagementUITests.swift
index 25e4505..cdf48af 100644
--- a/EncounterUITests/PartyManagementUITests.swift
+++ b/EncounterUITests/PartyManagementUITests.swift
@@ -92,8 +92,9 @@ final class PartyManagementUITests: XCTestCase {
     // stepper is still on-screen and the number-pad keyboard is not yet showing.
     incrementLevel(by: 2)
 
-    fillForm(name: "Aric", hp: "6", stress: "6", evasion: "12",
-             major: "5", severe: "10", armor: "3")
+    fillForm(
+      name: "Aric", hp: "6", stress: "6", evasion: "12",
+      major: "5", severe: "10", armor: "3")
     app.buttons["party.form.commit-button"].tap()
 
     // The active-party row Button's accessibility label is the concatenation of
@@ -116,8 +117,9 @@ final class PartyManagementUITests: XCTestCase {
 
     // Set level to 5 (Tier 3) before filling text fields.
     incrementLevel(by: 4)
-    fillForm(name: "Lira", hp: "5", stress: "7", evasion: "14",
-             major: "4", severe: "8", armor: "2")
+    fillForm(
+      name: "Lira", hp: "5", stress: "7", evasion: "14",
+      major: "4", severe: "8", armor: "2")
     app.buttons["party.form.commit-button"].tap()
 
     // Open the edit form by tapping the party row.
@@ -127,7 +129,8 @@ final class PartyManagementUITests: XCTestCase {
 
     // Verify the edit form shows level 5.
     let stepper = app.steppers["party.form.level-stepper"]
-    XCTAssertTrue(stepper.waitForExistence(timeout: 3), "Level stepper should be visible in edit form")
+    XCTAssertTrue(
+      stepper.waitForExistence(timeout: 3), "Level stepper should be visible in edit form")
     XCTAssertEqual(stepper.value as? String, "5", "Edit form should show the saved level of 5")
   }
 
@@ -142,8 +145,9 @@ final class PartyManagementUITests: XCTestCase {
       app.textFields["party.form.name-field"].waitForExistence(timeout: 3),
       "Player form sheet should appear after tapping Add Player")
 
-    fillForm(name: "Aric", hp: "6", stress: "6", evasion: "12",
-             major: "5", severe: "10", armor: "3")
+    fillForm(
+      name: "Aric", hp: "6", stress: "6", evasion: "12",
+      major: "5", severe: "10", armor: "3")
 
     // The Add Another button sits in a safeAreaInset outside the Form scroll view so
     // it is always pinned above the number pad keyboard — no keyboard dismissal step
@@ -174,14 +178,16 @@ final class PartyManagementUITests: XCTestCase {
     // returns the placeholder text as the element's value — so "empty" means
     // value == placeholderValue, not value == "".
     let nameField = app.textFields["party.form.name-field"]
-    XCTAssertTrue(nameField.waitForExistence(timeout: 3), "Name field should be visible after scrolling to top")
+    XCTAssertTrue(
+      nameField.waitForExistence(timeout: 3), "Name field should be visible after scrolling to top")
     XCTAssertEqual(
       nameField.value as? String, nameField.placeholderValue,
       "Name field should be empty (showing placeholder) after Add Another resets the form")
 
     // Fill the second player and commit.
-    fillForm(name: "Lira", hp: "5", stress: "7", evasion: "14",
-             major: "4", severe: "8", armor: "2")
+    fillForm(
+      name: "Lira", hp: "5", stress: "7", evasion: "14",
+      major: "4", severe: "8", armor: "2")
     app.buttons["party.form.commit-button"].tap()
 
     // Both players must appear as active-party rows.
@@ -196,8 +202,9 @@ final class PartyManagementUITests: XCTestCase {
   /// Encounter builder after the user switches tabs and opens a builder.
   @MainActor
   func testPartyMembersVisibleInBuilderRoster() throws {
-    addOnePlayer(name: "Aric", hp: "6", stress: "6", evasion: "12",
-                 major: "5", severe: "10", armor: "3")
+    addOnePlayer(
+      name: "Aric", hp: "6", stress: "6", evasion: "12",
+      major: "5", severe: "10", armor: "3")
 
     // Switch to Encounters tab.
     let encountersTab = app.tabBars.buttons["Encounters"]
@@ -281,8 +288,9 @@ final class PartyManagementUITests: XCTestCase {
   ) {
     app.buttons["party.add-player-button"].tap()
     _ = app.textFields["party.form.name-field"].waitForExistence(timeout: 3)
-    fillForm(name: name, hp: hp, stress: stress, evasion: evasion,
-             major: major, severe: severe, armor: armor)
+    fillForm(
+      name: name, hp: hp, stress: stress, evasion: evasion,
+      major: major, severe: severe, armor: armor)
     app.buttons["party.form.commit-button"].tap()
     _ = app.buttons.matching(identifier: "party.active-row").firstMatch
       .waitForExistence(timeout: 5)
diff --git a/EncounterUITests/RenameAdversaryUITests.swift b/EncounterUITests/RenameAdversaryUITests.swift
new file mode 100644
index 0000000..01e9b47
--- /dev/null
+++ b/EncounterUITests/RenameAdversaryUITests.swift
@@ -0,0 +1,185 @@
+//
+//  RenameAdversaryUITests.swift
+//  EncounterUITests
+//
+//  Covers the PR #76 test plan: editable adversary name in runner.
+//  Items verified:
+//   1. Tap name in expanded card → TextField appears pre-filled
+//   2. Type unique name, tap Done → card and collapsed row both update
+//   3. Press Return → same as Done
+//   4. Type name already in use → inline error appears
+//   5. Clear field, tap Done → silently reverts
+//   6. Tap Cancel → reverts without error
+//   7. Collapse button accessible in normal (non-editing) state
+//
+
+import XCTest
+
+final class RenameAdversaryUITests: EncounterUITestCase {
+
+  // MARK: - Test Plan Item 7: Collapse button accessible in normal state
+
+  func testCollapseButtonAccessibleBeforeEditing() {
+    navigateToRunner()
+    expandFirstCard()
+
+    let collapseButton = app.buttons["runner.adversary-card.collapse-button"]
+    XCTAssertTrue(
+      collapseButton.waitForExistence(timeout: 3),
+      "Collapse button should be visible in the card header")
+    XCTAssertTrue(collapseButton.isHittable, "Collapse button should be tappable")
+  }
+
+  // MARK: - Test Plan Item 1: Tap name → TextField appears pre-filled
+
+  func testTapNameShowsPrefilledTextField() {
+    navigateToRunner()
+    expandFirstCard()
+
+    let nameButton = app.buttons["runner.adversary-card.name"]
+    XCTAssertTrue(nameButton.waitForExistence(timeout: 3), "Name button should be visible")
+    let preFilled = nameButton.label
+    XCTAssertFalse(preFilled.isEmpty, "Name button should have a non-empty label")
+
+    nameButton.tap()
+
+    let nameField = app.textFields["runner.adversary-card.name-field"]
+    XCTAssertTrue(nameField.waitForExistence(timeout: 2), "Name field should appear")
+    XCTAssertEqual(
+      nameField.value as? String, preFilled,
+      "Name field should be pre-filled with the current name")
+  }
+
+  // MARK: - Test Plan Item 2: Unique rename → Done → both views update
+
+  func testRenameViaDoneButtonUpdatesDisplay() {
+    navigateToRunner()
+    expandFirstCard()
+
+    app.buttons["runner.adversary-card.name"].tap()
+
+    let nameField = app.textFields["runner.adversary-card.name-field"]
+    XCTAssertTrue(nameField.waitForExistence(timeout: 2))
+    replaceText(in: nameField, with: "Grimfang")
+
+    app.buttons["runner.adversary-card.rename-done-button"].tap()
+
+    // Card header should show the new name.
+    let nameButton = app.buttons["runner.adversary-card.name"]
+    XCTAssertTrue(nameButton.waitForExistence(timeout: 2))
+    XCTAssertEqual(nameButton.label, "Grimfang", "Card header should show new name")
+
+    // Collapsed row label also updates (collapse first to expose the row).
+    app.buttons["runner.adversary-card.collapse-button"].tap()
+    let row = app.buttons.matching(identifier: "runner.adversary-row").firstMatch
+    XCTAssertTrue(row.waitForExistence(timeout: 2))
+    XCTAssertEqual(row.label, "Grimfang", "Collapsed row accessibility label should show new name")
+  }
+
+  // MARK: - Test Plan Item 3: Return key commits rename
+
+  func testReturnKeyCommitsRename() {
+    navigateToRunner()
+    expandFirstCard()
+
+    app.buttons["runner.adversary-card.name"].tap()
+
+    let nameField = app.textFields["runner.adversary-card.name-field"]
+    XCTAssertTrue(nameField.waitForExistence(timeout: 2))
+    replaceText(in: nameField, with: "Shadowclaw")
+
+    nameField.typeText("\n")
+
+    let nameButton = app.buttons["runner.adversary-card.name"]
+    XCTAssertTrue(nameButton.waitForExistence(timeout: 2))
+    XCTAssertEqual(nameButton.label, "Shadowclaw", "Return key should commit the rename")
+  }
+
+  // MARK: - Test Plan Item 5: Clear field → Done → silent revert
+
+  func testEmptyFieldReverts() {
+    navigateToRunner()
+    expandFirstCard()
+
+    let nameButton = app.buttons["runner.adversary-card.name"]
+    XCTAssertTrue(nameButton.waitForExistence(timeout: 3))
+    let originalName = nameButton.label
+
+    nameButton.tap()
+
+    let nameField = app.textFields["runner.adversary-card.name-field"]
+    XCTAssertTrue(nameField.waitForExistence(timeout: 2))
+    replaceText(in: nameField, with: "")
+
+    app.buttons["runner.adversary-card.rename-done-button"].tap()
+
+    let nameButtonAfter = app.buttons["runner.adversary-card.name"]
+    XCTAssertTrue(nameButtonAfter.waitForExistence(timeout: 2))
+    XCTAssertEqual(
+      nameButtonAfter.label, originalName,
+      "Empty commit should revert to original name")
+    XCTAssertFalse(
+      app.staticTexts["runner.adversary-card.name-error"].exists,
+      "No error should appear for empty-field revert")
+  }
+
+  // MARK: - Test Plan Item 6: Cancel → reverts without error
+
+  func testCancelReverts() {
+    navigateToRunner()
+    expandFirstCard()
+
+    let nameButton = app.buttons["runner.adversary-card.name"]
+    XCTAssertTrue(nameButton.waitForExistence(timeout: 3))
+    let originalName = nameButton.label
+
+    nameButton.tap()
+
+    let nameField = app.textFields["runner.adversary-card.name-field"]
+    XCTAssertTrue(nameField.waitForExistence(timeout: 2))
+    replaceText(in: nameField, with: "SomethingElse")
+
+    app.buttons["runner.adversary-card.rename-cancel-button"].tap()
+
+    let nameButtonAfter = app.buttons["runner.adversary-card.name"]
+    XCTAssertTrue(nameButtonAfter.waitForExistence(timeout: 2))
+    XCTAssertEqual(nameButtonAfter.label, originalName, "Cancel should revert to original name")
+    XCTAssertFalse(
+      app.staticTexts["runner.adversary-card.name-error"].exists,
+      "No error should appear after Cancel")
+  }
+
+  // MARK: - Test Plan Item 4: Duplicate name → inline error
+
+  func testDuplicateNameShowsError() {
+    navigateToRunnerWithTwoSameAdversaries()
+
+    let rows = app.buttons.matching(identifier: "runner.adversary-row")
+    XCTAssertTrue(
+      rows.element(boundBy: 1).waitForExistence(timeout: 5), "Two adversary rows expected")
+
+    // Get the second slot's display name (its accessibility label = customName).
+    let secondSlotName = rows.element(boundBy: 1).label
+
+    // Expand the first row.
+    rows.firstMatch.tap()
+
+    let nameButton = app.buttons["runner.adversary-card.name"]
+    XCTAssertTrue(nameButton.waitForExistence(timeout: 3))
+    nameButton.tap()
+
+    let nameField = app.textFields["runner.adversary-card.name-field"]
+    XCTAssertTrue(nameField.waitForExistence(timeout: 2))
+    replaceText(in: nameField, with: secondSlotName)
+
+    app.buttons["runner.adversary-card.rename-done-button"].tap()
+
+    let errorLabel = app.staticTexts["runner.adversary-card.name-error"]
+    XCTAssertTrue(errorLabel.waitForExistence(timeout: 2), "Inline error should appear")
+    XCTAssertEqual(errorLabel.label, "Name already in use")
+
+    XCTAssertTrue(
+      app.textFields["runner.adversary-card.name-field"].exists,
+      "Name field should stay visible after rejected rename")
+  }
+}
diff --git a/EncounterUITests/RunnerUITests.swift b/EncounterUITests/RunnerUITests.swift
index 6e0a86c..d146e28 100644
--- a/EncounterUITests/RunnerUITests.swift
+++ b/EncounterUITests/RunnerUITests.swift
@@ -15,19 +15,7 @@
 
 import XCTest
 
-final class RunnerUITests: XCTestCase {
-
-  var app: XCUIApplication!
-
-  override func setUpWithError() throws {
-    continueAfterFailure = false
-    app = XCUIApplication()
-    app.launchArguments = ["-UITestResetState"]
-    app.launch()
-    XCTAssertTrue(
-      app.navigationBars["Party"].waitForExistence(timeout: 10),
-      "App should load and show Party screen within 10 seconds")
-  }
+final class RunnerUITests: EncounterUITestCase {
 
   // MARK: - Condition visibility in collapsed row
 
@@ -104,106 +92,4 @@ final class RunnerUITests: XCTestCase {
       "Stress button should still be visible after incrementing stress")
   }
 
-  // MARK: - Navigation helper
-
-  /// Navigates from the Party screen all the way into the live encounter runner.
-  ///
-  /// Flow:
-  ///   1. Add one player (required for "Run Encounter" to be enabled).
-  ///   2. Switch to Encounters tab.
-  ///   3. Create a new encounter.
-  ///   4. Open the encounter in the builder.
-  ///   5. Add one adversary from the compendium.
-  ///   6. Tap "Run Encounter".
-  private func navigateToRunner() {
-    // Step 1: Add one player.
-    app.buttons["party.add-player-button"].tap()
-    XCTAssertTrue(
-      app.textFields["party.form.name-field"].waitForExistence(timeout: 3),
-      "Player form should appear")
-    fillPlayerForm(
-      name: "Aric", hp: "6", stress: "6", evasion: "12",
-      major: "5", severe: "10", armor: "3")
-    app.buttons["party.form.commit-button"].tap()
-    XCTAssertTrue(
-      app.buttons.matching(identifier: "party.active-row").firstMatch
-        .waitForExistence(timeout: 5),
-      "Player should appear in active party")
-
-    // Step 2: Switch to Encounters.
-    let encountersTab = app.tabBars.buttons["Encounters"]
-    XCTAssertTrue(encountersTab.waitForExistence(timeout: 3))
-    encountersTab.tap()
-    XCTAssertTrue(
-      app.navigationBars["Encounters"].waitForExistence(timeout: 5),
-      "Encounters screen should appear")
-
-    // Step 3: Create encounter.
-    let createButton = app.buttons.matching(identifier: "library.create-button").firstMatch
-    XCTAssertTrue(createButton.waitForExistence(timeout: 3))
-    createButton.tap()
-    let createAlertButton = app.alerts["New Encounter"].buttons["Create"]
-    XCTAssertTrue(createAlertButton.waitForExistence(timeout: 3))
-    createAlertButton.tap()
-
-    // Step 4: Open the encounter in the builder.
-    let firstRow = app.buttons.matching(identifier: "library.row").firstMatch
-    XCTAssertTrue(firstRow.waitForExistence(timeout: 5))
-    firstRow.tap()
-
-    // Step 5: Add an adversary from the compendium.
-    let browseButton = app.buttons["builder.browse-compendium-button"]
-    XCTAssertTrue(
-      browseButton.waitForExistence(timeout: 5), "Browse Compendium button should be visible")
-    browseButton.tap()
-
-    // Wait for compendium list, then tap the first adversary row.
-    let firstAdversaryRow = app.buttons.matching(identifier: "compendium.adversary-row").firstMatch
-    XCTAssertTrue(
-      firstAdversaryRow.waitForExistence(timeout: 5),
-      "Compendium adversary list should appear")
-    firstAdversaryRow.tap()
-
-    // Tap "Add to Encounter" on the detail view.
-    let addButton = app.buttons["compendium.add-to-encounter-button"]
-    XCTAssertTrue(
-      addButton.waitForExistence(timeout: 5), "Add to Encounter button should be visible")
-    addButton.tap()
-
-    // Step 6: Run the encounter.
-    let runButton = app.buttons["builder.run-button"]
-    XCTAssertTrue(
-      runButton.waitForExistence(timeout: 5), "Run Encounter button should be visible and enabled")
-    XCTAssertTrue(
-      runButton.isEnabled,
-      "Run Encounter button should be enabled with one player and one adversary")
-    runButton.tap()
-
-    // Wait for the runner adversary list to appear.
-    XCTAssertTrue(
-      app.collectionViews["runner.adversary-list"].waitForExistence(timeout: 5),
-      "Runner adversary list should appear after tapping Run Encounter")
-  }
-
-  // MARK: - Form helper
-
-  private func fillPlayerForm(
-    name: String, hp: String, stress: String, evasion: String,
-    major: String, severe: String, armor: String
-  ) {
-    let fields: [(String, String)] = [
-      ("party.form.name-field", name),
-      ("party.form.max-hp-field", hp),
-      ("party.form.max-stress-field", stress),
-      ("party.form.evasion-field", evasion),
-      ("party.form.threshold-major-field", major),
-      ("party.form.threshold-severe-field", severe),
-      ("party.form.armor-slots-field", armor),
-    ]
-    for (id, value) in fields {
-      let field = app.textFields[id]
-      field.tap()
-      field.typeText(value)
-    }
-  }
 }