diff --git a/Assets/Scenes/Main Menu.unity b/Assets/Scenes/Main Menu.unity
index c1f111f09..4fafe8336 100644
--- a/Assets/Scenes/Main Menu.unity	
+++ b/Assets/Scenes/Main Menu.unity	
@@ -525,7 +525,7 @@ MonoBehaviour:
     type: 3}
   m_TrackedDeviceOrientationAction: {fileID: 1025543830046995696, guid: ca9f5fa95ffab41fb9a615ab714db018,
     type: 3}
-  m_DeselectOnBackgroundClick: 0
+  m_DeselectOnBackgroundClick: 1
   m_PointerBehavior: 0
 --- !u!114 &553528108
 MonoBehaviour:
diff --git a/Assets/Scripts/Editor/ScenarioPickerVerify.cs b/Assets/Scripts/Editor/ScenarioPickerVerify.cs
index 3d9acb75e..8d464f48e 100644
--- a/Assets/Scripts/Editor/ScenarioPickerVerify.cs
+++ b/Assets/Scripts/Editor/ScenarioPickerVerify.cs
@@ -51,6 +51,8 @@ public static class ScenarioPickerVerify
             CancelAndBackAreOnePath();
             DetailPaneFollowsSelection();
             OneGroupHasNoSectionLabel();
+            LaunchesOnceHoweverItIsReached();
+            ArrowingThroughTheRealListKeepsTheSelectionVisible();
             Debug.Log("[ScenarioPickerVerify] ok");
             EditorApplication.Exit(0);
         }
@@ -66,7 +68,7 @@ public static class ScenarioPickerVerify
         if (!condition) throw new InvalidOperationException(what);
     }
 
-    private static Screen Build(bool oneGroup = false)
+    private static Screen Build(bool oneGroup = false, bool real = false)
     {
         var (menu, list, detail) = ScenarioPickerCapture.Build();
         // Build opens the scene afresh, which destroys the previous EventSystem.
@@ -80,7 +82,7 @@ public static class ScenarioPickerVerify
             B = new Scenario[] { new Fake("Gamma", ambient: false) },
             C = new Scenario[] { new Fake("Delta"), new Fake("Echo") }
         };
-        var groups = oneGroup
+        var groups = real ? ScenarioPickerCapture.AllGroups() : oneGroup
             ? new List<(string label, Scenario[] scenarios)> { ("modes", screen.A) }
             : new List<(string label, Scenario[] scenarios)> { ("modes", screen.A), ("development", screen.B), ("test arenas", screen.C) };
         screen.Picker = ScenarioPicker.Show(list, detail, groups, screen.Launched.Add, () => screen.Backs++, menu.Dialog.Confirm);
@@ -88,9 +90,43 @@ public static class ScenarioPickerVerify
         screen.Rows = buttons.Take(buttons.Length - 1).ToArray();
         screen.Back = buttons.Last();
         screen.Launch = detail.GetComponentsInChildren<Button>(false).Single();
+        if (real) Layout(menu, list, detail);
         return screen;
     }
 
+    // A live 1920x1080 layout, as the game has one a frame after Show; edit mode has no frames, so it is forced here.
+    private static void Layout(MainMenu menu, PropertiesPanel list, PropertiesPanel detail)
+    {
+        menu.Dialog.gameObject.SetActive(false);
+        var canvas = menu.GetComponentInParent<Canvas>(true).rootCanvas;
+        var camera = new GameObject("verify camera").AddComponent<Camera>();
+        camera.targetTexture = new RenderTexture(1920, 1080, 24);
+        canvas.renderMode = RenderMode.ScreenSpaceCamera;
+        canvas.worldCamera = camera;
+        canvas.planeDistance = 10;
+        canvas.gameObject.SetActive(true);
+        Canvas.ForceUpdateCanvases();
+        LayoutRebuilder.ForceRebuildLayoutImmediate((RectTransform) canvas.transform);
+        foreach (var text in list.GetComponentsInChildren<TMP_Text>()) text.ForceMeshUpdate();
+        Canvas.ForceUpdateCanvases();
+        Scroll(list).onValueChanged.Invoke(Vector2.zero);
+    }
+
+    private static ScrollRect Scroll(PropertiesPanel list) => list.Content.GetComponentInParent<ScrollRect>();
+
+    // Wholly inside the viewport, in world space, and not hidden by FitViewport's CanvasGroup.
+    private static bool Shown(Button row, ScrollRect scroll)
+    {
+        var view = new Vector3[4];
+        ((RectTransform) scroll.viewport).GetWorldCorners(view);
+        var rect = new Vector3[4];
+        ((RectTransform) row.transform).GetWorldCorners(rect);
+        var alpha = 1f;
+        for (var t = row.transform; t != null && t != scroll.content; t = t.parent)
+            if (t.TryGetComponent<CanvasGroup>(out var group)) alpha = Mathf.Min(alpha, group.alpha);
+        return rect[0].y >= view[0].y - .01f && rect[1].y <= view[1].y + .01f && alpha == 1;
+    }
+
     private static void Move(Screen screen, MoveDirection direction) =>
         ExecuteEvents.Execute(screen.Launch.gameObject, new AxisEventData(EventSystem.current) { moveDir = direction }, ExecuteEvents.moveHandler);
 
@@ -190,4 +226,38 @@ public static class ScenarioPickerVerify
         Require(many.List.Children == 5 + 3 + 2 + 1, $"Three groups should list 5 rows, 3 section labels, 2 spacers and Back, not {many.List.Children} children.");
         Require(one.List.Children == 2 + 1, $"One group should list its 2 rows and Back, not {one.List.Children} children.");
     }
+
+    private static void LaunchesOnceHoweverItIsReached()
+    {
+        var screen = Build();
+        screen.Launch.onClick.Invoke();
+        screen.Launch.onClick.Invoke();
+        ExecuteEvents.Execute(screen.Launch.gameObject, new BaseEventData(EventSystem.current), ExecuteEvents.submitHandler);
+        Require(screen.Launched.Count == 1, $"Launch ran {screen.Launched.Count} times after a click, a second click and Submit.");
+        Require(screen.Launch.navigation.mode == Navigation.Mode.None && Scroll(screen.List).verticalScrollbar.navigation.mode == Navigation.Mode.None,
+            "The list scrollbar or Launch takes Unity navigation.");
+    }
+
+    // The real scenario groups overflow the list's viewport; every row the arrows reach must end wholly visible.
+    private static void ArrowingThroughTheRealListKeepsTheSelectionVisible()
+    {
+        var screen = Build(real: true);
+        var scroll = Scroll(screen.List);
+        var content = (RectTransform) scroll.content;
+        var viewport = (RectTransform) scroll.viewport;
+        Require(content.rect.height > viewport.rect.height + 1, $"The real list ({content.rect.height}) does not overflow its viewport ({viewport.rect.height}); the scroll rules are unmeasured.");
+        Require(Shown(screen.Rows[0], scroll), "The first row is not shown on Show.");
+        for (var i = 1; i < screen.Rows.Length; i++)
+        {
+            Move(screen, MoveDirection.Down);
+            Canvas.ForceUpdateCanvases();
+            Require(Shown(screen.Rows[i], scroll), $"Down to row {i} ({Selected(screen)}) left it hidden or cut off.");
+        }
+        for (var i = screen.Rows.Length - 2; i >= 0; i--)
+        {
+            Move(screen, MoveDirection.Up);
+            Canvas.ForceUpdateCanvases();
+            Require(Shown(screen.Rows[i], scroll), $"Up to row {i} ({Selected(screen)}) left it hidden or cut off.");
+        }
+    }
 }
diff --git a/Assets/Scripts/UI/ScenarioPicker.cs b/Assets/Scripts/UI/ScenarioPicker.cs
index 5b1bf1602..9d0c19464 100644
--- a/Assets/Scripts/UI/ScenarioPicker.cs
+++ b/Assets/Scripts/UI/ScenarioPicker.cs
@@ -6,6 +6,7 @@ using TMPro;
 using UnityEngine;
 using UnityEngine.Events;
 using UnityEngine.EventSystems;
+using UnityEngine.InputSystem.UI;
 using UnityEngine.UI;
 
 // The New Game screen: scenario names on the left pane by group, the selected scenario's brief, seed and ambient on a
@@ -28,6 +29,8 @@ public sealed class ScenarioPicker
     private UnityAction<Vector2> _fit;
     private static readonly Color Accent = new Color(1, .4458f, .05f);
     private int _selected;
+    private bool _launched;
+    private bool _restoreDeselect;
 
     private ScenarioPicker(PropertiesPanel list, PropertiesPanel detail, Action<Scenario> launch, Action back)
     {
@@ -112,6 +115,7 @@ public sealed class ScenarioPicker
         picker._launchButton.OnCancelAsObservable().Subscribe(_ => picker.Back());
 
         picker.StyleScrollbars();
+        picker.HoldFocus();
         picker.Select(0);
         // Layout is not live until the frame after Show; edit mode has no frames.
         if (Application.isPlaying) Observable.NextFrame().Subscribe(_ => picker.FitViewport());
@@ -165,6 +169,8 @@ public sealed class ScenarioPicker
         {
             if (!_scroll.verticalScrollbar.TryGetComponent<Image>(out var track)) track = _scroll.verticalScrollbar.gameObject.AddComponent<Image>();
             track.color = new Color(Accent.r, Accent.g, Accent.b, .2f);
+            // A click on the bar selects it and takes focus off Launch, which would silence the arrows.
+            _scroll.verticalScrollbar.navigation = new Navigation { mode = Navigation.Mode.None };
         }
         _scroll.onValueChanged.RemoveAllListeners();
         _fit = _ => FitViewport();
@@ -233,16 +239,21 @@ public sealed class ScenarioPicker
         if (scroll == null || scroll.content == null) return;
         var (low, high) = ViewSpan(scroll);
         var rowBounds = RectTransformUtility.CalculateRelativeRectTransformBounds(scroll.content, row);
-        var shift = rowBounds.max.y > high ? high - rowBounds.max.y
-            : rowBounds.min.y < low ? low - rowBounds.min.y : 0;
-        scroll.content.anchoredPosition -= new Vector2(0, shift);
+        var shift = rowBounds.max.y > high ? rowBounds.max.y - high
+            : rowBounds.min.y < low ? rowBounds.min.y - low : 0;
+        // Content moves against the row: a row above the viewport needs the content to move down, and the reverse.
+        scroll.content.anchoredPosition += new Vector2(0, shift);
         if (shift != 0) FitViewport();
     }
 
-    // Launches the selection; focus is cleared first so a repeated Enter or a second click cannot launch twice.
+    // Launches the selection, once: Enter, Submit and a mouse click all arrive here, and nothing launches again until
+    // the picker is shown afresh, however long the menu takes to fade out.
     private void Activate()
     {
+        if (_launched) return;
+        _launched = true;
         Focus(null);
+        ReleaseFocus();
         _launch(Selected);
     }
 
@@ -250,9 +261,26 @@ public sealed class ScenarioPicker
     private void Back()
     {
         Focus(null);
+        ReleaseFocus();
         _back();
     }
 
+    // While the picker is up, a click on empty space must not drop focus from Launch, or the arrows and Enter go dead.
+    // The input module's flag is scene-wide, so the picker takes it for its own lifetime and gives it back on leaving.
+    private void HoldFocus()
+    {
+        if (EventSystem.current == null || !(EventSystem.current.currentInputModule is InputSystemUIInputModule module) || !module.deselectOnBackgroundClick) return;
+        module.deselectOnBackgroundClick = false;
+        _restoreDeselect = true;
+    }
+
+    private void ReleaseFocus()
+    {
+        if (!_restoreDeselect) return;
+        _restoreDeselect = false;
+        if (EventSystem.current != null && EventSystem.current.currentInputModule is InputSystemUIInputModule module) module.deselectOnBackgroundClick = true;
+    }
+
     private static void Focus(GameObject target)
     {
         if (EventSystem.current != null) EventSystem.current.SetSelectedGameObject(target);