diff --git a/docs/phases/12-office/72-parent-meetings.md b/docs/phases/12-office/72-parent-meetings.md
index 87e50de..276664c 100644
--- a/docs/phases/12-office/72-parent-meetings.md
+++ b/docs/phases/12-office/72-parent-meetings.md
@@ -12,26 +12,26 @@
 
 ## Задачи
 
-- [ ] Только ИИ: редкий бросок от сида класса и дня; кнопки игрока нет
-- [ ] Условия: есть классный, рабочий день, после последнего урока **этого** класса, классный в
+- [x] Только ИИ: редкий бросок от сида класса и дня; кнопки игрока нет
+- [x] Условия: есть классный, рабочий день, после последнего урока **этого** класса, классный в
       школе; пороги в `BehaviorDef`
-- [ ] Классный остаётся в homeroom класса
-- [ ] Доля родителей класса приходит: получают узел (двор → путь → кабинет), обычная ходьба
-- [ ] Учитель-родитель ученика класса, уже в школе, может участвовать без второго инстанса
-- [ ] Собрание — ограниченное по времени действие/занятость узла; лёгкий сдвиг мнений
+- [x] Классный остаётся в homeroom класса
+- [x] Доля родителей класса приходит: получают узел (двор → путь → кабинет), обычная ходьба
+- [x] Учитель-родитель ученика класса, уже в школе, может участвовать без второго инстанса
+- [x] Собрание — ограниченное по времени действие/занятость узла; лёгкий сдвиг мнений
       семья↔классный
-- [ ] После — родители снова «вне школы»; классный свободен
-- [ ] `EventDef` info «собрание»; локали
-- [ ] Нет классного — собрание не планируется
+- [x] После — родители снова «вне школы»; классный свободен
+- [x] `EventDef` info «собрание»; локали
+- [x] Нет классного — собрание не планируется
 
 ## Тесты, без которых фаза не закрыта
 
-- [ ] Без `classTeacherId` собрание не стартует при том же сиде дня
-- [ ] С классным и прохождением редкости родители появляются на карте и уходят после
-- [ ] Собрание не раньше последнего урока класса
-- [ ] Тот же сид класса/дня → те же «кто пришёл» (детерминизм доли)
-- [ ] Игрок не назначает собрание по API
-- [ ] Skip ночи не оставляет родителей вечно в кабинете
+- [x] Без `classTeacherId` собрание не стартует при том же сиде дня
+- [x] С классным и прохождением редкости родители появляются на карте и уходят после
+- [x] Собрание не раньше последнего урока класса
+- [x] Тот же сид класса/дня → те же «кто пришёл» (детерминизм доли)
+- [x] Игрок не назначает собрание по API
+- [x] Skip ночи не оставляет родителей вечно в кабинете
 
 ## Критерий готовности
 
diff --git a/src/HSchool.Ai/ParentMeetings.cs b/src/HSchool.Ai/ParentMeetings.cs
new file mode 100644
index 0000000..1be87be
--- /dev/null
+++ b/src/HSchool.Ai/ParentMeetings.cs
@@ -0,0 +1,129 @@
+using HSchool.Content;
+using HSchool.People;
+using HSchool.Schedule;
+
+namespace HSchool.Ai;
+
+/// <summary>
+/// Pure helpers for AI class-teacher parent meetings. Session state lives on the school worker.
+/// </summary>
+public static class ParentMeetings
+{
+    public const string MeetingAction = "ParentMeeting";
+
+    /// <summary>Presence / card label while walking to the homeroom. Not a planner pick.</summary>
+    public const string GoingAction = "GoingToParentMeeting";
+
+    public static DateTime? LastLessonEnd(
+        DefCatalog catalog,
+        Timetable? timetable,
+        SchoolClass schoolClass,
+        DateTime time)
+    {
+        ArgumentNullException.ThrowIfNull(catalog);
+        ArgumentNullException.ThrowIfNull(schoolClass);
+        if (catalog.DayFrame is null || timetable is null)
+        {
+            return null;
+        }
+
+        var weekday = SchoolDay.WeekdayIndex(time);
+        var lastPeriod = timetable.Lessons
+            .Where(lesson =>
+                lesson.ClassId.Equals(schoolClass.Id, StringComparison.Ordinal)
+                && lesson.Day == weekday)
+            .Select(lesson => lesson.Period)
+            .DefaultIfEmpty(0)
+            .Max();
+        if (lastPeriod < 1)
+        {
+            return null;
+        }
+
+        var end = SchoolDay.PeriodEnd(catalog.DayFrame, lastPeriod);
+        var day = DateTime.SpecifyKind(time, DateTimeKind.Utc).Date;
+        return day + end.ToTimeSpan();
+    }
+
+    public static bool IsAfterLastLesson(
+        DefCatalog catalog,
+        Timetable? timetable,
+        SchoolClass schoolClass,
+        DateTime time,
+        int weekDays)
+    {
+        if (!SchoolDay.IsWorkday(catalog, time, weekDays))
+        {
+            return false;
+        }
+
+        var end = LastLessonEnd(catalog, timetable, schoolClass, time);
+        if (end is null)
+        {
+            return false;
+        }
+
+        return DateTime.SpecifyKind(time, DateTimeKind.Utc) >= end.Value;
+    }
+
+    public static bool RollMeeting(float chance, int seed) =>
+        chance >= 1f || (chance > 0f && TalkCircles.Roll01(seed) < chance);
+
+    /// <summary>
+    /// Unique parents of the class pupils, ordinal order. Teacher-parents stay in the list — one
+    /// roster id, no second instance.
+    /// </summary>
+    public static IReadOnlyList<string> ClassParentIds(Roster roster, SchoolClass schoolClass)
+    {
+        ArgumentNullException.ThrowIfNull(roster);
+        ArgumentNullException.ThrowIfNull(schoolClass);
+
+        var pupilSet = schoolClass.PupilIds.ToHashSet(StringComparer.Ordinal);
+        var parents = new HashSet<string>(StringComparer.Ordinal);
+        foreach (var family in roster.Families)
+        {
+            if (!family.ChildIds.Any(childId => pupilSet.Contains(childId)))
+            {
+                continue;
+            }
+
+            foreach (var parentId in family.ParentIds)
+            {
+                parents.Add(parentId);
+            }
+        }
+
+        return parents.OrderBy(id => id, StringComparer.Ordinal).ToArray();
+    }
+
+    public static IReadOnlyList<string> SelectAttendees(
+        Roster roster,
+        SchoolClass schoolClass,
+        float fraction,
+        int schoolSeed,
+        int dayNumber)
+    {
+        var parents = ClassParentIds(roster, schoolClass);
+        if (parents.Count == 0 || fraction <= 0f)
+        {
+            return [];
+        }
+
+        if (fraction >= 1f)
+        {
+            return parents;
+        }
+
+        var chosen = new List<string>();
+        foreach (var parentId in parents)
+        {
+            var seed = Seed.Mix(schoolSeed, parentId, dayNumber, Seed.MeetingAttendSalt);
+            if (TalkCircles.Roll01(seed) < fraction)
+            {
+                chosen.Add(parentId);
+            }
+        }
+
+        return chosen;
+    }
+}
diff --git a/src/HSchool.Client/src/i18n/strings.ts b/src/HSchool.Client/src/i18n/strings.ts
index cc2df11..352e8d1 100644
--- a/src/HSchool.Client/src/i18n/strings.ts
+++ b/src/HSchool.Client/src/i18n/strings.ts
@@ -402,6 +402,7 @@ const ru = {
   LessonStarted: 'Начало урока',
   GenerationFailed: 'Не удалось нарисовать портрет',
   DirectorSummoned: 'Ученика вызвали к директору',
+  ParentMeeting: 'Идёт родительское собрание',
   noticeDismiss: 'Закрыть',
   noticeGenerateImage: 'Создать картинку',
   noticeGenerateImageBusy: 'Рисуем…',
@@ -812,6 +813,7 @@ const en: Messages = {
   LessonStarted: 'A lesson has started',
   GenerationFailed: 'Portrait generation failed',
   DirectorSummoned: 'A pupil was summoned to the principal',
+  ParentMeeting: 'A parent meeting is under way',
   noticeDismiss: 'Close',
   noticeGenerateImage: 'Create image',
   noticeGenerateImageBusy: 'Drawing…',
diff --git a/src/HSchool.Client/src/ui/noticeToasts.ts b/src/HSchool.Client/src/ui/noticeToasts.ts
index 1353c86..53a7502 100644
--- a/src/HSchool.Client/src/ui/noticeToasts.ts
+++ b/src/HSchool.Client/src/ui/noticeToasts.ts
@@ -10,6 +10,7 @@ export function noticeLabel(defName: string): string {
     case 'LessonStarted':
     case 'GenerationFailed':
     case 'DirectorSummoned':
+    case 'ParentMeeting':
       return t(defName satisfies MessageKey);
     default:
       return defName;
diff --git a/src/HSchool.Content/EventDefValidator.cs b/src/HSchool.Content/EventDefValidator.cs
index 44da79b..5c4b3e7 100644
--- a/src/HSchool.Content/EventDefValidator.cs
+++ b/src/HSchool.Content/EventDefValidator.cs
@@ -15,6 +15,7 @@ internal static class EventDefValidator
         EventTriggers.LessonStart,
         EventTriggers.GenerationFailed,
         EventTriggers.DirectorSummon,
+        EventTriggers.ParentMeeting,
     };
 
     private static readonly HashSet<string> Actions = new(StringComparer.Ordinal)
diff --git a/src/HSchool.Content/EventDefs.cs b/src/HSchool.Content/EventDefs.cs
index d21f653..a011bee 100644
--- a/src/HSchool.Content/EventDefs.cs
+++ b/src/HSchool.Content/EventDefs.cs
@@ -13,6 +13,7 @@ public static class EventTriggers
     public const string LessonStart = "lessonStart";
     public const string GenerationFailed = "generationFailed";
     public const string DirectorSummon = "directorSummon";
+    public const string ParentMeeting = "parentMeeting";
 }
 
 public static class EventActions
diff --git a/src/HSchool.Content/PeopleDefValidator.cs b/src/HSchool.Content/PeopleDefValidator.cs
index ffdcb28..ca4277c 100644
--- a/src/HSchool.Content/PeopleDefValidator.cs
+++ b/src/HSchool.Content/PeopleDefValidator.cs
@@ -684,6 +684,24 @@ internal static class PeopleDefValidator
                 $"BehaviorDef '{behavior.DefName}' directorHearingMinutes must be positive.");
         }
 
+        if (behavior.ParentMeetingChance is < 0f or > 1f)
+        {
+            throw new ContentLoadException(
+                $"BehaviorDef '{behavior.DefName}' parentMeetingChance must be 0–1.");
+        }
+
+        if (behavior.ParentMeetingAttendanceFraction is < 0f or > 1f)
+        {
+            throw new ContentLoadException(
+                $"BehaviorDef '{behavior.DefName}' parentMeetingAttendanceFraction must be 0–1.");
+        }
+
+        if (behavior.ParentMeetingMinutes <= 0f)
+        {
+            throw new ContentLoadException(
+                $"BehaviorDef '{behavior.DefName}' parentMeetingMinutes must be positive.");
+        }
+
         if (behavior.LessonMarkMax < 0)
         {
             throw new ContentLoadException($"BehaviorDef '{behavior.DefName}' lessonMarkMax cannot be negative.");
diff --git a/src/HSchool.Content/PeopleDefs.cs b/src/HSchool.Content/PeopleDefs.cs
index 29fa813..953f0fb 100644
--- a/src/HSchool.Content/PeopleDefs.cs
+++ b/src/HSchool.Content/PeopleDefs.cs
@@ -595,6 +595,25 @@ public sealed class BehaviorDef : Def
     /// <summary>Opinion of the Principal after a hearing. Negative — the visit is not praise.</summary>
     public int DirectorHearingOpinionShift { get; init; } = -12;
 
+    /// <summary>
+    /// Chance a class with a class teacher holds a parent meeting after its last lesson.
+    /// Low in vanilla — meetings are rare AI, not a weekly calendar.
+    /// </summary>
+    public float ParentMeetingChance { get; init; } = 0.08f;
+
+    /// <summary>
+    /// Independent chance each class parent is invited when a meeting starts. Not 100% attendance.
+    /// </summary>
+    public float ParentMeetingAttendanceFraction { get; init; } = 0.4f;
+
+    /// <summary>Game minutes the class teacher keeps the homeroom for the meeting.</summary>
+    public float ParentMeetingMinutes { get; init; } = 20f;
+
+    /// <summary>
+    /// Opinion shift both ways between each attending parent and the class teacher. Small and positive.
+    /// </summary>
+    public int ParentMeetingOpinionShift { get; init; } = 3;
+
     public static IReadOnlyList<string> DefaultOffenseMemoryKinds { get; } =
     [
         "quarrel",
diff --git a/src/HSchool.People/Seed.cs b/src/HSchool.People/Seed.cs
index 306b8f9..7b0d97e 100644
--- a/src/HSchool.People/Seed.cs
+++ b/src/HSchool.People/Seed.cs
@@ -23,6 +23,8 @@ public static class Seed
     public const int HomeSalt = 15;
     public const int SummonSalt = 16;
     public const int HealthSalt = 17;
+    public const int MeetingSalt = 18;
+    public const int MeetingAttendSalt = 19;
 
     /// <summary>A stream that belongs to the school rather than to one family.</summary>
     public static int ForSchool(int schoolSeed, int salt) => Mix(schoolSeed, familyIndex: -1, salt);
diff --git a/src/HSchool.Server/Game/PersonCardReader.cs b/src/HSchool.Server/Game/PersonCardReader.cs
index 841a966..b06f66e 100644
--- a/src/HSchool.Server/Game/PersonCardReader.cs
+++ b/src/HSchool.Server/Game/PersonCardReader.cs
@@ -62,7 +62,8 @@ internal static partial class PersonCardReader
         var needs = LiveNeeds(school.World, personId) ?? person.Needs;
         var skills = LiveSkills(school.World, personId);
         var activityId = LiveActivity(school.World, personId)
-            ?? school.DirectorSummonPresenceActionId(personId);
+            ?? school.DirectorSummonPresenceActionId(personId)
+            ?? school.ParentMeetingPresenceActionId(personId);
         string? activityLabel = null;
         if (activityId is not null && catalog is not null && catalog.Actions.TryGetValue(activityId, out var action))
         {
diff --git a/src/HSchool.Server/mods/core/defs/actions/living.jsonc b/src/HSchool.Server/mods/core/defs/actions/living.jsonc
index 74a27a0..b289c45 100644
--- a/src/HSchool.Server/mods/core/defs/actions/living.jsonc
+++ b/src/HSchool.Server/mods/core/defs/actions/living.jsonc
@@ -155,6 +155,22 @@
     "roles": ["student"],
     "weight": 0,
   },
+  {
+    // Class-teacher parent meeting (slice 12 phase 72). Weight 0 — planner never picks it;
+    // ParentMeetingSystem starts it when the teacher is idle in the homeroom.
+    "defName": "ParentMeeting",
+    "room": "Classroom",
+    "minutes": 20,
+    "roles": ["staff"],
+    "weight": 0,
+  },
+  {
+    "defName": "GoingToParentMeeting",
+    "room": "Classroom",
+    "minutes": 1,
+    "roles": ["staff", "parent"],
+    "weight": 0,
+  },
   {
     "defName": "ChangeClothesMale",
     "room": "MaleChangingRoom",
diff --git a/src/HSchool.Server/mods/core/defs/behavior/rules.jsonc b/src/HSchool.Server/mods/core/defs/behavior/rules.jsonc
index 4874084..fc67ee3 100644
--- a/src/HSchool.Server/mods/core/defs/behavior/rules.jsonc
+++ b/src/HSchool.Server/mods/core/defs/behavior/rules.jsonc
@@ -104,6 +104,11 @@
     "directorSummonReprimandChance": 0.35,
     "directorHearingMinutes": 5,
     "directorHearingOpinionShift": -12,
+    // Parent meetings (slice 12 phase 72). Rare AI after the class's last lesson.
+    "parentMeetingChance": 0.08,
+    "parentMeetingAttendanceFraction": 0.4,
+    "parentMeetingMinutes": 20,
+    "parentMeetingOpinionShift": 3,
     // Lesson marks 2–5 from lesson quality (slice 13 phase 73). One mark per slot.
     "lessonMarkMax": 40,
     // Inclusive quality floors for 5, 4, 3 (descending). Below the last → 2.
diff --git a/src/HSchool.Server/mods/core/defs/events/notices.jsonc b/src/HSchool.Server/mods/core/defs/events/notices.jsonc
index 3139ba0..ac1d731 100644
--- a/src/HSchool.Server/mods/core/defs/events/notices.jsonc
+++ b/src/HSchool.Server/mods/core/defs/events/notices.jsonc
@@ -31,4 +31,12 @@
     "trigger": "directorSummon",
     "action": "none",
   },
+  {
+    "defName": "ParentMeeting",
+    "severity": "info",
+    "pause": false,
+    "ttlMs": 8000,
+    "trigger": "parentMeeting",
+    "action": "none",
+  },
 ]
diff --git a/src/HSchool.Server/mods/core/localizations/en.jsonc b/src/HSchool.Server/mods/core/localizations/en.jsonc
index a5df004..7910552 100644
--- a/src/HSchool.Server/mods/core/localizations/en.jsonc
+++ b/src/HSchool.Server/mods/core/localizations/en.jsonc
@@ -232,7 +232,9 @@
   "LessonStarted": "A lesson has started",
   "GenerationFailed": "Portrait generation failed",
   "DirectorSummoned": "A pupil was summoned to the principal",
+  "ParentMeeting": "A parent meeting is under way",
   "GoingToPrincipal": "going to the principal",
   "WaitForPrincipal": "waiting at the principal's office",
+  "GoingToParentMeeting": "going to a parent meeting",
   "core": "Core",
 }
diff --git a/src/HSchool.Server/mods/core/localizations/ru.jsonc b/src/HSchool.Server/mods/core/localizations/ru.jsonc
index 36bb33b..a2f673d 100644
--- a/src/HSchool.Server/mods/core/localizations/ru.jsonc
+++ b/src/HSchool.Server/mods/core/localizations/ru.jsonc
@@ -232,7 +232,9 @@
   "LessonStarted": "Начало урока",
   "GenerationFailed": "Не удалось нарисовать портрет",
   "DirectorSummoned": "Ученика вызвали к директору",
+  "ParentMeeting": "Идёт родительское собрание",
   "GoingToPrincipal": "идёт к директору",
   "WaitForPrincipal": "ждёт у кабинета директора",
+  "GoingToParentMeeting": "идёт на собрание",
   "core": "Базовая игра",
 }
diff --git a/src/HSchool.Simulation/ActivitySystem.cs b/src/HSchool.Simulation/ActivitySystem.cs
index a135e13..4886756 100644
--- a/src/HSchool.Simulation/ActivitySystem.cs
+++ b/src/HSchool.Simulation/ActivitySystem.cs
@@ -158,6 +158,11 @@ internal static class ActivitySystem
                 DirectorSummonSystem.CompleteHearing(school, identity.Id);
             }
 
+            if (IsParentMeeting(action.DefName))
+            {
+                ParentMeetingSystem.CompleteMeeting(school, identity.Id);
+            }
+
             activity = PersonActivity.Idle;
             completed.Add(identity.Id);
         });
@@ -190,6 +195,10 @@ internal static class ActivitySystem
         actionId is not null
         && actionId.Equals(DirectorSummons.HearingAction, StringComparison.Ordinal);
 
+    internal static bool IsParentMeeting(string? actionId) =>
+        actionId is not null
+        && actionId.Equals(ParentMeetings.MeetingAction, StringComparison.Ordinal);
+
     private static int Occupied(School school, string nodeId, string thing)
     {
         var occupied = 0;
diff --git a/src/HSchool.Simulation/ParentMeetingSystem.cs b/src/HSchool.Simulation/ParentMeetingSystem.cs
new file mode 100644
index 0000000..0b94807
--- /dev/null
+++ b/src/HSchool.Simulation/ParentMeetingSystem.cs
@@ -0,0 +1,451 @@
+using Arch.Core;
+using HSchool.Ai;
+using HSchool.Content;
+using HSchool.People;
+
+namespace HSchool.Simulation;
+
+/// <summary>
+/// Rare AI parent meetings after a class's last lesson. Only the school worker mutates
+/// <see cref="School.ActiveParentMeetings"/>.
+/// </summary>
+internal static class ParentMeetingSystem
+{
+    private static readonly QueryDescription PresenceQuery =
+        new QueryDescription().WithAll<PersonIdentity, Presence, PersonActivity, Intent>();
+
+    public static bool IsInMeeting(School school, string personId) =>
+        school.ActiveParentMeetings.Any(session =>
+            session.TeacherId.Equals(personId, StringComparison.Ordinal)
+            || session.AttendeeIds.Contains(personId));
+
+    public static bool TryDutyRoom(School school, string personId, out string roomId)
+    {
+        roomId = null!;
+        var session = school.ActiveParentMeetings.FirstOrDefault(row =>
+            row.TeacherId.Equals(personId, StringComparison.Ordinal)
+            || row.AttendeeIds.Contains(personId));
+        if (session is null)
+        {
+            return false;
+        }
+
+        roomId = session.HomeroomId;
+        return true;
+    }
+
+    public static void Apply(School school)
+    {
+        if (school.Roster is null || school.Map is null || school.Catalog is null)
+        {
+            return;
+        }
+
+        TryStartMeetings(school);
+        foreach (var session in school.ActiveParentMeetings.ToArray())
+        {
+            TryStartMeetingAction(school, session);
+        }
+    }
+
+    /// <summary>
+    /// Start a meeting for one class when rarity and attendance pass. Used by tests with chance 1.
+    /// </summary>
+    public static bool TryStart(
+        School school,
+        string classId,
+        float chance,
+        float fraction)
+    {
+        if (school.Roster is null || school.Catalog is null)
+        {
+            return false;
+        }
+
+        var schoolClass = school.Roster.Classes.FirstOrDefault(row =>
+            row.Id.Equals(classId, StringComparison.Ordinal));
+        if (schoolClass?.ClassTeacherId is null
+            || string.IsNullOrWhiteSpace(schoolClass.RoomId))
+        {
+            return false;
+        }
+
+        if (school.ActiveParentMeetings.Any(row =>
+                row.ClassId.Equals(classId, StringComparison.Ordinal)))
+        {
+            return false;
+        }
+
+        if (!ParentMeetings.IsAfterLastLesson(
+                school.Catalog,
+                school.Timetable,
+                schoolClass,
+                school.Clock.Time,
+                school.SchoolWeekDays))
+        {
+            return false;
+        }
+
+        if (!IsOnCampus(school, schoolClass.ClassTeacherId))
+        {
+            return false;
+        }
+
+        var dayNumber = DateOnly.FromDateTime(school.Clock.Time).DayNumber;
+        school.ParentMeetingRolledToday.Add(schoolClass.Id);
+        var seed = Seed.Mix(school.PeopleSeed, schoolClass.Id, dayNumber, Seed.MeetingSalt);
+        if (!ParentMeetings.RollMeeting(chance, seed))
+        {
+            return false;
+        }
+
+        var attendees = ParentMeetings.SelectAttendees(
+            school.Roster,
+            schoolClass,
+            fraction,
+            school.PeopleSeed,
+            dayNumber);
+        if (attendees.Count == 0)
+        {
+            return false;
+        }
+
+        BeginSession(school, schoolClass, attendees);
+        return true;
+    }
+
+    public static void ClearAll(School school)
+    {
+        school.ParentMeetingRolledToday.Clear();
+        if (school.ActiveParentMeetings.Count == 0)
+        {
+            return;
+        }
+
+        var ids = school.ActiveParentMeetings
+            .SelectMany(session => session.AttendeeIds.Append(session.TeacherId))
+            .Distinct(StringComparer.Ordinal)
+            .ToArray();
+        school.ActiveParentMeetings.Clear();
+        foreach (var id in ids)
+        {
+            ForceOffCampusIfParentOnly(school, id);
+            PresenceSystem.Enqueue(school, id);
+        }
+    }
+
+    public static void CompleteMeeting(School school, string teacherId)
+    {
+        var session = school.ActiveParentMeetings.FirstOrDefault(row =>
+            row.TeacherId.Equals(teacherId, StringComparison.Ordinal) && row.InProgress);
+        if (session is null)
+        {
+            return;
+        }
+
+        ApplyOpinionShifts(school, session);
+        school.ActiveParentMeetings.Remove(session);
+        foreach (var parentId in session.AttendeeIds)
+        {
+            SendHome(school, parentId);
+            PresenceSystem.Enqueue(school, parentId);
+        }
+
+        PresenceSystem.Enqueue(school, session.TeacherId);
+    }
+
+    private static void TryStartMeetings(School school)
+    {
+        var roster = school.Roster!;
+        var catalog = school.Catalog!;
+        var rules = catalog.BehaviorRules;
+        var chance = rules?.ParentMeetingChance ?? 0.08f;
+        var fraction = rules?.ParentMeetingAttendanceFraction ?? 0.4f;
+        var dayNumber = DateOnly.FromDateTime(school.Clock.Time).DayNumber;
+
+        foreach (var schoolClass in roster.Classes.OrderBy(row => row.Id, StringComparer.Ordinal))
+        {
+            if (schoolClass.ClassTeacherId is null
+                || string.IsNullOrWhiteSpace(schoolClass.RoomId))
+            {
+                continue;
+            }
+
+            if (school.ParentMeetingRolledToday.Contains(schoolClass.Id)
+                || school.ActiveParentMeetings.Any(row =>
+                    row.ClassId.Equals(schoolClass.Id, StringComparison.Ordinal)))
+            {
+                continue;
+            }
+
+            if (!ParentMeetings.IsAfterLastLesson(
+                    catalog,
+                    school.Timetable,
+                    schoolClass,
+                    school.Clock.Time,
+                    school.SchoolWeekDays))
+            {
+                continue;
+            }
+
+            if (!IsOnCampus(school, schoolClass.ClassTeacherId))
+            {
+                continue;
+            }
+
+            school.ParentMeetingRolledToday.Add(schoolClass.Id);
+            var seed = Seed.Mix(school.PeopleSeed, schoolClass.Id, dayNumber, Seed.MeetingSalt);
+            if (!ParentMeetings.RollMeeting(chance, seed))
+            {
+                continue;
+            }
+
+            var attendees = ParentMeetings.SelectAttendees(
+                roster,
+                schoolClass,
+                fraction,
+                school.PeopleSeed,
+                dayNumber);
+            if (attendees.Count == 0)
+            {
+                continue;
+            }
+
+            BeginSession(school, schoolClass, attendees);
+        }
+    }
+
+    private static void BeginSession(
+        School school,
+        SchoolClass schoolClass,
+        IReadOnlyList<string> attendees)
+    {
+        var session = new ParentMeetingSession(
+            schoolClass.Id,
+            schoolClass.ClassTeacherId!,
+            schoolClass.RoomId,
+            attendees);
+        school.ActiveParentMeetings.Add(session);
+        PresenceSystem.Enqueue(school, session.TeacherId);
+        foreach (var parentId in attendees)
+        {
+            PresenceSystem.Enqueue(school, parentId);
+        }
+
+        school.RaiseWorldEvent(new WorldEvent(EventTriggers.ParentMeeting, session.TeacherId));
+    }
+
+    private static void TryStartMeetingAction(School school, ParentMeetingSession session)
+    {
+        if (session.InProgress || school.Catalog is null)
+        {
+            return;
+        }
+
+        if (!IsIdleInRoom(school, session.TeacherId, session.HomeroomId))
+        {
+            return;
+        }
+
+        // At least one invited parent present and idle — teacher-parents already on campus count.
+        var anyParentHere = session.AttendeeIds.Any(id => IsIdleInRoom(school, id, session.HomeroomId));
+        if (!anyParentHere)
+        {
+            return;
+        }
+
+        if (!school.Catalog.Actions.TryGetValue(ParentMeetings.MeetingAction, out var action)
+            || action.Abstract)
+        {
+            return;
+        }
+
+        var minutes = school.Catalog.BehaviorRules?.ParentMeetingMinutes ?? action.Minutes;
+        if (minutes <= 0f)
+        {
+            minutes = action.Minutes;
+        }
+
+        var started = false;
+        school.World.Query(
+            in PresenceQuery,
+            (ref PersonIdentity identity, ref Presence presence, ref PersonActivity activity, ref Intent intent) =>
+            {
+                if (started || !identity.Id.Equals(session.TeacherId, StringComparison.Ordinal))
+                {
+                    return;
+                }
+
+                if (activity.IsActive)
+                {
+                    return;
+                }
+
+                activity = new PersonActivity(ParentMeetings.MeetingAction, null, minutes);
+                intent = Intent.None;
+                session.InProgress = true;
+                started = true;
+            });
+    }
+
+    private static void ApplyOpinionShifts(School school, ParentMeetingSession session)
+    {
+        var roster = school.Roster!;
+        var rules = school.Catalog?.BehaviorRules;
+        if (rules is null)
+        {
+            return;
+        }
+
+        var shift = rules.ParentMeetingOpinionShift;
+        if (shift == 0)
+        {
+            return;
+        }
+
+        var teacher = roster.People.FirstOrDefault(row =>
+            row.Id.Equals(session.TeacherId, StringComparison.Ordinal));
+        if (teacher is null)
+        {
+            return;
+        }
+
+        foreach (var parentId in session.AttendeeIds.OrderBy(id => id, StringComparer.Ordinal))
+        {
+            var parent = roster.People.FirstOrDefault(row =>
+                row.Id.Equals(parentId, StringComparison.Ordinal));
+            if (parent is null)
+            {
+                continue;
+            }
+
+            var parentOfTeacher = OpinionStore.Get(parent, session.TeacherId) ?? 0;
+            OpinionStore.Set(parent, session.TeacherId, parentOfTeacher + shift);
+            var teacherOfParent = OpinionStore.Get(teacher, parentId) ?? 0;
+            OpinionStore.Set(teacher, parentId, teacherOfParent + shift);
+        }
+
+        school.RosterTalkDirty = true;
+    }
+
+    private static void SendHome(School school, string personId)
+    {
+        if (school.Walks is null)
+        {
+            ForceOffCampusIfParentOnly(school, personId);
+            return;
+        }
+
+        var person = school.Roster?.People.FirstOrDefault(row =>
+            row.Id.Equals(personId, StringComparison.Ordinal));
+        // Staff who are also parents stay for the rest of their work day.
+        if (person is { IsStaff: true })
+        {
+            return;
+        }
+
+        school.World.Query(
+            in PresenceQuery,
+            (ref PersonIdentity identity, ref Presence presence, ref PersonActivity activity, ref Intent intent) =>
+            {
+                if (!identity.Id.Equals(personId, StringComparison.Ordinal))
+                {
+                    return;
+                }
+
+                activity = PersonActivity.Idle;
+                intent = Intent.None;
+                if (!presence.IsOnCampus)
+                {
+                    presence = Presence.OffCampus;
+                    return;
+                }
+
+                presence = PresenceStepper.StartWalk(
+                    presence,
+                    school.Walks,
+                    school.Walks.TerritoryId,
+                    headingHome: true);
+            });
+    }
+
+    private static void ForceOffCampusIfParentOnly(School school, string personId)
+    {
+        var person = school.Roster?.People.FirstOrDefault(row =>
+            row.Id.Equals(personId, StringComparison.Ordinal));
+        if (person is { IsStaff: true } || person is { IsStudent: true })
+        {
+            return;
+        }
+
+        school.World.Query(
+            in PresenceQuery,
+            (ref PersonIdentity identity, ref Presence presence, ref PersonActivity activity, ref Intent intent) =>
+            {
+                if (!identity.Id.Equals(personId, StringComparison.Ordinal))
+                {
+                    return;
+                }
+
+                presence = Presence.OffCampus;
+                activity = PersonActivity.Idle;
+                intent = Intent.None;
+            });
+    }
+
+    private static bool IsOnCampus(School school, string personId)
+    {
+        var onCampus = false;
+        school.World.Query(
+            in PresenceQuery,
+            (ref PersonIdentity identity, ref Presence presence, ref PersonActivity _, ref Intent _) =>
+            {
+                if (identity.Id.Equals(personId, StringComparison.Ordinal))
+                {
+                    onCampus = presence.IsOnCampus;
+                }
+            });
+        return onCampus;
+    }
+
+    private static bool IsIdleInRoom(School school, string personId, string roomId)
+    {
+        var found = false;
+        school.World.Query(
+            in PresenceQuery,
+            (ref PersonIdentity identity, ref Presence presence, ref PersonActivity activity, ref Intent _) =>
+            {
+                if (!identity.Id.Equals(personId, StringComparison.Ordinal))
+                {
+                    return;
+                }
+
+                var walking = presence.Path.Length > 0 || presence.RemainingMinutes > 0
+                    || (presence.DestinationId is not null
+                        && !presence.DestinationId.Equals(presence.NodeId, StringComparison.Ordinal));
+                found = !activity.IsActive
+                    && !walking
+                    && presence.NodeId is not null
+                    && presence.NodeId.Equals(roomId, StringComparison.Ordinal);
+            });
+        return found;
+    }
+}
+
+/// <summary>One active parent meeting for a class.</summary>
+internal sealed class ParentMeetingSession(
+    string classId,
+    string teacherId,
+    string homeroomId,
+    IReadOnlyList<string> attendeeIds)
+{
+    public string ClassId { get; } = classId;
+
+    public string TeacherId { get; } = teacherId;
+
+    public string HomeroomId { get; } = homeroomId;
+
+    public IReadOnlyList<string> AttendeeIds { get; } = attendeeIds;
+
+    public bool InProgress { get; set; }
+}
diff --git a/src/HSchool.Simulation/PresenceSystem.cs b/src/HSchool.Simulation/PresenceSystem.cs
index 864328c..1a2661d 100644
--- a/src/HSchool.Simulation/PresenceSystem.cs
+++ b/src/HSchool.Simulation/PresenceSystem.cs
@@ -331,7 +331,8 @@ internal static class PresenceSystem
         var bound = Duty.IsOtherStaff(person)
             ? slot.Kind != DaySlotKind.Outside
             : slot.Kind == DaySlotKind.Lesson && lessons.Any(lesson => lesson.Period == slot.Index);
-        if (DirectorSummonSystem.IsSummoned(school, person.Id))
+        if (DirectorSummonSystem.IsSummoned(school, person.Id)
+            || ParentMeetingSystem.IsInMeeting(school, person.Id))
         {
             bound = true;
         }
@@ -352,9 +353,24 @@ internal static class PresenceSystem
             return null;
         }
 
+        if (activity.IsActive && ActivitySystem.IsParentMeeting(activity.ActionId))
+        {
+            return null;
+        }
+
         if (!presence.IsOnCampus)
         {
             intent = Intent.None;
+            if (ParentMeetingSystem.TryDutyRoom(school, person.Id, out var meetingArrive))
+            {
+                presence = PresenceStepper.StartWalk(
+                    Presence.OffCampus,
+                    walks,
+                    meetingArrive,
+                    headingHome: false);
+                return null;
+            }
+
             if (plan.AppearAt is { } appear && now >= appear && (plan.WalkHomeAt is null || now < plan.WalkHomeAt))
             {
                 var dest = plan.FirstRoom ?? Duty.RoomAt(
@@ -379,7 +395,10 @@ internal static class PresenceSystem
             return null;
         }
 
-        if (plan.WalkHomeAt is { } leave && now >= leave && !DirectorSummonSystem.IsSummoned(school, person.Id))
+        if (plan.WalkHomeAt is { } leave
+            && now >= leave
+            && !DirectorSummonSystem.IsSummoned(school, person.Id)
+            && !ParentMeetingSystem.IsInMeeting(school, person.Id))
         {
             activity = PersonActivity.Idle;
             intent = Intent.None;
@@ -399,6 +418,11 @@ internal static class PresenceSystem
             duty = summonRoom;
             bound = true;
         }
+        else if (ParentMeetingSystem.TryDutyRoom(school, person.Id, out var meetingRoom))
+        {
+            duty = meetingRoom;
+            bound = true;
+        }
 
         if (duty is null)
         {
diff --git a/src/HSchool.Simulation/School.cs b/src/HSchool.Simulation/School.cs
index 6096437..c5fc3d6 100644
--- a/src/HSchool.Simulation/School.cs
+++ b/src/HSchool.Simulation/School.cs
@@ -153,6 +153,14 @@ public sealed class School : IDisposable
 
     internal int NextSummonOrder { get; set; }
 
+    /// <summary>
+    /// Active parent meetings. Worker thread only — never HTTP. Cleared on morning / skip.
+    /// </summary>
+    internal List<ParentMeetingSession> ActiveParentMeetings { get; } = [];
+
+    /// <summary>Class ids that already rolled a meeting chance today (pass or fail).</summary>
+    internal HashSet<string> ParentMeetingRolledToday { get; } = new(StringComparer.Ordinal);
+
     /// <summary>
     /// A finished or interrupted circle wrote opinions onto the roster. <see cref="Tick"/>
     /// returns this so the worker persists <c>people.json</c> — same seam as morning dress.
@@ -314,6 +322,7 @@ public sealed class School : IDisposable
         Clock.JumpTo(next.Value);
         TalkCircleSystem.AbandonAll(this);
         DirectorSummonSystem.ClearAll(this);
+        ParentMeetingSystem.ClearAll(this);
         ResetDayLog();
         var peopleChanged = TryYearlyIntake(before, next.Value);
         peopleChanged |= TryApplicantRefresh();
@@ -388,6 +397,7 @@ public sealed class School : IDisposable
                 ResetDayLog();
                 // Hung summons do not survive the work morning — same clear as skip empty.
                 DirectorSummonSystem.ClearAll(this);
+        ParentMeetingSystem.ClearAll(this);
             }
 
             peopleChanged = TryYearlyIntake(before, Clock.Time);
@@ -445,6 +455,29 @@ public sealed class School : IDisposable
     public string? DirectorSummonPresenceActionId(string personId) =>
         DirectorSummonSystem.PresenceActionId(DirectorSummonPresencePhase(personId));
 
+    /// <summary>
+    /// Card label while walking to / sitting in a parent meeting without a live activity yet.
+    /// </summary>
+    public string? ParentMeetingPresenceActionId(string personId)
+    {
+        if (!ParentMeetingSystem.IsInMeeting(this, personId))
+        {
+            return null;
+        }
+
+        var session = ActiveParentMeetings.FirstOrDefault(row =>
+            row.TeacherId.Equals(personId, StringComparison.Ordinal)
+            || row.AttendeeIds.Contains(personId));
+        if (session is null)
+        {
+            return null;
+        }
+
+        return session.InProgress && session.TeacherId.Equals(personId, StringComparison.Ordinal)
+            ? HSchool.Ai.ParentMeetings.MeetingAction
+            : HSchool.Ai.ParentMeetings.GoingAction;
+    }
+
     private void RecordWorldEvents(DateTime before, DateTime after)
     {
         _worldEvents.AddRange(EventSystem.Detect(this, before, after));
@@ -469,6 +502,7 @@ public sealed class School : IDisposable
         }
 
         DirectorSummonSystem.Apply(this);
+        ParentMeetingSystem.Apply(this);
 
         PersonDayLog.Sync(this);
 
diff --git a/src/HSchool.Simulation/TalkCircleSystem.cs b/src/HSchool.Simulation/TalkCircleSystem.cs
index 7d0db8a..01f56e6 100644
--- a/src/HSchool.Simulation/TalkCircleSystem.cs
+++ b/src/HSchool.Simulation/TalkCircleSystem.cs
@@ -57,6 +57,7 @@ internal static class TalkCircleSystem
 
         school.ApologyDebts.Clear();
         DirectorSummonSystem.ClearAll(school);
+        ParentMeetingSystem.ClearAll(school);
         school.World.Query(in People, (ref PersonActivity activity) =>
         {
             if (TalkActions.IsConflict(activity.ActionId))
diff --git a/tests/HSchool.Content.Tests/ParentMeetingBehaviorTests.cs b/tests/HSchool.Content.Tests/ParentMeetingBehaviorTests.cs
new file mode 100644
index 0000000..7b25511
--- /dev/null
+++ b/tests/HSchool.Content.Tests/ParentMeetingBehaviorTests.cs
@@ -0,0 +1,54 @@
+using HSchool.Content;
+
+namespace HSchool.Content.Tests;
+
+public class ParentMeetingBehaviorTests
+{
+    private readonly CatalogLoader _loader = new();
+
+    [Fact]
+    public void VanillaRules_LoadParentMeetingThresholds()
+    {
+        var root = Path.Combine(AppContext.BaseDirectory, "vanilla");
+        var documents = new List<ContentDocument>();
+        foreach (var path in Directory.EnumerateFiles(root, "*.*", SearchOption.AllDirectories))
+        {
+            if (!path.EndsWith(".jsonc", StringComparison.OrdinalIgnoreCase)
+                && !path.EndsWith(".json", StringComparison.OrdinalIgnoreCase))
+            {
+                continue;
+            }
+
+            documents.Add(new ContentDocument(
+                CatalogLoader.CorePackId,
+                Path.GetRelativePath(root, path).Replace('\\', '/'),
+                File.ReadAllText(path)));
+        }
+
+        var catalog = _loader.Load([CatalogLoader.CorePackId], documents);
+        Assert.NotNull(catalog.BehaviorRules);
+        Assert.Equal(0.08f, catalog.BehaviorRules.ParentMeetingChance);
+        Assert.Equal(0.4f, catalog.BehaviorRules.ParentMeetingAttendanceFraction);
+        Assert.Equal(20f, catalog.BehaviorRules.ParentMeetingMinutes);
+        Assert.Equal(3, catalog.BehaviorRules.ParentMeetingOpinionShift);
+        Assert.Contains(
+            catalog.Events.Values,
+            row => row.Trigger.Equals(EventTriggers.ParentMeeting, StringComparison.Ordinal));
+    }
+
+    [Fact]
+    public void ParentMeetingChanceOutOfRange_FailsTheCatalog()
+    {
+        var error = Assert.Throws<ContentLoadException>(() => _loader.Load(
+            [CatalogLoader.CorePackId],
+            [
+                PackDocuments.Def(
+                    CatalogLoader.CorePackId,
+                    "behavior",
+                    "rules",
+                    """{ "defName": "Behavior", "parentMeetingChance": 1.5 }"""),
+            ]));
+
+        Assert.Contains("parentMeetingChance", error.Message, StringComparison.Ordinal);
+    }
+}
diff --git a/tests/HSchool.Simulation.Tests/ParentMeetingTests.cs b/tests/HSchool.Simulation.Tests/ParentMeetingTests.cs
new file mode 100644
index 0000000..8828d2c
--- /dev/null
+++ b/tests/HSchool.Simulation.Tests/ParentMeetingTests.cs
@@ -0,0 +1,340 @@
+using Arch.Core;
+using HSchool.Ai;
+using HSchool.Content;
+using HSchool.People;
+using HSchool.Protocol;
+using HSchool.Simulation;
+
+namespace HSchool.Simulation.Tests;
+
+public class ParentMeetingTests
+{
+    private static readonly DateTime TuesdayMorning = new(2012, 4, 3, 6, 0, 0, DateTimeKind.Utc);
+
+    [Fact]
+    public void WithoutClassTeacher_SameDaySeed_DoesNotStart()
+    {
+        var (school, schoolClass, _) = ClassWithParentsAfterLastLesson(assignTeacher: false);
+        using (school)
+        {
+            Assert.Null(schoolClass.ClassTeacherId);
+            Assert.False(ParentMeetingSystem.TryStart(school, schoolClass.Id, chance: 1f, fraction: 1f));
+            Assert.Empty(school.ActiveParentMeetings);
+            Assert.DoesNotContain(
+                school.DrainWorldEvents(),
+                row => row.Trigger.Equals(EventTriggers.ParentMeeting, StringComparison.Ordinal));
+        }
+    }
+
+    [Fact]
+    public void WithClassTeacher_ParentsAppearThenLeaveAfterMeeting()
+    {
+        var (school, schoolClass, teacherId) = ClassWithParentsAfterLastLesson(assignTeacher: true);
+        using (school)
+        {
+            Assert.True(ParentMeetingSystem.TryStart(school, schoolClass.Id, chance: 1f, fraction: 1f));
+            var session = Assert.Single(school.ActiveParentMeetings);
+            Assert.NotEmpty(session.AttendeeIds);
+
+            PlaceAt(school, teacherId, schoolClass.RoomId);
+            foreach (var parentId in session.AttendeeIds)
+            {
+                PlaceAt(school, parentId, schoolClass.RoomId);
+                Assert.Equal(schoolClass.RoomId, NodeOf(school, parentId));
+            }
+
+            ParentMeetingSystem.Apply(school);
+            Assert.True(ActivitySystem.IsParentMeeting(ActivityOf(school, teacherId)));
+
+            ParentMeetingSystem.CompleteMeeting(school, teacherId);
+            Assert.Empty(school.ActiveParentMeetings);
+
+            foreach (var parentId in session.AttendeeIds)
+            {
+                var person = school.Roster!.People.First(row => row.Id == parentId);
+                if (person.IsStaff)
+                {
+                    continue;
+                }
+
+                var node = NodeOf(school, parentId);
+                var headingHome = IsHeadingHome(school, parentId);
+                Assert.True(
+                    node is null || headingHome,
+                    $"Parent {parentId} should leave campus, node={node}, headingHome={headingHome}");
+            }
+        }
+    }
+
+    [Fact]
+    public void MeetingDoesNotStartBeforeLastLessonOfClass()
+    {
+        var (school, schoolClass, teacherId) = ClassWithParents(assignTeacher: true, advancePastLastLesson: false);
+        using (school)
+        {
+            PlaceAt(school, teacherId, schoolClass.RoomId);
+            // Still during period 1 — last lesson has not ended.
+            Assert.False(ParentMeetings.IsAfterLastLesson(
+                school.Catalog!,
+                school.Timetable,
+                schoolClass,
+                school.Clock.Time,
+                school.SchoolWeekDays));
+            Assert.False(ParentMeetingSystem.TryStart(school, schoolClass.Id, chance: 1f, fraction: 1f));
+            Assert.Empty(school.ActiveParentMeetings);
+        }
+    }
+
+    [Fact]
+    public void SameClassAndDaySeed_SameAttendees()
+    {
+        var first = AttendeesFromSeed(seed: 42);
+        var second = AttendeesFromSeed(seed: 42);
+        Assert.Equal(first, second);
+        Assert.NotEmpty(first);
+    }
+
+    [Fact]
+    public void PlayerCannotScheduleMeeting_NoProtocolOrPublicApi()
+    {
+        Assert.DoesNotContain(
+            Enum.GetNames<MessageType>(),
+            name => name.Contains("ParentMeeting", StringComparison.OrdinalIgnoreCase)
+                || name.Contains("Meeting", StringComparison.OrdinalIgnoreCase)
+                    && name.Contains("Parent", StringComparison.OrdinalIgnoreCase));
+        Assert.DoesNotContain(
+            typeof(School).GetMethods(System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.Public),
+            method => method.Name.Contains("Meeting", StringComparison.OrdinalIgnoreCase)
+                && (method.Name.StartsWith("Set", StringComparison.Ordinal)
+                    || method.Name.StartsWith("Start", StringComparison.Ordinal)
+                    || method.Name.StartsWith("Schedule", StringComparison.Ordinal)
+                    || method.Name.StartsWith("Enqueue", StringComparison.Ordinal)));
+    }
+
+    [Fact]
+    public void SkipEmpty_DoesNotLeaveParentsInHomeroom()
+    {
+        var (school, schoolClass, teacherId) = ClassWithParentsAfterLastLesson(assignTeacher: true);
+        using (school)
+        {
+            Assert.True(ParentMeetingSystem.TryStart(school, schoolClass.Id, chance: 1f, fraction: 1f));
+            var session = Assert.Single(school.ActiveParentMeetings);
+            PlaceAt(school, teacherId, schoolClass.RoomId);
+            foreach (var parentId in session.AttendeeIds)
+            {
+                PlaceAt(school, parentId, schoolClass.RoomId);
+            }
+
+            // Jump past the work window so skip is allowed, with campus cleared of pupils/staff
+            // except we force parents off via ClearAll path used by skip.
+            ParentMeetingSystem.ClearAll(school);
+            Assert.Empty(school.ActiveParentMeetings);
+            foreach (var parentId in session.AttendeeIds)
+            {
+                var person = school.Roster!.People.First(row => row.Id == parentId);
+                if (person.IsStaff || person.IsStudent)
+                {
+                    continue;
+                }
+
+                Assert.Null(NodeOf(school, parentId));
+            }
+        }
+    }
+
+    [Fact]
+    public void StartingMeeting_RaisesParentMeetingWorldEvent()
+    {
+        var (school, schoolClass, _) = ClassWithParentsAfterLastLesson(assignTeacher: true);
+        using (school)
+        {
+            school.DrainWorldEvents();
+            Assert.True(ParentMeetingSystem.TryStart(school, schoolClass.Id, chance: 1f, fraction: 1f));
+            var fact = Assert.Single(
+                school.DrainWorldEvents(),
+                row => row.Trigger.Equals(EventTriggers.ParentMeeting, StringComparison.Ordinal));
+            Assert.Equal(schoolClass.ClassTeacherId, fact.PersonKey);
+        }
+    }
+
+    private static IReadOnlyList<string> AttendeesFromSeed(int seed)
+    {
+        var (school, schoolClass, _) = ClassWithParentsAfterLastLesson(assignTeacher: true, seed: seed);
+        using (school)
+        {
+            Assert.True(ParentMeetingSystem.TryStart(school, schoolClass.Id, chance: 1f, fraction: 0.5f));
+            return Assert.Single(school.ActiveParentMeetings).AttendeeIds.ToArray();
+        }
+    }
+
+    private static (School School, SchoolClass Class, string TeacherId) ClassWithParentsAfterLastLesson(
+        bool assignTeacher,
+        int seed = 42) =>
+        ClassWithParents(assignTeacher, advancePastLastLesson: true, seed);
+
+    private static (School School, SchoolClass Class, string TeacherId) ClassWithParents(
+        bool assignTeacher,
+        bool advancePastLastLesson,
+        int seed = 42)
+    {
+        var (catalog, map) = Vanilla();
+        var start = TuesdayMorning;
+        var roster = RosterGenerator.Generate(catalog, map, seed, "Russia", start);
+        var pool = ApplicantPool.Create(catalog, roster, seed, "Russia", start);
+        var schoolClass = roster.Classes.First(row => row.RoomId == "classroom-101");
+        var school = School.Create(seed, "ParentMeeting", start, catalog, map);
+        school.InstallPeople(roster, seed, "Russia", pool);
+        school.SetTimetable(new HSchool.Schedule.Timetable(
+            [
+                new HSchool.Schedule.LessonPlacement(
+                    schoolClass.Id,
+                    "Mathematics",
+                    "t1",
+                    schoolClass.RoomId,
+                    Day: 1,
+                    Period: 1),
+            ],
+            []));
+        school.ConfigurePresence(weekDays: 5, maxDecisionsPerTick: 10_000);
+
+        var teacherId = "";
+        if (assignTeacher)
+        {
+            teacherId = HireTeacher(school);
+            var assigned = ClassTeachers.Assign(school.Roster!, schoolClass.Id, teacherId);
+            Assert.Equal(ClassTeacherError.None, assigned.Error);
+            school.ApplyRosterData(assigned.Roster);
+            schoolClass = school.Roster!.Classes.First(row => row.Id == schoolClass.Id);
+            PlaceAt(school, teacherId, schoolClass.RoomId);
+        }
+
+        if (advancePastLastLesson)
+        {
+            var end = ParentMeetings.LastLessonEnd(catalog, school.Timetable, schoolClass, school.Clock.Time);
+            Assert.NotNull(end);
+            AdvanceTo(school, end.Value.AddMinutes(1));
+            if (assignTeacher)
+            {
+                PlaceAt(school, teacherId, schoolClass.RoomId);
+            }
+        }
+        else if (assignTeacher)
+        {
+            // Mid-lesson: period 1 is still running.
+            var mid = SchoolDay.PeriodStart(catalog.DayFrame!, 1);
+            var midTime = TuesdayMorning.Date + mid.ToTimeSpan() + TimeSpan.FromMinutes(10);
+            AdvanceTo(school, DateTime.SpecifyKind(midTime, DateTimeKind.Utc));
+            PlaceAt(school, teacherId, schoolClass.RoomId);
+        }
+
+        schoolClass = school.Roster!.Classes.First(row => row.Id == schoolClass.Id);
+        return (school, schoolClass, teacherId);
+    }
+
+    private static string HireTeacher(School school)
+    {
+        const float cap = 100_000f;
+        var pool = school.Applicants!;
+        var hired = Staffing.Hire(
+            school.Catalog!,
+            school.Map!,
+            school.Roster!,
+            pool,
+            pool.Applicants[0].Person.Id,
+            Staffing.TeacherPosition,
+            cap);
+        Assert.Equal(StaffingError.None, hired.Error);
+        school.ApplyStaffing(hired.Roster, hired.Pool);
+        return school.Roster!.People.First(person =>
+            person.IsStaff && Staffing.TeacherPosition.Equals(person.Position, StringComparison.Ordinal)).Id;
+    }
+
+    private static void AdvanceTo(School school, DateTime until)
+    {
+        while (school.Clock.Time < until)
+        {
+            school.Tick(0.2d, 5d);
+        }
+    }
+
+    private static void PlaceAt(School school, string personId, string? nodeId)
+    {
+        TalkCircleSystem.Interrupt(school, personId);
+        var query = new QueryDescription().WithAll<PersonIdentity, Presence, PersonActivity, Intent>();
+        school.World.Query(in query, (ref PersonIdentity identity, ref Presence presence, ref PersonActivity activity, ref Intent intent) =>
+        {
+            if (identity.Id.Equals(personId, StringComparison.Ordinal))
+            {
+                presence = nodeId is null ? Presence.OffCampus : new Presence(nodeId, 0f, nodeId, false, []);
+                activity = PersonActivity.Idle;
+                intent = Intent.None;
+            }
+        });
+    }
+
+    private static string? NodeOf(School school, string personId)
+    {
+        string? found = null;
+        var query = new QueryDescription().WithAll<PersonIdentity, Presence>();
+        school.World.Query(in query, (ref PersonIdentity identity, ref Presence presence) =>
+        {
+            if (identity.Id.Equals(personId, StringComparison.Ordinal))
+            {
+                found = presence.NodeId;
+            }
+        });
+        return found;
+    }
+
+    private static bool IsHeadingHome(School school, string personId)
+    {
+        var heading = false;
+        var query = new QueryDescription().WithAll<PersonIdentity, Presence>();
+        school.World.Query(in query, (ref PersonIdentity identity, ref Presence presence) =>
+        {
+            if (identity.Id.Equals(personId, StringComparison.Ordinal))
+            {
+                heading = presence.HeadingHome;
+            }
+        });
+        return heading;
+    }
+
+    private static string? ActivityOf(School school, string personId)
+    {
+        string? found = null;
+        var query = new QueryDescription().WithAll<PersonIdentity, PersonActivity>();
+        school.World.Query(in query, (ref PersonIdentity identity, ref PersonActivity activity) =>
+        {
+            if (identity.Id.Equals(personId, StringComparison.Ordinal) && activity.IsActive)
+            {
+                found = activity.ActionId;
+            }
+        });
+        return found;
+    }
+
+    private static (DefCatalog Catalog, MapLayout Map) Vanilla()
+    {
+        var root = Path.Combine(AppContext.BaseDirectory, "vanilla");
+        var documents = new List<ContentDocument>();
+        foreach (var path in Directory.EnumerateFiles(root, "*.*", SearchOption.AllDirectories))
+        {
+            if (!path.EndsWith(".jsonc", StringComparison.OrdinalIgnoreCase)
+                && !path.EndsWith(".json", StringComparison.OrdinalIgnoreCase))
+            {
+                continue;
+            }
+
+            documents.Add(new ContentDocument(
+                CatalogLoader.CorePackId,
+                Path.GetRelativePath(root, path).Replace('\\', '/'),
+                File.ReadAllText(path)));
+        }
+
+        var catalog = new CatalogLoader().Load([CatalogLoader.CorePackId], documents);
+        var map = CatalogLoader.LastDefaultMap([CatalogLoader.CorePackId], documents);
+        Assert.NotNull(map);
+        return (catalog, map);
+    }
+}