diff --git a/bridge/tests/test_tutorial_flow.py b/bridge/tests/test_tutorial_flow.py
new file mode 100644
index 0000000..a088f16
--- /dev/null
+++ b/bridge/tests/test_tutorial_flow.py
@@ -0,0 +1,229 @@
+"""Tests for tutorial / campaign flow state machine + scenario JSONs.
+
+PRD acceptance #9: Tutorial completes <10 min, transitions to long-running campaign.
+PRD acceptance #20: Tutorial→campaign handoff works in same session.
+"""
+
+import json
+from pathlib import Path
+
+import pytest
+
+from bridge.tutorial import (
+    CAMPAIGN_ACTIVE,
+    DEFAULT_TUTORIAL_FILENAME,
+    NOT_STARTED,
+    TUTORIAL_ACTIVE,
+    TUTORIAL_COMPLETE,
+    TutorialFlow,
+    TutorialFlowError,
+    TutorialStore,
+    scenario_to_load,
+)
+
+
+REPO_ROOT = Path(__file__).resolve().parents[2]
+SCENARIO_ROOT = REPO_ROOT / "mod" / "ClaudeKingdoms" / "scenarios"
+
+
+# ────────────────────────────────────────────────────────────────────────
+# State machine
+# ────────────────────────────────────────────────────────────────────────
+
+def test_initial_state_is_not_started():
+    flow = TutorialFlow()
+    assert flow.state == NOT_STARTED
+    assert flow.turns_in_tutorial == 0
+    assert flow.is_ready_for_campaign() is False
+
+
+def test_full_happy_path_transitions():
+    flow = TutorialFlow()
+    flow.transition(TUTORIAL_ACTIVE)
+    assert flow.started_at is not None
+    flow.record_tutorial_turn()
+    assert flow.turns_in_tutorial == 1
+    flow.transition(TUTORIAL_COMPLETE)
+    assert flow.completed_at is not None
+    assert flow.is_ready_for_campaign() is True
+    flow.transition(CAMPAIGN_ACTIVE)
+    assert flow.state == CAMPAIGN_ACTIVE
+
+
+def test_skip_tutorial_path():
+    flow = TutorialFlow()
+    flow.transition(CAMPAIGN_ACTIVE)
+    assert flow.state == CAMPAIGN_ACTIVE
+    assert flow.completed_at is not None  # set even on skip
+
+
+def test_illegal_transition_raises():
+    flow = TutorialFlow()
+    with pytest.raises(TutorialFlowError):
+        flow.transition(TUTORIAL_COMPLETE)  # not_started → complete is illegal
+
+
+def test_record_turn_only_in_tutorial_active():
+    flow = TutorialFlow()
+    flow.record_tutorial_turn()  # NOT_STARTED — should be a no-op
+    assert flow.turns_in_tutorial == 0
+    flow.transition(TUTORIAL_ACTIVE)
+    flow.record_tutorial_turn()
+    flow.record_tutorial_turn()
+    assert flow.turns_in_tutorial == 2
+    flow.transition(TUTORIAL_COMPLETE)
+    flow.record_tutorial_turn()  # past the tutorial — no-op
+    assert flow.turns_in_tutorial == 2
+
+
+def test_replay_tutorial_after_complete():
+    flow = TutorialFlow()
+    flow.transition(TUTORIAL_ACTIVE)
+    flow.transition(TUTORIAL_COMPLETE)
+    flow.transition(TUTORIAL_ACTIVE)  # replay allowed
+    assert flow.state == TUTORIAL_ACTIVE
+
+
+def test_campaign_is_terminal_no_back_to_tutorial():
+    flow = TutorialFlow()
+    flow.transition(CAMPAIGN_ACTIVE)
+    with pytest.raises(TutorialFlowError):
+        flow.transition(TUTORIAL_ACTIVE)
+
+
+# ────────────────────────────────────────────────────────────────────────
+# Persistence
+# ────────────────────────────────────────────────────────────────────────
+
+def test_tutorial_store_round_trip(tmp_path):
+    store = TutorialStore(tmp_path / "state")
+    flow = TutorialFlow()
+    flow.transition(TUTORIAL_ACTIVE)
+    flow.record_tutorial_turn()
+    store.save(flow)
+
+    reloaded = TutorialStore(tmp_path / "state").load()
+    assert reloaded.state == TUTORIAL_ACTIVE
+    assert reloaded.turns_in_tutorial == 1
+    assert reloaded.started_at is not None
+
+
+def test_tutorial_store_default_filename_when_dir(tmp_path):
+    store = TutorialStore(tmp_path / "state")
+    assert store.path.name == DEFAULT_TUTORIAL_FILENAME
+
+
+def test_tutorial_store_explicit_path(tmp_path):
+    custom = tmp_path / "custom.json"
+    store = TutorialStore(custom)
+    assert store.path == custom
+
+
+def test_tutorial_store_load_missing_returns_default(tmp_path):
+    store = TutorialStore(tmp_path / "state")
+    flow = store.load()
+    assert flow.state == NOT_STARTED
+
+
+def test_tutorial_store_load_corrupt_returns_default(tmp_path):
+    path = tmp_path / "tutorial_state.json"
+    path.write_text("not json", encoding="utf-8")
+    flow = TutorialStore(path).load()
+    assert flow.state == NOT_STARTED
+
+
+def test_tutorial_store_reset_removes_file(tmp_path):
+    store = TutorialStore(tmp_path / "state")
+    flow = TutorialFlow()
+    flow.transition(TUTORIAL_ACTIVE)
+    store.save(flow)
+    assert store.path.exists()
+    store.reset()
+    assert not store.path.exists()
+
+
+def test_atomic_write_no_temp_files_on_disk(tmp_path):
+    store = TutorialStore(tmp_path / "state")
+    flow = TutorialFlow()
+    flow.transition(TUTORIAL_ACTIVE)
+    store.save(flow)
+    leftover = list(store.path.parent.glob(".tutorial_*"))
+    assert leftover == []
+
+
+# ────────────────────────────────────────────────────────────────────────
+# scenario_to_load
+# ────────────────────────────────────────────────────────────────────────
+
+def test_scenario_loader_returns_tutorial_when_not_yet_done():
+    flow = TutorialFlow()
+    assert scenario_to_load(flow) == "Tutorial"
+    flow.transition(TUTORIAL_ACTIVE)
+    assert scenario_to_load(flow) == "Tutorial"
+
+
+def test_scenario_loader_returns_campaign_after_completion():
+    flow = TutorialFlow()
+    flow.transition(TUTORIAL_ACTIVE)
+    flow.transition(TUTORIAL_COMPLETE)
+    assert scenario_to_load(flow) == "LongRunningCampaign"
+
+
+def test_scenario_loader_returns_campaign_after_skip():
+    flow = TutorialFlow()
+    flow.transition(CAMPAIGN_ACTIVE)
+    assert scenario_to_load(flow) == "LongRunningCampaign"
+
+
+# ────────────────────────────────────────────────────────────────────────
+# Scenario JSON files (mod-side content)
+# ────────────────────────────────────────────────────────────────────────
+
+def test_tutorial_scenario_files_parse():
+    for name in ("scenario.json", "Map.json"):
+        path = SCENARIO_ROOT / "Tutorial" / name
+        assert path.exists(), f"missing {path}"
+        json.loads(path.read_text(encoding="utf-8"))
+
+
+def test_campaign_scenario_files_parse():
+    for name in ("scenario.json", "Map.json"):
+        path = SCENARIO_ROOT / "LongRunningCampaign" / name
+        assert path.exists(), f"missing {path}"
+        json.loads(path.read_text(encoding="utf-8"))
+
+
+def test_tutorial_scenario_specifies_under_ten_minutes():
+    """PRD acceptance #9 anchor."""
+    data = json.loads((SCENARIO_ROOT / "Tutorial" / "scenario.json").read_text())
+    assert data["tutorialFlags"]["expectedDurationMinutes"] <= 10
+
+
+def test_tutorial_scenario_handoff_target_is_campaign():
+    data = json.loads((SCENARIO_ROOT / "Tutorial" / "scenario.json").read_text())
+    assert data["claudeKingdomsMeta"]["handoffTarget"] == "LongRunningCampaign"
+
+
+def test_campaign_scenario_has_no_forced_end_condition():
+    """PRD acceptance #18: no forced end."""
+    data = json.loads((SCENARIO_ROOT / "LongRunningCampaign" / "scenario.json").read_text())
+    assert data["victoryConditions"] == []
+    assert data["campaignFlags"]["noForcedEnd"] is True
+
+
+def test_campaign_scenario_supports_no_decay():
+    """PRD acceptance #16, BS-6: state preserved on close."""
+    data = json.loads((SCENARIO_ROOT / "LongRunningCampaign" / "scenario.json").read_text())
+    assert data["campaignFlags"]["noDecayOnClose"] is True
+
+
+def test_tutorial_map_has_a_starting_city():
+    """The tutorial must place exactly one city — PRD: 'one city, one session, one turn'."""
+    data = json.loads((SCENARIO_ROOT / "Tutorial" / "Map.json").read_text())
+    cities = []
+    for row in data["tiles"]:
+        for tile in row:
+            if tile.get("city"):
+                cities.append(tile["city"])
+    assert len(cities) == 1
+    assert cities[0] == "Camelot"
diff --git a/bridge/tutorial.py b/bridge/tutorial.py
new file mode 100644
index 0000000..65d3547
--- /dev/null
+++ b/bridge/tutorial.py
@@ -0,0 +1,173 @@
+"""Tutorial / campaign handoff state machine (PRD acceptance #9, #20).
+
+Tracks where a player is in the tutorial-to-campaign flow:
+
+  not_started → tutorial_active → tutorial_complete → campaign_active
+
+The PRD pins the tutorial deliverable as: 'Under ten minutes. One city,
+one session, one turn, one reward. Shows the emotional payoff before
+explaining mechanics.' Once the player achieves the first scripted
+turn-reward, the flow advances to `tutorial_complete`. The next time
+the bridge daemon runs (or the user explicitly transitions), the flow
+moves to `campaign_active` and stays there.
+
+The state is persisted as a small JSON file (separate from the save
+exchange) so:
+  * tutorial completion survives close/reopen (PRD §BS-6 no-decay),
+  * the Unciv mod can poll it at scenario-load time to decide which
+    map to load.
+"""
+
+from __future__ import annotations
+
+import json
+import os
+import tempfile
+from dataclasses import dataclass, field
+from datetime import datetime
+from pathlib import Path
+from typing import Optional
+
+
+DEFAULT_TUTORIAL_FILENAME = "tutorial_state.json"
+
+
+# ────────────────────────────────────────────────────────────────────────
+# State machine
+# ────────────────────────────────────────────────────────────────────────
+
+NOT_STARTED = "not_started"
+TUTORIAL_ACTIVE = "tutorial_active"
+TUTORIAL_COMPLETE = "tutorial_complete"
+CAMPAIGN_ACTIVE = "campaign_active"
+
+
+VALID_TRANSITIONS = {
+    NOT_STARTED: {TUTORIAL_ACTIVE, CAMPAIGN_ACTIVE},  # can skip tutorial
+    TUTORIAL_ACTIVE: {TUTORIAL_COMPLETE, NOT_STARTED},  # complete or restart
+    TUTORIAL_COMPLETE: {CAMPAIGN_ACTIVE, TUTORIAL_ACTIVE},  # graduate or replay
+    CAMPAIGN_ACTIVE: {CAMPAIGN_ACTIVE},  # terminal — campaign is the long-running mode
+}
+
+
+class TutorialFlowError(Exception):
+    """Raised on illegal state transitions."""
+
+
+@dataclass
+class TutorialFlow:
+    """In-memory tutorial flow state — persisted via TutorialStore."""
+    state: str = NOT_STARTED
+    turns_in_tutorial: int = 0
+    completed_at: Optional[str] = None
+    started_at: Optional[str] = None
+
+    def transition(self, new_state: str) -> None:
+        if new_state not in VALID_TRANSITIONS.get(self.state, set()):
+            raise TutorialFlowError(
+                f"illegal transition: {self.state!r} → {new_state!r}"
+            )
+        self.state = new_state
+        now = datetime.now().astimezone().isoformat()
+        if new_state == TUTORIAL_ACTIVE and self.started_at is None:
+            self.started_at = now
+        if new_state == TUTORIAL_COMPLETE:
+            self.completed_at = now
+        if new_state == CAMPAIGN_ACTIVE and self.completed_at is None:
+            # Skipped tutorial — record completion so reset() works cleanly.
+            self.completed_at = now
+
+    def record_tutorial_turn(self) -> None:
+        if self.state != TUTORIAL_ACTIVE:
+            return
+        self.turns_in_tutorial += 1
+
+    def is_ready_for_campaign(self) -> bool:
+        """True when the player has finished the tutorial and is ready
+        to be handed off to the long-running campaign map."""
+        return self.state == TUTORIAL_COMPLETE
+
+    def to_dict(self) -> dict:
+        return {
+            "state": self.state,
+            "turns_in_tutorial": self.turns_in_tutorial,
+            "started_at": self.started_at,
+            "completed_at": self.completed_at,
+        }
+
+    @classmethod
+    def from_dict(cls, data: dict) -> "TutorialFlow":
+        return cls(
+            state=data.get("state", NOT_STARTED),
+            turns_in_tutorial=int(data.get("turns_in_tutorial", 0) or 0),
+            started_at=data.get("started_at"),
+            completed_at=data.get("completed_at"),
+        )
+
+
+# ────────────────────────────────────────────────────────────────────────
+# Persistent store
+# ────────────────────────────────────────────────────────────────────────
+
+class TutorialStore:
+    """File-backed persistence for TutorialFlow.
+
+    Atomic writes via temp-file + rename — the same pattern as
+    SaveExchange so a crash mid-write never corrupts the state file.
+    """
+
+    def __init__(self, path: str | Path):
+        p = Path(path)
+        if p.suffix == "":
+            p.mkdir(parents=True, exist_ok=True)
+            p = p / DEFAULT_TUTORIAL_FILENAME
+        else:
+            p.parent.mkdir(parents=True, exist_ok=True)
+        self.path: Path = p
+
+    def load(self) -> TutorialFlow:
+        if not self.path.exists():
+            return TutorialFlow()
+        try:
+            with open(self.path, "r", encoding="utf-8") as f:
+                data = json.load(f)
+        except (json.JSONDecodeError, OSError):
+            return TutorialFlow()
+        return TutorialFlow.from_dict(data)
+
+    def save(self, flow: TutorialFlow) -> Path:
+        body = json.dumps(flow.to_dict(), indent=2)
+        fd, tmp_path = tempfile.mkstemp(prefix=".tutorial_", suffix=".tmp",
+                                         dir=str(self.path.parent))
+        try:
+            with os.fdopen(fd, "w", encoding="utf-8") as f:
+                f.write(body)
+            os.replace(tmp_path, self.path)
+        except Exception:
+            try:
+                os.unlink(tmp_path)
+            except OSError:
+                pass
+            raise
+        return self.path
+
+    def reset(self) -> None:
+        """Forget tutorial state entirely (back to NOT_STARTED on next load)."""
+        if self.path.exists():
+            self.path.unlink()
+
+
+# ────────────────────────────────────────────────────────────────────────
+# Helper: scenario the Unciv mod should load
+# ────────────────────────────────────────────────────────────────────────
+
+def scenario_to_load(flow: TutorialFlow) -> str:
+    """Returns the scenario filename the Unciv mod should load.
+
+    Maps each flow state to one of two scenarios shipped in
+    `mod/ClaudeKingdoms/scenarios/`. Fallback is the campaign map
+    (no-tutorial = direct-to-campaign).
+    """
+    if flow.state in (NOT_STARTED, TUTORIAL_ACTIVE):
+        return "Tutorial"
+    return "LongRunningCampaign"
diff --git a/mod/ClaudeKingdoms/scenarios/LongRunningCampaign/Map.json b/mod/ClaudeKingdoms/scenarios/LongRunningCampaign/Map.json
new file mode 100644
index 0000000..26c9d1c
--- /dev/null
+++ b/mod/ClaudeKingdoms/scenarios/LongRunningCampaign/Map.json
@@ -0,0 +1,20 @@
+{
+  "mapParameters": {
+    "name": "Albion",
+    "type": "Custom",
+    "size": {"width": 12, "height": 8},
+    "shape": "Rectangular",
+    "noNaturalWonders": false,
+    "noBarbarians": false
+  },
+  "tiles": [
+    [{"terrain": "Coast"},   {"terrain": "Coast"},   {"terrain": "Plains"},  {"terrain": "Hill"},    {"terrain": "Plains"},  {"terrain": "Forest"},  {"terrain": "Plains"},  {"terrain": "Hill"},    {"terrain": "Plains"},  {"terrain": "Mountain"},{"terrain": "Hill"},    {"terrain": "Coast"}],
+    [{"terrain": "Coast"},   {"terrain": "Plains"},  {"terrain": "Grassland"},{"terrain": "Plains"}, {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Forest"},  {"terrain": "Plains"},  {"terrain": "Hill"},    {"terrain": "Hill"},    {"terrain": "Plains"},  {"terrain": "Coast"}],
+    [{"terrain": "Plains"},  {"terrain": "Grassland"},{"terrain": "Grassland", "city": "Camelot", "owner": "The Operators", "startingPosition": true}, {"terrain": "Grassland"},{"terrain": "Plains"}, {"terrain": "Forest"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Hill"},    {"terrain": "Plains"},  {"terrain": "Plains"}],
+    [{"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Grassland"},{"terrain": "Plains"}, {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Forest"},  {"terrain": "Plains"}],
+    [{"terrain": "Plains"},  {"terrain": "Forest"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Hill"},    {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"}],
+    [{"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Hill"},    {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Forest"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"}],
+    [{"terrain": "Coast"},   {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Coast"}],
+    [{"terrain": "Coast"},   {"terrain": "Coast"},   {"terrain": "Coast"},   {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Coast"},   {"terrain": "Coast"},   {"terrain": "Coast"}]
+  ]
+}
diff --git a/mod/ClaudeKingdoms/scenarios/LongRunningCampaign/scenario.json b/mod/ClaudeKingdoms/scenarios/LongRunningCampaign/scenario.json
new file mode 100644
index 0000000..e534de8
--- /dev/null
+++ b/mod/ClaudeKingdoms/scenarios/LongRunningCampaign/scenario.json
@@ -0,0 +1,20 @@
+{
+  "name": "LongRunningCampaign",
+  "description": "Persistent medieval world that grows across days and weeks. No decay on close. No forced end condition. The primary mode.",
+  "mapSize": "Standard",
+  "civilizations": [
+    {"civ": "The Operators", "playerType": "Human", "startCity": "Camelot"}
+  ],
+  "startingTechs": ["Pottery", "Animal Husbandry"],
+  "startingTurn": 1,
+  "victoryConditions": [],
+  "campaignFlags": {
+    "noForcedEnd": true,
+    "noDecayOnClose": true,
+    "supportMultipleSessions": true
+  },
+  "claudeKingdomsMeta": {
+    "scenarioRole": "campaign",
+    "prdAnchor": "PRD §Game Modes (Long-Running Campaign — Primary Mode)"
+  }
+}
diff --git a/mod/ClaudeKingdoms/scenarios/Tutorial/Map.json b/mod/ClaudeKingdoms/scenarios/Tutorial/Map.json
new file mode 100644
index 0000000..b215439
--- /dev/null
+++ b/mod/ClaudeKingdoms/scenarios/Tutorial/Map.json
@@ -0,0 +1,18 @@
+{
+  "mapParameters": {
+    "name": "Tutorial Hill",
+    "type": "Custom",
+    "size": {"width": 6, "height": 6},
+    "shape": "Rectangular",
+    "noNaturalWonders": true,
+    "noBarbarians": true
+  },
+  "tiles": [
+    [{"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Hill"},   {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Forest"}],
+    [{"terrain": "Plains"},  {"terrain": "Grassland"},{"terrain": "Grassland", "city": "Camelot", "owner": "The Operators", "startingPosition": true}, {"terrain": "Grassland"},{"terrain": "Plains"},  {"terrain": "Plains"}],
+    [{"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"}, {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Hill"}],
+    [{"terrain": "Forest"},  {"terrain": "Plains"},  {"terrain": "Plains"}, {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Plains"}],
+    [{"terrain": "Hill"},    {"terrain": "Plains"},  {"terrain": "Plains"}, {"terrain": "Plains"},  {"terrain": "Plains"},  {"terrain": "Forest"}],
+    [{"terrain": "Plains"},  {"terrain": "Forest"},  {"terrain": "Plains"}, {"terrain": "Plains"},  {"terrain": "Hill"},    {"terrain": "Plains"}]
+  ]
+}
diff --git a/mod/ClaudeKingdoms/scenarios/Tutorial/scenario.json b/mod/ClaudeKingdoms/scenarios/Tutorial/scenario.json
new file mode 100644
index 0000000..d0b1f9b
--- /dev/null
+++ b/mod/ClaudeKingdoms/scenarios/Tutorial/scenario.json
@@ -0,0 +1,21 @@
+{
+  "name": "Tutorial",
+  "description": "One city, one session, one turn, one reward. Under ten minutes. Shows the emotional payoff before explaining mechanics.",
+  "mapSize": "Tiny",
+  "civilizations": [
+    {"civ": "The Operators", "playerType": "Human", "startCity": "Camelot"}
+  ],
+  "startingTechs": ["Pottery"],
+  "startingTurn": 1,
+  "victoryConditions": ["Tutorial Complete"],
+  "tutorialFlags": {
+    "graduateAfterTurn": 1,
+    "showOnboardingFirst": true,
+    "expectedDurationMinutes": 10
+  },
+  "claudeKingdomsMeta": {
+    "scenarioRole": "tutorial",
+    "handoffTarget": "LongRunningCampaign",
+    "prdAnchor": "acceptance #9 (Tutorial completes <10 min, transitions to long-running campaign)"
+  }
+}