diff --git a/client/scripts/newgame/new_game.gd b/client/scripts/newgame/new_game.gd
new file mode 100644
index 0000000..6ed2cac
--- /dev/null
+++ b/client/scripts/newgame/new_game.gd
@@ -0,0 +1,70 @@
+class_name NewGame
+extends RefCounted
+## New-game construction (spec "New-game construction"). Reads three immutable
+## inputs (origin, world, creation) and writes two products (CanonLog, GameState).
+## Nothing flows back up — charter §2 on the client. Validation is front-loaded:
+## a broken origin or illegal class fails here, loudly, not three scenes later.
+
+static func construct(origin: Dictionary, world: ContentDB, creation: Dictionary, rng: RandomNumberGenerator) -> Dictionary:
+	var errors: Array = []
+
+	# 1. content integrity — every referenced id must resolve in world content.
+	for ref in world.unresolved_refs(origin):
+		errors.append("unresolved ref: %s" % ref)
+
+	# 2. build constraints — chosen class must be allowed by the origin.
+	var bc: Dictionary = origin.get("build_constraints", {})
+	var allowed: Array = bc.get("allowed_classes", [])
+	var class_id: String = creation.get("class_id", "")
+	if class_id not in allowed:
+		errors.append("class not allowed by origin: %s" % class_id)
+
+	if not errors.is_empty():
+		return {"ok": false, "errors": errors, "log": null, "state": null}
+
+	# 3. roll Luck (numeric -> state only) and 4. the stat block (data only).
+	var state := GameState.new()
+	state.luck_base = Luck.roll_base(rng, int(bc.get("luck_modifier", 0)))
+	state.luck = state.luck_base
+	state.stats = {
+		"str": _roll_stat(rng), "dex": _roll_stat(rng), "con": _roll_stat(rng),
+		"fth": _roll_stat(rng), "mag": _roll_stat(rng),
+	}
+
+	# 5. assemble the canon log.
+	var log := CanonLog.new()
+	log.player = LogPlayer.new(creation.get("name", ""), class_id, state.luck_descriptor())
+
+	var loc: Dictionary = world.location(origin["start_location_id"])
+	log.set_location(loc.get("id", ""), loc.get("name", ""))
+
+	var overrides: Dictionary = origin.get("disposition_overrides", {})
+	var companion_ids := {}
+	for c in world.companions():
+		companion_ids[c["id"]] = true
+		log.party.append(PartyMember.new(c["id"], c.get("name", ""), int(overrides.get(c["id"], 0))))
+	# non-companion overrides go to game state, never the log (spec §5 / charter §6).
+	for npc_id in overrides:
+		if not companion_ids.has(npc_id):
+			state.set_npc_disposition(npc_id, int(overrides[npc_id]))
+
+	for line in origin.get("situation", []):
+		log.push_event(line)
+	for fact in origin.get("opening_facts", []):
+		log.add_fact(fact)
+
+	var quest_id: Variant = origin.get("start_quest_id", null)
+	if quest_id != null:
+		var qd: Dictionary = world.quest(quest_id)
+		log.active_quests.append(Quest.new(qd.get("id", ""), qd.get("name", ""), "active", qd.get("objective", "")))
+
+	# inventory grants -> game state (NOT the log). Charter §2.
+	for grant in origin.get("inventory_grants", []):
+		state.add_item(grant.get("item_id", ""), int(grant.get("qty", 0)))
+
+	return {"ok": true, "errors": [], "log": log, "state": state}
+
+
+static func _roll_stat(rng: RandomNumberGenerator) -> int:
+	# 3d6 placeholder; the stat block is data-only in this plan. TUNABLE.
+	return rng.randi_range(1, 6) + rng.randi_range(1, 6) + rng.randi_range(1, 6)
diff --git a/client/scripts/newgame/new_game.gd.uid b/client/scripts/newgame/new_game.gd.uid
new file mode 100644
index 0000000..fa799da
--- /dev/null
+++ b/client/scripts/newgame/new_game.gd.uid
@@ -0,0 +1 @@
+uid://cju7c1s06onrd
diff --git a/client/tests/unit/test_new_game.gd b/client/tests/unit/test_new_game.gd
new file mode 100644
index 0000000..365706a
--- /dev/null
+++ b/client/tests/unit/test_new_game.gd
@@ -0,0 +1,87 @@
+extends "res://addons/gut/test.gd"
+
+const NewGame = preload("res://scripts/newgame/new_game.gd")
+const ContentDB = preload("res://scripts/content/content_db.gd")
+
+var world
+
+
+func before_each():
+	world = ContentDB.new()
+	world.load_from(ContentDB.default_content_root())
+
+
+func _deserter() -> Dictionary:
+	return ContentDB.load_json(ContentDB.origin_path("deserter"))
+
+
+func _rng() -> RandomNumberGenerator:
+	var r := RandomNumberGenerator.new()
+	r.seed = 7
+	return r
+
+
+func _build(creation: Dictionary) -> Dictionary:
+	return NewGame.construct(_deserter(), world, creation, _rng())
+
+
+func test_construct_succeeds():
+	var res := _build({"name": "Aldric", "class_id": "sellsword"})
+	assert_true(res["ok"], str(res["errors"]))
+
+
+func test_numeric_luck_absent_from_log():
+	var res := _build({"name": "Aldric", "class_id": "sellsword"})
+	var pd: Dictionary = res["log"].player.to_dict()
+	assert_false("luck" in pd)
+	assert_eq(pd.keys().size(), 3)
+	assert_true(res["state"].luck >= Luck.MIN and res["state"].luck <= Luck.MAX)
+
+
+func test_inventory_and_dispo_land_in_state_not_log():
+	var res := _build({"name": "Aldric", "class_id": "sellsword"})
+	assert_eq(res["state"].inventory.get("coin", 0), 3)
+	assert_eq(res["state"].inventory.get("worn_shortsword", 0), 1)
+	assert_false("inventory" in res["log"].to_dict())
+
+
+func test_companion_dispositions_from_overrides():
+	var res := _build({"name": "Aldric", "class_id": "sellsword"})
+	assert_eq(res["log"].party_member("brannoc_thane").disposition, 40)
+	assert_eq(res["log"].party_member("cadwyn_vell").disposition, 15)
+
+
+func test_situation_and_facts_seeded():
+	var res := _build({"name": "Aldric", "class_id": "sellsword"})
+	assert_eq(res["log"].recent_events.size(), 2)
+	assert_true("the player deserted the Iron Kettle mercenary company" in res["log"].established_facts)
+	assert_eq(res["log"].humiliations.size(), 0)
+
+
+func test_active_quest_resolved_from_world():
+	var res := _build({"name": "Aldric", "class_id": "sellsword"})
+	assert_eq(res["log"].active_quests.size(), 1)
+	assert_eq(res["log"].active_quests[0].id, "find_the_ledger")
+	assert_eq(res["log"].active_quests[0].status, "active")
+
+
+func test_null_start_quest_yields_no_quest():
+	var o := _deserter()
+	o["start_quest_id"] = null
+	var res := NewGame.construct(o, world, {"name": "X", "class_id": "sellsword"}, _rng())
+	assert_eq(res["log"].active_quests.size(), 0)
+
+
+func test_class_not_allowed_is_rejected():
+	var res := _build({"name": "X", "class_id": "berserker"})
+	assert_false(res["ok"])
+	assert_true(res["errors"].size() > 0)
+	assert_null(res["log"])
+
+
+func test_unresolved_origin_is_rejected():
+	var o := _deserter()
+	o["start_location_id"] = "nowhere"
+	var res := NewGame.construct(o, world, {"name": "X", "class_id": "sellsword"}, _rng())
+	assert_false(res["ok"])
+	assert_true("unresolved ref: location:nowhere" in res["errors"])
diff --git a/client/tests/unit/test_new_game.gd.uid b/client/tests/unit/test_new_game.gd.uid
new file mode 100644
index 0000000..de8a486
--- /dev/null
+++ b/client/tests/unit/test_new_game.gd.uid
@@ -0,0 +1 @@
+uid://gwhuesdye0xa