diff --git a/docs/music-data.md b/docs/music-data.md
index 64c7e00..75abf3c 100644
--- a/docs/music-data.md
+++ b/docs/music-data.md
@@ -353,6 +353,8 @@ column should be parsed as 32-bit floats.
 Tables with a column list export those columns, and every row must have them. Tables marked "all" export every
 column their rows have, in the order the rows first have them; when such a table has no rows, `columns` is empty
 (the master data carries no field list for an empty table). A reader treats a table missing from `master` as empty.
+`MasterCharacter._isNonPlayable` is the game's flag for a non-playable character; a row without it is written as
+`false`.
 
 | Table | Columns |
 |---|---|
@@ -364,7 +366,7 @@ column their rows have, in the order the rows first have them; when such a table
 | `MasterSupportCard` | `_id` `_characterIDs` `_rarity` `_cardType` `_performancePowerMax` `_technicPowerMax` `_visualPowerMax` `_supportCardLevelGroup` `_supportCardRankGroup` `_supportSkillId01` `_supportSkillId02` `_gekisouSupportSkillId01` `_gekisouSupportSkillId02` |
 | `MasterSupportCardLevel` | `_id` `_group` `_level` `_exp` `_performanceRate` `_technicRate` `_visualRate` |
 | `MasterSupportCardRank` | `_id` `_group` `_rank` `_limitLevel` `_cardTypeLinkBonusRate` `_supportSkill01Level` `_supportSkill02Level` `_gekisouSupportSkill01Level` `_gekisouSupportSkill02Level` |
-| `MasterCharacter` | `_id` `_bandID` |
+| `MasterCharacter` | `_id` `_bandID` `_isNonPlayable` |
 | `MasterBand` | `_id` |
 | `MasterCharacterRank` | `_id` `_rank` `_exp` `_bonus` |
 | `MasterCharacterTotalRank` | `_id` `_totalRank` `_bonus` |
diff --git a/src/nnnotes/deckdata.py b/src/nnnotes/deckdata.py
index f0855c7..8c28e07 100644
--- a/src/nnnotes/deckdata.py
+++ b/src/nnnotes/deckdata.py
@@ -28,7 +28,7 @@
 from pathlib import Path
 
 from .apkset import ApkSet
-from typing import Callable
+from typing import Any, Callable
 
 DECK_FORMAT = "nnnotes.deck-data/1"         # the deck model's input format (ournotes-sim data::FORMAT)
 CHART_FORMAT = "nnnotes.live-score/1"      # score.convert's format: the converter the notes come from
@@ -44,6 +44,9 @@
                  "_effectExecuteLimitResetConditionGroup")
 _WHOLE = None                              # every column of the table, in the order the rows first have them
 
+# {table: {column: value}}: columns exported with this value when a row does not have them
+DEFAULTS: dict[str, dict[str, Any]] = {"MasterCharacter": {"_isNonPlayable": False}}
+
 # (table, columns), in file order. A table with a column list exports those columns; a whole table all of its own.
 TABLES: tuple[tuple[str, tuple[str, ...] | None], ...] = tuple(
     (t, None if c is _WHOLE else tuple(c.split())) for t, c in (
@@ -61,7 +64,7 @@
     ("MasterSupportCardLevel", "_id _group _level _exp _performanceRate _technicRate _visualRate"),
     ("MasterSupportCardRank", "_id _group _rank _limitLevel _cardTypeLinkBonusRate _supportSkill01Level "
                               "_supportSkill02Level _gekisouSupportSkill01Level _gekisouSupportSkill02Level"),
-    ("MasterCharacter", "_id _bandID"),
+    ("MasterCharacter", "_id _bandID _isNonPlayable"),
     ("MasterBand", "_id"),
     ("MasterCharacterRank", "_id _rank _exp _bonus"),
     ("MasterCharacterTotalRank", "_id _totalRank _bonus"),
@@ -280,7 +283,8 @@ def _value(v, where: str):
 
 def master_subset(tables: dict[str, list[dict]]) -> dict:
     """{table: {"columns", "rows"}} for TABLES, rows in the served order. A table with a column list must have each
-    of them in every row; a whole table exports the columns its rows have (none when it has no rows)."""
+    of them in every row, except the columns of DEFAULTS (written as their default when a row lacks them); a whole
+    table exports the columns its rows have (none when it has no rows)."""
     out = {}
     for name, cols in TABLES:
         rows = tables[name]
@@ -289,12 +293,14 @@ def master_subset(tables: dict[str, list[dict]]) -> dict:
             for r in rows:
                 seen.update(dict.fromkeys(r))
             cols = tuple(seen)
+        defaults = DEFAULTS.get(name, {})
         for i, r in enumerate(rows):
-            missing = [c for c in cols if c not in r]
+            missing = [c for c in cols if c not in r and c not in defaults]
             if missing:
                 raise DeckDataError(f"{name}: row {i} (_id {r.get('_id')}) has no column {missing[0]}")
         out[name] = {"columns": list(cols),
-                     "rows": [[_value(r[c], f"{name} row {i} {c}") for c in cols] for i, r in enumerate(rows)]}
+                     "rows": [[_value(r[c] if c in r else defaults[c], f"{name} row {i} {c}") for c in cols]
+                              for i, r in enumerate(rows)]}
     return out
 
 
diff --git a/tests/test_deckdata.py b/tests/test_deckdata.py
index da68109..fbd39a2 100644
--- a/tests/test_deckdata.py
+++ b/tests/test_deckdata.py
@@ -214,6 +214,22 @@ def rows(name):
     assert document["provenance"]["tables"]["MasterVip"] == hashlib.sha256((tmp_path / "m/MasterVip.bin").read_bytes()).hexdigest()
 
 
+def test_character_non_playable_flag(tmp_path):
+    def rows(name):
+        if name == "MasterCharacter":
+            return [
+                {"_id": 1, "_bandID": 1, "_isNonPlayable": True},
+                {"_id": 2, "_bandID": 2, "_isNonPlayable": False},
+                {"_id": 3, "_bandID": 1},  # a master without the column
+            ]
+        return rows_of(name)
+
+    export(tmp_path, rows=rows)
+    raw = (tmp_path / "deck.json").read_bytes()
+    expected = '"MasterCharacter":{"columns":["_id","_bandID","_isNonPlayable"],"rows":[[1,1,true],[2,2,false],[3,1,false]]}'
+    assert expected.encode() in raw
+
+
 def test_character_rank_carries_its_experience_threshold(tmp_path):
     def rows(name):
         if name == "MasterCharacterRank":