diff --git a/include/config.h b/include/config.h
index 9a1f5d8d..1faf0b89 100644
--- a/include/config.h
+++ b/include/config.h
@@ -29,6 +29,7 @@ public:
     void save();
     void load();
     void setSaveDisabled(bool disabled);
+    void logInvalidKey(const QString &key);
     virtual ~KeyValueConfigBase();
     virtual void reset() = 0;
 protected:
@@ -319,6 +320,8 @@ public:
         this->blockCollisionMask = 0x0C00;
         this->blockElevationMask = 0xF000;
         this->identifiers.clear();
+        this->defaultEventCustomAttributes.clear();
+        this->defaultMapCustomAttributes.clear();
         this->readKeys.clear();
     }
     static const QMap<ProjectIdentifier, QPair<QString, QString>> defaultIdentifiers;
@@ -417,6 +420,12 @@ public:
     int getCollisionSheetHeight();
     void setWarpBehaviors(const QSet<uint32_t> &behaviors);
     QSet<uint32_t> getWarpBehaviors();
+    void insertDefaultEventCustomAttribute(Event::Type eventType, const QString &key, QJsonValue value);
+    void insertDefaultMapCustomAttribute(const QString &key, QJsonValue value);
+    void removeDefaultEventCustomAttribute(Event::Type eventType, const QString &key);
+    void removeDefaultMapCustomAttribute(const QString &key);
+    QMap<QString, QJsonValue> getDefaultEventCustomAttributes(Event::Type eventType);
+    QMap<QString, QJsonValue> getDefaultMapCustomAttributes();
 
 protected:
     virtual QString getConfigFilepath() override;
@@ -425,6 +434,9 @@ protected:
     virtual void onNewConfigFileCreated() override;
     virtual void setUnreadKeys() override;
 private:
+    void parseCustomAttributes(const QString &key, const QString &value);
+    QString customAttributesToString(const QMap<QString, QJsonValue> attributes);
+
     BaseGameVersion baseGameVersion;
     QString projectDir;
     QMap<ProjectIdentifier, QString> identifiers;
@@ -466,6 +478,8 @@ private:
     int collisionSheetWidth;
     int collisionSheetHeight;
     QSet<uint32_t> warpBehaviors;
+    QMap<Event::Type, QMap<QString, QJsonValue>> defaultEventCustomAttributes;
+    QMap<QString, QJsonValue> defaultMapCustomAttributes;
 };
 
 extern ProjectConfig projectConfig;
diff --git a/include/core/events.h b/include/core/events.h
index 8be1bbfc..681f11aa 100644
--- a/include/core/events.h
+++ b/include/core/events.h
@@ -158,10 +158,11 @@ public:
     virtual void setDefaultValues(Project *project);
 
     virtual QSet<QString> getExpectedFields() = 0;
-    void readCustomValues(QJsonObject values);
-    void addCustomValuesTo(OrderedJson::object *obj);
-    const QMap<QString, QJsonValue> getCustomValues() { return this->customValues; }
-    void setCustomValues(const QMap<QString, QJsonValue> newCustomValues) { this->customValues = newCustomValues; }
+    void readCustomAttributes(QJsonObject values);
+    void addCustomAttributesTo(OrderedJson::object *obj);
+    const QMap<QString, QJsonValue> getCustomAttributes() { return this->customAttributes; }
+    void setCustomAttributes(const QMap<QString, QJsonValue> newCustomAttributes) { this->customAttributes = newCustomAttributes; }
+    void setDefaultCustomAttributes();
 
     virtual void loadPixmap(Project *project);
 
@@ -203,7 +204,7 @@ protected:
     int spriteHeight = 16;
     bool usingSprite = false;
 
-    QMap<QString, QJsonValue> customValues;
+    QMap<QString, QJsonValue> customAttributes;
 
     QPixmap pixmap;
     DraggablePixmapItem *pixmapItem = nullptr;
diff --git a/include/mainwindow.h b/include/mainwindow.h
index 352e6ccf..827eafaa 100644
--- a/include/mainwindow.h
+++ b/include/mainwindow.h
@@ -379,7 +379,7 @@ private:
     Event::Group getEventGroupFromTabWidget(QWidget *tab);
     void closeSupplementaryWindows();
     void setWindowDisabled(bool);
-
+    void resetMapCustomAttributesTable();
     void initTilesetEditor();
     bool initRegionMapEditor(bool silent = false);
     void initShortcutsEditor();
diff --git a/include/ui/customattributesdialog.h b/include/ui/customattributesdialog.h
index 749a6691..33dea972 100644
--- a/include/ui/customattributesdialog.h
+++ b/include/ui/customattributesdialog.h
@@ -23,7 +23,8 @@ private:
     CustomAttributesTable *const table;
 
     void addNewAttribute();
-    bool verifyName();
+    bool verifyInput();
+    QVariant getValue() const;
     void setNameEditHighlight(bool highlight);
 };
 
diff --git a/include/ui/customattributestable.h b/include/ui/customattributestable.h
index 425b5f1f..629597cc 100644
--- a/include/ui/customattributestable.h
+++ b/include/ui/customattributestable.h
@@ -16,27 +16,31 @@ public:
 
     QMap<QString, QJsonValue> getAttributes() const;
     void setAttributes(const QMap<QString, QJsonValue> attributes);
-    void addNewAttribute(const QString &key, QJsonValue value);
-
-    void setDefaultAttribute(const QString &key, QJsonValue value);
-    void unsetDefaultAttribute(const QString &key);
+    void addNewAttribute(const QString &key, QJsonValue value, bool setAsDefault);
 
     QSet<QString> keys() const;
+    QSet<QString> defaultKeys() const;
     QSet<QString> restrictedKeys() const;
+    void setDefaultKeys(const QSet<QString> keys);
     void setRestrictedKeys(const QSet<QString> keys);
 
 signals:
     void edited();
+    void defaultSet(QString key, QJsonValue value);
+    void defaultRemoved(QString key);
 
 private:
     QTableWidget *table;
 
-    QSet<QString> m_keys;
-    QSet<QString> m_restrictedKeys;
+    QSet<QString> m_keys;           // All keys currently in the table
+    QSet<QString> m_defaultKeys;    // All keys that are in this table by default (whether or not they're present)
+    QSet<QString> m_restrictedKeys; // All keys not allowed in the table
 
     int addAttribute(const QString &key, QJsonValue value);
     void removeAttribute(const QString &key);
     bool deleteSelectedAttributes();
+    void setDefaultAttribute(const QString &key, QJsonValue value);
+    void unsetDefaultAttribute(const QString &key);
     void resizeVertically();
 };
 
diff --git a/src/config.cpp b/src/config.cpp
index 2dba96e4..2d8c4ede 100644
--- a/src/config.cpp
+++ b/src/config.cpp
@@ -292,6 +292,10 @@ void KeyValueConfigBase::setSaveDisabled(bool disabled) {
     this->saveDisabled = disabled;
 }
 
+void KeyValueConfigBase::logInvalidKey(const QString &key) {
+    logWarn(QString("Invalid config key found in config file %1: '%2'").arg(this->getConfigFilepath()).arg(key));
+}
+
 const QMap<MapSortOrder, QString> mapSortOrderMap = {
     {MapSortOrder::Group, "group"},
     {MapSortOrder::Layout, "layout"},
@@ -400,7 +404,7 @@ void PorymapConfig::parseConfigKeyValue(QString key, QString value) {
     } else if (key == "warp_behavior_warning_disabled") {
         this->warpBehaviorWarningDisabled = getConfigBool(key, value);
     } else {
-        logWarn(QString("Invalid config key found in config file %1: '%2'").arg(this->getConfigFilepath()).arg(key));
+        logInvalidKey(key);
     }
 }
 
@@ -872,14 +876,14 @@ void ProjectConfig::parseConfigKeyValue(QString key, QString value) {
         if (k != static_cast<ProjectFilePath>(-1)) {
             this->setFilePath(k, value);
         } else {
-            logWarn(QString("Invalid config key found in config file %1: '%2'").arg(this->getConfigFilepath()).arg(key));
+            logInvalidKey(key);
         }
     } else if (key.startsWith("ident/")) {
         auto identifierId = reverseDefaultIdentifier(key.mid(6));
         if (identifierId != static_cast<ProjectIdentifier>(-1)) {
             this->setIdentifier(identifierId, value);
         } else {
-            logWarn(QString("Invalid config key found in config file %1: '%2'").arg(this->getConfigFilepath()).arg(key));
+            logInvalidKey(key);
         }
     } else if (key == "prefabs_filepath") {
         this->prefabFilepath = value;
@@ -913,8 +917,10 @@ void ProjectConfig::parseConfigKeyValue(QString key, QString value) {
         QStringList behaviorList = value.split(",", Qt::SkipEmptyParts);
         for (auto s : behaviorList)
             this->warpBehaviors.insert(getConfigUint32(key, s));
+    } else if (key.startsWith("custom_attributes/")) {
+        this->parseCustomAttributes(key, value);
     } else {
-        logWarn(QString("Invalid config key found in config file %1: '%2'").arg(this->getConfigFilepath()).arg(key));
+        logInvalidKey(key);
     }
     readKeys.append(key);
 }
@@ -1004,6 +1010,12 @@ QMap<QString, QString> ProjectConfig::getKeyValueMap() {
     for (auto value : this->warpBehaviors)
         warpBehaviorStrs.append("0x" + QString("%1").arg(value, 2, 16, QChar('0')).toUpper());
     map.insert("warp_behaviors", warpBehaviorStrs.join(","));
+    if (!this->defaultMapCustomAttributes.isEmpty())
+        map.insert("custom_attributes/header", this->customAttributesToString(this->defaultMapCustomAttributes));
+    for (auto i = this->defaultEventCustomAttributes.cbegin(), end = this->defaultEventCustomAttributes.cend(); i != end; i++) {
+        if (!i.value().isEmpty())
+            map.insert("custom_attributes/" + Event::eventTypeToString(i.key()), this->customAttributesToString(i.value()));
+    }
 
     return map;
 }
@@ -1466,6 +1478,123 @@ QSet<uint32_t> ProjectConfig::getWarpBehaviors() {
     return this->warpBehaviors;
 }
 
+void ProjectConfig::insertDefaultEventCustomAttribute(Event::Type eventType, const QString &key, QJsonValue value) {
+    this->defaultEventCustomAttributes[eventType].insert(key, value);
+    this->save();
+}
+
+void ProjectConfig::insertDefaultMapCustomAttribute(const QString &key, QJsonValue value) {
+    this->defaultMapCustomAttributes.insert(key, value);
+    this->save();
+}
+
+void ProjectConfig::removeDefaultEventCustomAttribute(Event::Type eventType, const QString &key) {
+    this->defaultEventCustomAttributes[eventType].remove(key);
+    this->save();
+}
+
+void ProjectConfig::removeDefaultMapCustomAttribute(const QString &key) {
+    this->defaultMapCustomAttributes.remove(key);
+    this->save();
+}
+
+QMap<QString, QJsonValue> ProjectConfig::getDefaultEventCustomAttributes(Event::Type eventType) {
+    return this->defaultEventCustomAttributes.value(eventType);
+}
+
+QMap<QString, QJsonValue> ProjectConfig::getDefaultMapCustomAttributes() {
+    return this->defaultMapCustomAttributes;
+}
+
+void ProjectConfig::parseCustomAttributes(const QString &key, const QString &value) {
+    static const QRegularExpression regex("custom_attributes/(?<identifier>\\w+)");
+    auto match = regex.match(key);
+    if (!match.hasMatch()){
+        logInvalidKey(key);
+        return;
+    }
+
+    // Value should be a comma-separated list of sequences of the form 'key:type:value'.
+    // Some day if this config file is formatted as JSON data we wouldn't need to store 'type' (among other simplifications).
+    QMap<QString, QJsonValue> map;
+    const QStringList attributeSequences = value.split(",", Qt::SkipEmptyParts);
+    if (attributeSequences.isEmpty())
+        return;
+    for (auto sequence : attributeSequences) {
+        // Parse each 'type:key:value' sequence
+        const QStringList attributeData = sequence.split(":");
+        if (attributeData.length() != 3) {
+            logWarn(QString("Invalid value '%1' for custom attribute in '%2'").arg(sequence).arg(key));
+            continue;
+        }
+        const QString attrKey = attributeData.at(0);
+        const QString attrType = attributeData.at(1);
+        const QString attrValue = attributeData.at(2);
+
+        QJsonValue value;
+        if (attrType == "string") {
+            value = QJsonValue(attrValue);
+        } else if (attrType == "number") {
+            bool ok;
+            int num = attrValue.toInt(&ok, 0);
+            if (!ok)
+                logWarn(QString("Invalid value '%1' for custom attribute '%2' in '%3'").arg(attrValue).arg(attrKey).arg(key));
+            value = QJsonValue(num);
+        } else if (attrType == "bool") {
+            bool ok;
+            int num = attrValue.toInt(&ok, 0);
+            if (!ok || (num != 0 && num != 1))
+                logWarn(QString("Invalid value '%1' for custom attribute '%2' in '%3'").arg(attrValue).arg(attrKey).arg(key));
+            value = QJsonValue(num == 1);
+        } else {
+            logWarn(QString("Invalid value type '%1' for custom attribute '%2' in '%3'").arg(attrType).arg(attrKey).arg(key));
+            continue;
+        }
+        // Successfully parsed a 'type:key:value' sequence
+        map.insert(attrKey, value);
+    }
+
+    // Determine who the custom attribute map belongs to (either the map header or some Event type)
+    const QString identifier = match.captured("identifier");
+
+    if (identifier == "header") {
+        this->defaultMapCustomAttributes = map;
+        return;
+    }
+
+    Event::Type eventType = Event::eventTypeFromString(identifier);
+    if (eventType != Event::Type::None) {
+        this->defaultEventCustomAttributes[eventType] = map;
+        return;
+    }
+
+    logWarn(QString("Invalid custom attributes identifier '%1' in '%2'").arg(identifier).arg(key));
+}
+
+// Assemble comma-separated list of sequences of the form 'key:type:value'.
+QString ProjectConfig::customAttributesToString(const QMap<QString, QJsonValue> attributes) {
+    QStringList output;
+    for (auto i = attributes.cbegin(), end = attributes.cend(); i != end; i++) {
+        QString value;
+        QString typeStr;
+        QJsonValue::Type type = i.value().type();
+        if (type == QJsonValue::Type::String) {
+            typeStr = "string";
+            value = i.value().toString();
+        } else if (type == QJsonValue::Type::Double) {
+            typeStr = "number";
+            value = QString::number(i.value().toInt());
+        } else if (type == QJsonValue::Type::Bool) {
+            typeStr = "bool";
+            value = QString::number(i.value().toBool());
+        } else {
+            continue;
+        }
+        output.append(QString("%1:%2:%3").arg(i.key()).arg(typeStr).arg(value));
+    }
+    return output.join(",");
+}
+
 
 UserConfig userConfig;
 
@@ -1482,7 +1611,7 @@ void UserConfig::parseConfigKeyValue(QString key, QString value) {
     } else if (key == "custom_scripts") {
         this->parseCustomScripts(value);
     } else {
-        logWarn(QString("Invalid config key found in config file %1: '%2'").arg(this->getConfigFilepath()).arg(key));
+        logInvalidKey(key);
     }
     readKeys.append(key);
 }
diff --git a/src/core/events.cpp b/src/core/events.cpp
index 1b9605fb..c0b7f3f6 100644
--- a/src/core/events.cpp
+++ b/src/core/events.cpp
@@ -36,22 +36,27 @@ void Event::setDefaultValues(Project *) {
     this->setX(0);
     this->setY(0);
     this->setElevation(projectConfig.getDefaultElevation());
+    this->setDefaultCustomAttributes();
 }
 
-void Event::readCustomValues(QJsonObject values) {
-    this->customValues.clear();
+void Event::setDefaultCustomAttributes() {
+    this->setCustomAttributes(projectConfig.getDefaultEventCustomAttributes(this->getEventType()));
+}
+
+void Event::readCustomAttributes(QJsonObject values) {
+    this->customAttributes.clear();
     QSet<QString> expectedFields = this->getExpectedFields();
     for (QString key : values.keys()) {
         if (!expectedFields.contains(key)) {
-            this->customValues[key] = values[key];
+            this->customAttributes[key] = values[key];
         }
     }
 }
 
-void Event::addCustomValuesTo(OrderedJson::object *obj) {
-    for (QString key : this->customValues.keys()) {
+void Event::addCustomAttributesTo(OrderedJson::object *obj) {
+    for (QString key : this->customAttributes.keys()) {
         if (!obj->contains(key)) {
-            (*obj)[key] = OrderedJson::fromQJsonValue(this->customValues[key]);
+            (*obj)[key] = OrderedJson::fromQJsonValue(this->customAttributes[key]);
         }
     }
 }
@@ -179,7 +184,7 @@ Event *ObjectEvent::duplicate() {
     copy->setSightRadiusBerryTreeID(this->getSightRadiusBerryTreeID());
     copy->setScript(this->getScript());
     copy->setFlag(this->getFlag());
-    copy->setCustomValues(this->getCustomValues());
+    copy->setCustomAttributes(this->getCustomAttributes());
 
     return copy;
 }
@@ -209,7 +214,7 @@ OrderedJson::object ObjectEvent::buildEventJson(Project *) {
     objectJson["trainer_sight_or_berry_tree_id"] = this->getSightRadiusBerryTreeID();
     objectJson["script"] = this->getScript();
     objectJson["flag"] = this->getFlag();
-    this->addCustomValuesTo(&objectJson);
+    this->addCustomAttributesTo(&objectJson);
 
     return objectJson;
 }
@@ -227,7 +232,7 @@ bool ObjectEvent::loadFromJson(QJsonObject json, Project *) {
     this->setScript(ParseUtil::jsonToQString(json["script"]));
     this->setFlag(ParseUtil::jsonToQString(json["flag"]));
     
-    this->readCustomValues(json);
+    this->readCustomAttributes(json);
 
     return true;
 }
@@ -242,6 +247,7 @@ void ObjectEvent::setDefaultValues(Project *project) {
     this->setRadiusY(0);
     this->setSightRadiusBerryTreeID("0");
     this->setFrameFromMovement(project->facingDirections.value(this->getMovement()));
+    this->setDefaultCustomAttributes();
 }
 
 const QSet<QString> expectedObjectFields = {
@@ -353,7 +359,7 @@ Event *CloneObjectEvent::duplicate() {
     copy->setGfx(this->getGfx());
     copy->setTargetID(this->getTargetID());
     copy->setTargetMap(this->getTargetMap());
-    copy->setCustomValues(this->getCustomValues());
+    copy->setCustomAttributes(this->getCustomAttributes());
 
     return copy;
 }
@@ -375,7 +381,7 @@ OrderedJson::object CloneObjectEvent::buildEventJson(Project *project) {
     cloneJson["y"] = this->getY();
     cloneJson["target_local_id"] = this->getTargetID();
     cloneJson["target_map"] = project->mapNamesToMapConstants.value(this->getTargetMap());
-    this->addCustomValuesTo(&cloneJson);
+    this->addCustomAttributesTo(&cloneJson);
 
     return cloneJson;
 }
@@ -398,7 +404,7 @@ bool CloneObjectEvent::loadFromJson(QJsonObject json, Project *project) {
         this->setTargetMap(DYNAMIC_MAP_NAME);
     }
 
-    this->readCustomValues(json);
+    this->readCustomAttributes(json);
 
     return true;
 }
@@ -407,6 +413,7 @@ void CloneObjectEvent::setDefaultValues(Project *project) {
     this->setGfx(project->gfxDefines.keys().first());
     this->setTargetID(1);
     if (this->getMap()) this->setTargetMap(this->getMap()->name);
+    this->setDefaultCustomAttributes();
 }
 
 const QSet<QString> expectedCloneObjectFields = {
@@ -465,7 +472,7 @@ Event *WarpEvent::duplicate() {
     copy->setDestinationMap(this->getDestinationMap());
     copy->setDestinationWarpID(this->getDestinationWarpID());
 
-    copy->setCustomValues(this->getCustomValues());
+    copy->setCustomAttributes(this->getCustomAttributes());
 
     return copy;
 }
@@ -487,7 +494,7 @@ OrderedJson::object WarpEvent::buildEventJson(Project *project) {
     warpJson["dest_map"] = project->mapNamesToMapConstants.value(this->getDestinationMap());
     warpJson["dest_warp_id"] = this->getDestinationWarpID();
 
-    this->addCustomValuesTo(&warpJson);
+    this->addCustomAttributesTo(&warpJson);
 
     return warpJson;
 }
@@ -510,7 +517,7 @@ bool WarpEvent::loadFromJson(QJsonObject json, Project *project) {
         this->setDestinationMap(DYNAMIC_MAP_NAME);
     }
 
-    this->readCustomValues(json);
+    this->readCustomAttributes(json);
 
     return true;
 }
@@ -519,6 +526,7 @@ void WarpEvent::setDefaultValues(Project *) {
     if (this->getMap()) this->setDestinationMap(this->getMap()->name);
     this->setDestinationWarpID("0");
     this->setElevation(0);
+    this->setDefaultCustomAttributes();
 }
 
 const QSet<QString> expectedWarpFields = {
@@ -552,7 +560,7 @@ Event *TriggerEvent::duplicate() {
     copy->setScriptVarValue(this->getScriptVarValue());
     copy->setScriptLabel(this->getScriptLabel());
 
-    copy->setCustomValues(this->getCustomValues());
+    copy->setCustomAttributes(this->getCustomAttributes());
 
     return copy;
 }
@@ -576,7 +584,7 @@ OrderedJson::object TriggerEvent::buildEventJson(Project *) {
     triggerJson["var_value"] = this->getScriptVarValue();
     triggerJson["script"] = this->getScriptLabel();
 
-    this->addCustomValuesTo(&triggerJson);
+    this->addCustomAttributesTo(&triggerJson);
 
     return triggerJson;
 }
@@ -589,7 +597,7 @@ bool TriggerEvent::loadFromJson(QJsonObject json, Project *) {
     this->setScriptVarValue(ParseUtil::jsonToQString(json["var_value"]));
     this->setScriptLabel(ParseUtil::jsonToQString(json["script"]));
 
-    this->readCustomValues(json);
+    this->readCustomAttributes(json);
 
     return true;
 }
@@ -599,6 +607,7 @@ void TriggerEvent::setDefaultValues(Project *project) {
     this->setScriptVar(project->varNames.first());
     this->setScriptVarValue("0");
     this->setElevation(0);
+    this->setDefaultCustomAttributes();
 }
 
 const QSet<QString> expectedTriggerFields = {
@@ -626,7 +635,7 @@ Event *WeatherTriggerEvent::duplicate() {
     copy->setElevation(this->getElevation());
     copy->setWeather(this->getWeather());
 
-    copy->setCustomValues(this->getCustomValues());
+    copy->setCustomAttributes(this->getCustomAttributes());
 
     return copy;
 }
@@ -648,7 +657,7 @@ OrderedJson::object WeatherTriggerEvent::buildEventJson(Project *) {
     weatherJson["elevation"] = this->getElevation();
     weatherJson["weather"] = this->getWeather();
 
-    this->addCustomValuesTo(&weatherJson);
+    this->addCustomAttributesTo(&weatherJson);
 
     return weatherJson;
 }
@@ -659,7 +668,7 @@ bool WeatherTriggerEvent::loadFromJson(QJsonObject json, Project *) {
     this->setElevation(ParseUtil::jsonToInt(json["elevation"]));
     this->setWeather(ParseUtil::jsonToQString(json["weather"]));
 
-    this->readCustomValues(json);
+    this->readCustomAttributes(json);
 
     return true;
 }
@@ -667,6 +676,7 @@ bool WeatherTriggerEvent::loadFromJson(QJsonObject json, Project *) {
 void WeatherTriggerEvent::setDefaultValues(Project *project) {
     this->setWeather(project->coordEventWeatherNames.first());
     this->setElevation(0);
+    this->setDefaultCustomAttributes();
 }
 
 const QSet<QString> expectedWeatherTriggerFields = {
@@ -693,7 +703,7 @@ Event *SignEvent::duplicate() {
     copy->setFacingDirection(this->getFacingDirection());
     copy->setScriptLabel(this->getScriptLabel());
 
-    copy->setCustomValues(this->getCustomValues());
+    copy->setCustomAttributes(this->getCustomAttributes());
 
     return copy;
 }
@@ -716,7 +726,7 @@ OrderedJson::object SignEvent::buildEventJson(Project *) {
     signJson["player_facing_dir"] = this->getFacingDirection();
     signJson["script"] = this->getScriptLabel();
 
-    this->addCustomValuesTo(&signJson);
+    this->addCustomAttributesTo(&signJson);
 
     return signJson;
 }
@@ -728,7 +738,7 @@ bool SignEvent::loadFromJson(QJsonObject json, Project *) {
     this->setFacingDirection(ParseUtil::jsonToQString(json["player_facing_dir"]));
     this->setScriptLabel(ParseUtil::jsonToQString(json["script"]));
 
-    this->readCustomValues(json);
+    this->readCustomAttributes(json);
 
     return true;
 }
@@ -737,6 +747,7 @@ void SignEvent::setDefaultValues(Project *project) {
     this->setFacingDirection(project->bgEventFacingDirections.first());
     this->setScriptLabel("NULL");
     this->setElevation(0);
+    this->setDefaultCustomAttributes();
 }
 
 const QSet<QString> expectedSignFields = {
@@ -766,7 +777,7 @@ Event *HiddenItemEvent::duplicate() {
     copy->setQuantity(this->getQuantity());
     copy->setQuantity(this->getQuantity());
 
-    copy->setCustomValues(this->getCustomValues());
+    copy->setCustomAttributes(this->getCustomAttributes());
 
     return copy;
 }
@@ -795,7 +806,7 @@ OrderedJson::object HiddenItemEvent::buildEventJson(Project *) {
         hiddenItemJson["underfoot"] = this->getUnderfoot();
     }
 
-    this->addCustomValuesTo(&hiddenItemJson);
+    this->addCustomAttributesTo(&hiddenItemJson);
 
     return hiddenItemJson;
 }
@@ -813,7 +824,7 @@ bool HiddenItemEvent::loadFromJson(QJsonObject json, Project *) {
         this->setUnderfoot(ParseUtil::jsonToBool(json["underfoot"]));
     }
 
-    this->readCustomValues(json);
+    this->readCustomAttributes(json);
 
     return true;
 }
@@ -827,6 +838,7 @@ void HiddenItemEvent::setDefaultValues(Project *project) {
     if (projectConfig.getHiddenItemRequiresItemfinderEnabled()) {
         this->setUnderfoot(false);
     }
+    this->setDefaultCustomAttributes();
 }
 
 const QSet<QString> expectedHiddenItemFields = {
@@ -859,7 +871,7 @@ Event *SecretBaseEvent::duplicate() {
     copy->setElevation(this->getElevation());
     copy->setBaseID(this->getBaseID());
 
-    copy->setCustomValues(this->getCustomValues());
+    copy->setCustomAttributes(this->getCustomAttributes());
 
     return copy;
 }
@@ -881,7 +893,7 @@ OrderedJson::object SecretBaseEvent::buildEventJson(Project *) {
     secretBaseJson["elevation"] = this->getElevation();
     secretBaseJson["secret_base_id"] = this->getBaseID();
 
-    this->addCustomValuesTo(&secretBaseJson);
+    this->addCustomAttributesTo(&secretBaseJson);
 
     return secretBaseJson;
 }
@@ -892,7 +904,7 @@ bool SecretBaseEvent::loadFromJson(QJsonObject json, Project *) {
     this->setElevation(ParseUtil::jsonToInt(json["elevation"]));
     this->setBaseID(ParseUtil::jsonToQString(json["secret_base_id"]));
 
-    this->readCustomValues(json);
+    this->readCustomAttributes(json);
 
     return true;
 }
@@ -900,6 +912,7 @@ bool SecretBaseEvent::loadFromJson(QJsonObject json, Project *) {
 void SecretBaseEvent::setDefaultValues(Project *project) {
     this->setBaseID(project->secretBaseIds.first());
     this->setElevation(0);
+    this->setDefaultCustomAttributes();
 }
 
 const QSet<QString> expectedSecretBaseFields = {
@@ -931,6 +944,7 @@ OrderedJson::object HealLocationEvent::buildEventJson(Project *) {
 
 void HealLocationEvent::setDefaultValues(Project *) {
     this->setElevation(projectConfig.getDefaultElevation());
+    this->setDefaultCustomAttributes();
     if (!this->getMap())
         return;
     bool respawnEnabled = projectConfig.getHealLocationRespawnDataEnabled();
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index 84200198..e2f29b2d 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -302,10 +302,23 @@ void MainWindow::initEditor() {
         this->editor->selectedEventIndexChanged(value, Event::Group::Heal);
     });
 
+    // Connect the Custom Attributes table on the Header tab
     connect(ui->mapCustomAttributesTable, &CustomAttributesTable::edited, [this]() {
         this->markMapEdited();
         this->editor->updateCustomMapHeaderValues();
     });
+    connect(ui->mapCustomAttributesTable, &CustomAttributesTable::defaultSet, [](QString key, QJsonValue value) {
+        projectConfig.insertDefaultMapCustomAttribute(key, value);
+    });
+    connect(ui->mapCustomAttributesTable, &CustomAttributesTable::defaultRemoved, [](QString key) {
+        projectConfig.removeDefaultMapCustomAttribute(key);
+    });
+}
+
+void MainWindow::resetMapCustomAttributesTable() {
+    QStringList keys = projectConfig.getDefaultMapCustomAttributes().keys();
+    ui->mapCustomAttributesTable->setDefaultKeys(QSet<QString>(keys.begin(), keys.end()));
+    ui->mapCustomAttributesTable->setRestrictedKeys(Project::getTopLevelMapFields());
 }
 
 void MainWindow::initMiscHeapObjects() {
@@ -512,8 +525,8 @@ bool MainWindow::openProject(const QString &dir, bool initial) {
     projectConfig.load();
 
     this->closeSupplementaryWindows();
+    this->resetMapCustomAttributesTable();
     this->newMapDefaultsSet = false;
-    ui->mapCustomAttributesTable->setRestrictedKeys(Project::getTopLevelMapFields());
 
     if (isProjectOpen())
         Scripting::cb_ProjectClosed(editor->project->root);
diff --git a/src/ui/customattributesdialog.cpp b/src/ui/customattributesdialog.cpp
index d7845b62..2bc87e56 100644
--- a/src/ui/customattributesdialog.cpp
+++ b/src/ui/customattributesdialog.cpp
@@ -31,16 +31,23 @@ CustomAttributesDialog::CustomAttributesDialog(CustomAttributesTable *parent) :
         this->setNameEditHighlight(false);
     });
 
+    // Exclude delimiters used in the config
+    static const QRegularExpression expression("[^:,=/]*");
+    ui->lineEdit_Name->setValidator(new QRegularExpressionValidator(expression));
+
     // Button box
     connect(ui->buttonBox, &QDialogButtonBox::clicked, [this](QAbstractButton *button) {
         auto buttonRole = ui->buttonBox->buttonRole(button);
-        if (buttonRole == QDialogButtonBox::AcceptRole && this->verifyName()) {
+        if (buttonRole == QDialogButtonBox::AcceptRole && this->verifyInput()) {
             this->addNewAttribute();
             this->done(QDialog::Accepted);
         } else if (buttonRole == QDialogButtonBox::RejectRole) {
             this->done(QDialog::Rejected);
         }
     });
+
+    ui->spinBox_Value->setMinimum(INT_MIN);
+    ui->spinBox_Value->setMaximum(INT_MAX);
 }
 
 CustomAttributesDialog::~CustomAttributesDialog() {
@@ -51,7 +58,7 @@ void CustomAttributesDialog::setNameEditHighlight(bool highlight) {
     ui->lineEdit_Name->setStyleSheet(highlight ? "QLineEdit { background-color: rgba(255, 0, 0, 25%) }" : "");
 }
 
-bool CustomAttributesDialog::verifyName() {
+bool CustomAttributesDialog::verifyInput() {
     const QString name = ui->lineEdit_Name->text();
 
     if (name.isEmpty()) {
@@ -67,8 +74,16 @@ bool CustomAttributesDialog::verifyName() {
         return false;
     }
 
+    // Warn user if changing the default value of a "Default" custom attribute
+    if (this->table->defaultKeys().contains(name) && ui->checkBox_Default->isChecked()) {
+        const QString msg = QString("'%1' is already a default attribute. Replace its default value with '%2'?")
+                                    .arg(name)
+                                    .arg(this->getValue().toString());
+        if (QMessageBox::warning(this, "Warning", msg, QMessageBox::Yes | QMessageBox::Cancel) == QMessageBox::Cancel)
+            return false;
+    }
     // Warn user if key name would overwrite an existing custom attribute
-    if (this->table->keys().contains(name)) {
+    else if (this->table->keys().contains(name)) {
         const QString msg = QString("Overwrite value for existing attribute '%1'?").arg(name);
         if (QMessageBox::warning(this, "Warning", msg, QMessageBox::Yes | QMessageBox::Cancel) == QMessageBox::Cancel)
             return false;
@@ -77,20 +92,19 @@ bool CustomAttributesDialog::verifyName() {
     return true;
 }
 
-void CustomAttributesDialog::addNewAttribute() {
-    QJsonValue value;
+QVariant CustomAttributesDialog::getValue() const {
+    QVariant value;
     const QString type = ui->comboBox_Type->currentText();
     if (type == "String") {
-        value = QJsonValue(ui->lineEdit_Value->text());
+        value = QVariant(ui->lineEdit_Value->text());
     } else if (type == "Number") {
-        value = QJsonValue(ui->spinBox_Value->value());
+        value = QVariant(ui->spinBox_Value->value());
     } else if (type == "Boolean") {
-        value = QJsonValue(ui->checkBox_Value->isChecked());
+        value = QVariant(ui->checkBox_Value->isChecked());
     }
-
-    const QString key = ui->lineEdit_Name->text();
-    this->table->addNewAttribute(key, value);
-
-    if (ui->checkBox_Default->isChecked())
-        this->table->setDefaultAttribute(key, value);
+    return value;
+}
+
+void CustomAttributesDialog::addNewAttribute() {
+    this->table->addNewAttribute(ui->lineEdit_Name->text(), QJsonValue::fromVariant(this->getValue()), ui->checkBox_Default->isChecked());
 }
diff --git a/src/ui/customattributestable.cpp b/src/ui/customattributestable.cpp
index bc4dea2b..7f08471e 100644
--- a/src/ui/customattributestable.cpp
+++ b/src/ui/customattributestable.cpp
@@ -15,14 +15,11 @@ enum Column {
     Count
 };
 
-// TODO: Tooltip-- "Custom fields will be added to the map.json file for the current map."?
-// TODO: Fix squishing when first element is added
-// TODO: Fix Header table size on first open
-// TODO: Take control of Delete key?
-// TODO: Edit history?
 CustomAttributesTable::CustomAttributesTable(QWidget *parent) :
     QFrame(parent)
 {
+    this->setAttribute(Qt::WA_DeleteOnClose);
+
     QVBoxLayout *layout = new QVBoxLayout(this);
     QLabel *label = new QLabel("Custom Attributes");
     layout->addWidget(label);
@@ -72,9 +69,19 @@ CustomAttributesTable::CustomAttributesTable(QWidget *parent) :
     // Adding the "Selectable" flag to the Key cell changes its appearance to match the Value cell, which
     // makes it confusing that you can't edit the Key cell. To keep the uneditable appearance and allow
     // deleting rows by selecting Key cells, we select the full row when a Key cell is selected.
+    // Double clicking the Key cell will begin editing the value cell, as it would for double-clicking the value cell.
     connect(this->table, &QTableWidget::cellClicked, [this](int row, int column) {
-        if (column == Column::Key) this->table->selectRow(row);
+        if (column == Column::Key) {
+            this->table->selectRow(row);
+        }
     });
+    connect(this->table, &QTableWidget::cellDoubleClicked, [this](int row, int column) {
+        if (column == Column::Key) {
+            auto index = this->table->model()->index(row, Column::Value);
+            this->table->edit(index);
+        }
+    });
+    // TODO: Right-click for context menu to set a default?
 }
 
 CustomAttributesTable::~CustomAttributesTable()
@@ -142,7 +149,7 @@ int CustomAttributesTable::addAttribute(const QString &key, QJsonValue value) {
         return -1;
 
     // Overwrite existing key (if present)
-    if (this->m_keys.remove(key))
+    if (this->m_keys.contains(key))
         this->removeAttribute(key);
 
     // Add new row
@@ -170,6 +177,7 @@ int CustomAttributesTable::addAttribute(const QString &key, QJsonValue value) {
         spinBox->setMinimum(INT_MIN);
         spinBox->setMaximum(INT_MAX);
         spinBox->setValue(ParseUtil::jsonToInt(value));
+        // This connection will be handled by QTableWidget::cellChanged for other cell types
         connect(spinBox, QOverload<int>::of(&QSpinBox::valueChanged), [this]() { emit this->edited(); });
         this->table->setCellWidget(rowIndex, Column::Value, spinBox);
         break;
@@ -194,9 +202,10 @@ int CustomAttributesTable::addAttribute(const QString &key, QJsonValue value) {
 }
 
 // For the user adding an attribute by interacting with the table
-void CustomAttributesTable::addNewAttribute(const QString &key, QJsonValue value) {
+void CustomAttributesTable::addNewAttribute(const QString &key, QJsonValue value, bool setAsDefault) {
     int row = this->addAttribute(key, value);
     if (row < 0) return;
+    if (setAsDefault) this->setDefaultAttribute(key, value);
     this->table->selectRow(row);
     this->resizeVertically();
 }
@@ -210,21 +219,25 @@ void CustomAttributesTable::setAttributes(const QMap<QString, QJsonValue> attrib
 }
 
 void CustomAttributesTable::setDefaultAttribute(const QString &key, QJsonValue value) {
-    // TODO
+    m_defaultKeys.insert(key);
+    emit this->defaultSet(key, value);
 }
 
 void CustomAttributesTable::unsetDefaultAttribute(const QString &key) {
-    // TODO
+    if (m_defaultKeys.remove(key))
+        emit this->defaultRemoved(key);
 }
 
 void CustomAttributesTable::removeAttribute(const QString &key) {
     for (int row = 0; row < this->table->rowCount(); row++) {
         auto keyItem = this->table->item(row, Column::Key);
         if (keyItem && keyItem->text() == key) {
+            this->m_keys.remove(key);
             this->table->removeRow(row);
             break;
         }
     }
+    // No need to adjust size because this is (at the moment) only used for replacement
 }
 
 bool CustomAttributesTable::deleteSelectedAttributes() {
@@ -243,7 +256,10 @@ bool CustomAttributesTable::deleteSelectedAttributes() {
         return false;
 
     for (QPersistentModelIndex index : persistentIndexes) {
-        this->table->removeRow(index.row());
+        auto row = index.row();
+        auto item = this->table->item(row, Column::Key);
+        if (item) this->m_keys.remove(item->text());
+        this->table->removeRow(row);
     }
 
     if (this->table->rowCount() > 0) {
@@ -257,10 +273,18 @@ QSet<QString> CustomAttributesTable::keys() const {
     return this->m_keys;
 }
 
+QSet<QString> CustomAttributesTable::defaultKeys() const {
+    return this->m_defaultKeys;
+}
+
 QSet<QString> CustomAttributesTable::restrictedKeys() const {
     return this->m_restrictedKeys;
 }
 
+void CustomAttributesTable::setDefaultKeys(const QSet<QString> keys) {
+    this->m_defaultKeys = keys;
+}
+
 void CustomAttributesTable::setRestrictedKeys(const QSet<QString> keys) {
     this->m_restrictedKeys = keys;
 }
diff --git a/src/ui/eventframes.cpp b/src/ui/eventframes.cpp
index 08eb2ec5..2231d61f 100644
--- a/src/ui/eventframes.cpp
+++ b/src/ui/eventframes.cpp
@@ -103,8 +103,9 @@ void EventFrame::setup() {
 
 void EventFrame::initCustomAttributesTable() {
     this->custom_attributes = new CustomAttributesTable(this);
+    QStringList keys = projectConfig.getDefaultEventCustomAttributes(this->event->getEventType()).keys();
+    this->custom_attributes->setDefaultKeys(QSet<QString>(keys.begin(), keys.end()));
     this->custom_attributes->setRestrictedKeys(this->event->getExpectedFields());
-    this->custom_attributes->setAttributes(this->event->getCustomValues());
     this->layout_contents->addWidget(this->custom_attributes);
 }
 
@@ -138,9 +139,15 @@ void EventFrame::connectSignals(MainWindow *) {
 
     this->custom_attributes->disconnect();
     connect(this->custom_attributes, &CustomAttributesTable::edited, [this]() {
-        this->event->setCustomValues(this->custom_attributes->getAttributes());
+        this->event->setCustomAttributes(this->custom_attributes->getAttributes());
         this->event->modify();
     });
+    connect(this->custom_attributes, &CustomAttributesTable::defaultSet, [this](QString key, QJsonValue value) {
+        projectConfig.insertDefaultEventCustomAttribute(this->event->getEventType(), key, value);
+    });
+    connect(this->custom_attributes, &CustomAttributesTable::defaultRemoved, [this](QString key) {
+        projectConfig.removeDefaultEventCustomAttribute(this->event->getEventType(), key);
+    });
 }
 
 void EventFrame::initialize() {
@@ -152,6 +159,8 @@ void EventFrame::initialize() {
     this->spinner_y->setValue(this->event->getY());
     this->spinner_z->setValue(this->event->getZ());
 
+    this->custom_attributes->setAttributes(this->event->getCustomAttributes());
+
     this->label_icon->setPixmap(this->event->getPixmap());
 }
 
diff --git a/src/ui/newmappopup.cpp b/src/ui/newmappopup.cpp
index 0239b710..c7a3d0a9 100644
--- a/src/ui/newmappopup.cpp
+++ b/src/ui/newmappopup.cpp
@@ -303,6 +303,7 @@ void NewMapPopup::on_pushButton_NewMap_Accept_clicked() {
     if (projectConfig.getFloorNumberEnabled()) {
         newMap->floorNumber = this->ui->spinBox_NewMap_Floor_Number->value();
     }
+    newMap->customHeaders = projectConfig.getDefaultMapCustomAttributes();
 
     newMap->layout = layout;
     newMap->layoutId = layout->id;