[DeckEditor] Address custom-zone menu and export review feedback

Wires the state layer into every editor surface that shows deck zones.

- Deck dock: context menu on zones gains New/Rename/Delete/Change
  board actions, with per-zone submenus for adding cards.
- Card database dock and visual database display gain an add-to-zone
  submenu listing custom zones per board plus a create-zone entry.
- All prompt call sites pass validateNewZoneName so duplicates and
  reserved names are rejected inline before Ok unlocks.
- Rename reuses the same dialog in name-only mode, keeping one
  validation contract for every zone-name entry point.
- Change board marks the current board instead of offering a no-op,
  and the state layer refuses moves onto boards holding a same-named
  zone from imported decks.

cockatrice/CMakeLists.txt

@@ -214,6 +214,7 @@ set(cockatrice_SOURCES
     src/interface/widgets/deck_editor/deck_editor_printing_selector_dock_widget.cpp
     src/interface/widgets/deck_editor/deck_list_style_proxy.cpp
     src/interface/widgets/deck_editor/deck_state_manager.cpp
+    src/interface/widgets/deck_editor/deck_zone_dialog.cpp
     src/interface/widgets/deck_editor/printing_disabled_info_widget.cpp
     src/interface/widgets/general/background_sources.cpp
     src/interface/widgets/general/display/background_plate_widget.cpp

cockatrice/src/interface/deck_loader/deck_loader.cpp

@@ -384,6 +384,14 @@ void DeckLoader::saveToStream_DeckZone(QTextStream &out,
 
     for (int j = 0; j < zoneNode->size(); j++) {
         auto *card = dynamic_cast<DecklistCardNode *>(zoneNode->at(j));
+        if (!card) {
+            // Cards collected in nested sub-zones are exported by recursion so
+            // they don't end up invisible in the plain text output.
+            if (auto *subZone = dynamic_cast<const InnerDecklistNode *>(zoneNode->at(j))) {
+                saveToStream_DeckZone(out, subZone, addComments, addSetNameAndNumber);
+            }
+            continue;
+        }
 
         CardInfoPtr info = CardDatabaseManager::query()->getCardInfo(card->getName());
         QString cardType = info ? info->getMainCardType() : "unknown";
@@ -510,9 +518,26 @@ bool DeckLoader::convertToCockatriceFormat(LoadedDeck &deck)
 
 void DeckLoader::printDeckListNode(QTextCursor *cursor, const InnerDecklistNode *node)
 {
+    if (!node || node->isEmpty()) {
+        return;
+    }
+
     const int totalColumns = 2;
 
-    if (node->height() == 1) {
+    // Dispatch children by type instead of trusting a whole-node height: a deck
+    // node may hold direct cards and nested zones side by side (custom zones),
+    // and an empty node would previously crash on at(0).
+    QVector<const AbstractDecklistCardNode *> cards;
+    QVector<const InnerDecklistNode *> subZones;
+    for (int i = 0; i < node->size(); i++) {
+        if (auto *card = dynamic_cast<const AbstractDecklistCardNode *>(node->at(i))) {
+            cards.append(card);
+        } else if (auto *zone = dynamic_cast<const InnerDecklistNode *>(node->at(i))) {
+            subZones.append(zone);
+        }
+    }
+
+    if (!cards.isEmpty()) {
         QTextBlockFormat blockFormat;
         QTextCharFormat charFormat;
         charFormat.setFontPointSize(11);
@@ -523,9 +548,9 @@ void DeckLoader::printDeckListNode(QTextCursor *cursor, const InnerDecklistNode
         tableFormat.setCellPadding(0);
         tableFormat.setCellSpacing(0);
         tableFormat.setBorder(0);
-        QTextTable *table = cursor->insertTable(node->size() + 1, totalColumns, tableFormat);
-        for (int i = 0; i < node->size(); i++) {
-            auto *card = dynamic_cast<AbstractDecklistCardNode *>(node->at(i));
+        QTextTable *table = cursor->insertTable(cards.size() + 1, totalColumns, tableFormat);
+        for (int i = 0; i < cards.size(); i++) {
+            const AbstractDecklistCardNode *card = cards[i];
 
             QTextCharFormat cellCharFormat;
             cellCharFormat.setFontPointSize(9);
@@ -540,7 +565,13 @@ void DeckLoader::printDeckListNode(QTextCursor *cursor, const InnerDecklistNode
             cellCursor = cell.firstCursorPosition();
             cellCursor.insertText(card->getName());
         }
-    } else if (node->height() == 2) {
+    }
+
+    for (const InnerDecklistNode *subZone : subZones) {
+        if (subZone->isEmpty()) {
+            continue;
+        }
+
         QTextBlockFormat blockFormat;
         QTextCharFormat charFormat;
         charFormat.setFontPointSize(14);
@@ -559,10 +590,8 @@ void DeckLoader::printDeckListNode(QTextCursor *cursor, const InnerDecklistNode
         tableFormat.setColumnWidthConstraints(constraints);
 
         QTextTable *table = cursor->insertTable(1, totalColumns, tableFormat);
-        for (int i = 0; i < node->size(); i++) {
-            QTextCursor cellCursor = table->cellAt(0, (i * totalColumns) / node->size()).lastCursorPosition();
-            printDeckListNode(&cellCursor, dynamic_cast<InnerDecklistNode *>(node->at(i)));
-        }
+        QTextCursor cellCursor = table->cellAt(0, 0).firstCursorPosition();
+        printDeckListNode(&cellCursor, subZone);
     }
 
     cursor->movePosition(QTextCursor::End);

cockatrice/src/interface/widgets/deck_editor/card_database_view.cpp

@@ -90,6 +90,13 @@ void CardDatabaseView::decrementCard(const QString &zoneName)
     emit cardDecremented(currentCardName(), zoneName);
 }
 
+void CardDatabaseView::setZoneMenuProvider(const std::function<QList<QPair<QString, QStringList>>()> &provider,
+                                           const std::function<QString()> &newZoneHandler)
+{
+    zoneMenuProvider = provider;
+    this->newZoneHandler = newZoneHandler;
+}
+
 void CardDatabaseView::updateCard(const QModelIndex &current, const QModelIndex & /*previous*/)
 {
     if (!current.isValid()) {
@@ -142,6 +149,50 @@ void CardDatabaseView::openCustomMenu(QPoint point)
             [this, card] { emit cardAdded(card->getName(), DECK_ZONE_SIDE); });
     connect(selectPrinting, &QAction::triggered, this, &CardDatabaseView::selectPrintingClicked);
 
+    if (zoneMenuProvider) {
+        QMenu *addToZoneMenu = menu.addMenu(tr("Add to Zone"));
+        const auto zoneBoards = zoneMenuProvider();
+        for (const QString &boardName : InnerDecklistNode::boardZoneNames()) {
+            // Boards with zones nest their children so no two menu entries
+            // share a visible name: "Maindeck ▸ { Maindeck (whole board), … }".
+            const QStringList customZones = [&zoneBoards, boardName] {
+                for (const auto &zoneBoard : zoneBoards) {
+                    if (zoneBoard.first == boardName) {
+                        return zoneBoard.second;
+                    }
+                }
+                return QStringList();
+            }();
+            if (customZones.isEmpty()) {
+                QAction *action = addToZoneMenu->addAction(InnerDecklistNode::visibleNameFromName(boardName));
+                connect(action, &QAction::triggered, this,
+                        [this, card, boardName] { emit cardAdded(card->getName(), boardName); });
+            } else {
+                QMenu *boardSubmenu = addToZoneMenu->addMenu(InnerDecklistNode::visibleNameFromName(boardName));
+                QAction *wholeBoardAction = boardSubmenu->addAction(InnerDecklistNode::visibleNameFromName(boardName));
+                connect(wholeBoardAction, &QAction::triggered, this,
+                        [this, card, boardName] { emit cardAdded(card->getName(), boardName); });
+                for (const QString &zoneName : customZones) {
+                    QAction *action = boardSubmenu->addAction(zoneName);
+                    connect(action, &QAction::triggered, this,
+                            [this, card, zoneName] { emit cardAdded(card->getName(), zoneName); });
+                }
+            }
+        }
+
+        if (newZoneHandler) {
+            addToZoneMenu->addSeparator();
+
+            QAction *newZoneAction = addToZoneMenu->addAction(tr("Create &new zone..."));
+            connect(newZoneAction, &QAction::triggered, this, [this, card] {
+                const QString zoneName = newZoneHandler();
+                if (!zoneName.isEmpty()) {
+                    emit cardAdded(card->getName(), zoneName);
+                }
+            });
+        }
+    }
+
     if (canBeCommander(*card)) {
         QAction *edhRecCommander = menu.addAction(tr("Show on EDHRec (Commander)"));
         connect(edhRecCommander, &QAction::triggered, this, [this, card] { emit edhrecClicked(card, true); });

cockatrice/src/interface/widgets/deck_editor/card_database_view.h

@@ -4,6 +4,7 @@
 #include "../../key_signals.h"
 
 #include <QTreeView>
+#include <functional>
 #include <libcockatrice/card/card_info.h>
 
 class CardDatabaseModel;
@@ -19,6 +20,13 @@ class CardDatabaseView : public QTreeView
     KeySignals searchKeySignals;
     CardDatabaseDisplayModel *databaseDisplayModel;
 
+    /// Provides the custom zones available in the current deck, grouped by board zone.
+    /// The list contains (board zone name, custom zone names) pairs for every board.
+    std::function<QList<QPair<QString, QStringList>>()> zoneMenuProvider;
+    /// Handler invoked when the user picks "New zone..." from the add-to-zone menu.
+    /// Returns the name of the created zone, or an empty string if creation was cancelled.
+    std::function<QString()> newZoneHandler;
+
 public:
     explicit CardDatabaseView(QWidget *parent, CardDatabaseDisplayModel *model);
 
@@ -33,6 +41,17 @@ public:
         return &searchKeySignals;
     }
 
+    /**
+     * @brief Sets the provider used to populate the "Add to zone" submenu of the context menu.
+     * If no provider is set, the submenu is not shown.
+     *
+     * @param provider Returns the custom zones of the current deck, grouped by board zone
+     * @param newZoneHandler Creates a new custom zone and returns its name, or an empty string
+     *                       if creation was cancelled. The menu entry is hidden when not provided.
+     */
+    void setZoneMenuProvider(const std::function<QList<QPair<QString, QStringList>>()> &provider,
+                             const std::function<QString()> &newZoneHandler);
+
 signals:
     void cardChanged(const QString &cardName);
 

cockatrice/src/interface/widgets/deck_editor/deck_editor_card_database_dock_widget.cpp

@@ -1,5 +1,12 @@
 #include "deck_editor_card_database_dock_widget.h"
 
+#include "../../../interface/widgets/tabs/abstract_tab_deck_editor.h"
+#include "card_database_view.h"
+#include "deck_state_manager.h"
+#include "deck_zone_dialog.h"
+
+#include <libcockatrice/deck_list/deck_list_node_tree.h>
+
 DeckEditorCardDatabaseDockWidget::DeckEditorCardDatabaseDockWidget(AbstractTabDeckEditor *parent) : QDockWidget(parent)
 {
     setObjectName("databaseDisplayDock");
@@ -15,6 +22,27 @@ void DeckEditorCardDatabaseDockWidget::createDatabaseDisplayDock(AbstractTabDeck
 {
     databaseDisplayWidget = new DeckEditorDatabaseDisplayWidget(this, deckEditor->databaseModel);
 
+    databaseDisplayWidget->getDatabaseView()->setZoneMenuProvider(
+        [deckEditor]() -> QList<QPair<QString, QStringList>> {
+            QList<QPair<QString, QStringList>> result;
+            auto *deckListModel = deckEditor->deckStateManager->getModel();
+            for (const QString &boardName : InnerDecklistNode::boardZoneNames()) {
+                result.append({boardName, deckListModel->getCustomZoneNames(boardName)});
+            }
+            return result;
+        },
+        [this, deckEditor]() -> QString {
+            QString boardName;
+            const QString zoneName =
+                DeckZoneDialog::promptForNewZone(this, {}, &boardName, [deckEditor](const QString &candidate) {
+                    return deckEditor->deckStateManager->validateNewZoneName(candidate);
+                });
+            if (!zoneName.isEmpty()) {
+                deckEditor->deckStateManager->createCustomZone(boardName, zoneName);
+            }
+            return zoneName;
+        });
+
     auto *frame = new QVBoxLayout;
     frame->setObjectName("databaseDisplayFrame");
     frame->addWidget(databaseDisplayWidget);

cockatrice/src/interface/widgets/deck_editor/deck_editor_deck_dock_widget.cpp

@@ -7,15 +7,18 @@
 #include "../tabs/api/commander_spellbook/commander_bracket_widget.h"
 #include "deck_list_style_proxy.h"
 #include "deck_state_manager.h"
+#include "deck_zone_dialog.h"
 
 #include <QComboBox>
 #include <QDockWidget>
 #include <QHeaderView>
 #include <QLabel>
+#include <QMessageBox>
 #include <QPushButton>
 #include <QSplitter>
 #include <QTextEdit>
 #include <libcockatrice/card/database/card_database_manager.h>
+#include <libcockatrice/deck_list/deck_list_node_tree.h>
 #include <libcockatrice/settings/deck_editor_settings.h>
 #include <libcockatrice/settings/interface_settings.h>
 #include <libcockatrice/utility/macros.h>
@@ -772,14 +775,183 @@ void DeckEditorDeckDockWidget::offsetCountAtIndex(const QModelIndex &idx, bool i
 
 void DeckEditorDeckDockWidget::decklistCustomMenu(QPoint point)
 {
+    const QModelIndex sourceIndex = proxy->mapToSource(deckView->indexAt(point));
+
     QMenu menu;
 
+    const bool isCustomZoneRow = sourceIndex.isValid() && sourceIndex.data(DeckRoles::IsCustomZoneRole).toBool();
+    const bool isBoardZoneRow = sourceIndex.isValid() && !isCustomZoneRow && !sourceIndex.parent().isValid();
+    const bool isCardRow =
+        sourceIndex.isValid() && !isCustomZoneRow && !isBoardZoneRow && !getModel()->hasChildren(sourceIndex);
+
+    // Walk the row up to its top-level node to find the hosting board. Cards in
+    // the tokens board cannot be moved (moveCardToZone bails for it), so the
+    // move menu is skipped for them.
+    QString currentBoardName;
+    QModelIndex board = sourceIndex.parent();
+    while (board.isValid() && board.parent().isValid()) {
+        board = board.parent();
+    }
+    if (board.isValid()) {
+        currentBoardName = board.siblingAtColumn(DeckListModelColumns::CARD_NAME).data(Qt::EditRole).toString();
+    }
+
+    if (isCardRow) {
+        if (currentBoardName != DECK_ZONE_TOKENS) {
+            addMoveToZoneMenu(&menu, sourceIndex, currentBoardName);
+            menu.addSeparator();
+        }
+    } else if (isCustomZoneRow) {
+        const QString zoneName =
+            sourceIndex.siblingAtColumn(DeckListModelColumns::CARD_NAME).data(Qt::EditRole).toString();
+
+        QAction *renameAction = menu.addAction(tr("&Rename zone..."));
+        connect(renameAction, &QAction::triggered, this, [this, zoneName] {
+            // The unchanged name must not validate as a duplicate.
+            const QString newName =
+                DeckZoneDialog::promptForRename(this, zoneName, [this, zoneName](const QString &candidate) {
+                    return candidate == zoneName ? QString() : deckStateManager->validateNewZoneName(candidate);
+                });
+            if (!newName.isEmpty() && newName != zoneName) {
+                deckStateManager->renameCustomZone(zoneName, newName);
+            }
+        });
+
+        QMenu *boardMenu = menu.addMenu(tr("Change &board"));
+        addChangeBoardMenu(boardMenu, zoneName);
+
+        QAction *deleteAction = menu.addAction(tr("&Delete zone"));
+        const bool zoneHasCards = getModel()->hasChildren(sourceIndex);
+        deleteAction->setEnabled(!zoneHasCards);
+        if (zoneHasCards) {
+            deleteAction->setToolTip(tr("Move or remove all cards first."));
+            menu.setToolTipsVisible(true);
+        }
+        connect(deleteAction, &QAction::triggered, this, [this, zoneName] {
+            const auto result =
+                QMessageBox::warning(this, tr("Delete zone"), tr("Delete the zone \"%1\"?").arg(zoneName),
+                                     QMessageBox::Yes | QMessageBox::No, QMessageBox::No);
+            if (result == QMessageBox::Yes) {
+                deckStateManager->removeCustomZone(zoneName);
+            }
+        });
+        menu.addSeparator();
+    } else if (isBoardZoneRow) {
+        const QString boardName =
+            sourceIndex.siblingAtColumn(DeckListModelColumns::CARD_NAME).data(Qt::EditRole).toString();
+        // Tokens cannot host custom zones, so only offer the action on real boards.
+        const bool canHostCustomZones =
+            boardName == DECK_ZONE_MAIN || boardName == DECK_ZONE_SIDE || boardName == DECK_ZONE_MAYBEBOARD;
+        if (canHostCustomZones) {
+            addNewZoneAction(&menu, boardName);
+            menu.addSeparator();
+        }
+    } else if (!sourceIndex.isValid()) {
+        addNewZoneAction(&menu);
+        menu.addSeparator();
+    }
+
     QAction *selectPrinting = menu.addAction(tr("Select Printing"));
     connect(selectPrinting, &QAction::triggered, deckEditor, &AbstractTabDeckEditor::showPrintingSelector);
 
     menu.exec(deckView->mapToGlobal(point));
 }
 
+void DeckEditorDeckDockWidget::addMoveToZoneMenu(QMenu *menu,
+                                                 const QModelIndex &sourceCardIndex,
+                                                 const QString &currentBoardName)
+{
+    const auto addMoveAction = [this, sourceCardIndex](QMenu *targetMenu, const QString &targetZoneName,
+                                                       const QString &label, bool enabled) {
+        QAction *action = targetMenu->addAction(label);
+        action->setEnabled(enabled);
+        if (enabled) {
+            connect(action, &QAction::triggered, this, [this, sourceCardIndex, targetZoneName] {
+                deckStateManager->moveCardToZone(sourceCardIndex, targetZoneName);
+            });
+        }
+    };
+
+    const auto tree = deckStateManager->getDeckListShared()->getTree();
+
+    QMenu *moveMenu = menu->addMenu(tr("Move to &zone"));
+
+    for (const QString &boardName : InnerDecklistNode::boardZoneNames()) {
+        const QString boardLabel = InnerDecklistNode::visibleNameFromName(boardName);
+        const auto customZones = tree->getCustomZones(boardName);
+
+        // Boards with zones nest their children so no two menu entries share a
+        // visible name: "Maindeck ▸ { Maindeck (whole board), Removal, … }".
+        // The board the card already lives on is marked instead of offered.
+        if (!customZones.isEmpty()) {
+            QMenu *boardSubmenu = moveMenu->addMenu(boardLabel);
+            addMoveAction(boardSubmenu, boardName, boardLabel, boardName != currentBoardName);
+            for (const auto *customZone : customZones) {
+                addMoveAction(boardSubmenu, customZone->getName(), customZone->getName(), true);
+            }
+        } else {
+            addMoveAction(moveMenu, boardName, boardLabel, boardName != currentBoardName);
+        }
+    }
+
+    moveMenu->addSeparator();
+
+    QAction *newZoneAction = moveMenu->addAction(tr("Create new zone and move &here..."));
+    connect(newZoneAction, &QAction::triggered, this, [this, sourceCardIndex, currentBoardName] {
+        const QString zoneName = createNewCustomZone(currentBoardName);
+        if (!zoneName.isEmpty()) {
+            deckStateManager->moveCardToZone(sourceCardIndex, zoneName);
+        }
+    });
+}
+
+void DeckEditorDeckDockWidget::addChangeBoardMenu(QMenu *menu, const QString &zoneName)
+{
+    const auto tree = deckStateManager->getDeckListShared()->getTree();
+    for (const QString &boardName : InnerDecklistNode::boardZoneNames()) {
+        QAction *action = menu->addAction(InnerDecklistNode::visibleNameFromName(boardName));
+
+        // The board currently holding the zone is marked instead of offered.
+        // Duplicate names cannot come up through the editor, so this doubles as
+        // the uniqueness guard for imported decks.
+        bool holdsTheZone = false;
+        for (const auto *customZone : tree->getCustomZones(boardName)) {
+            if (customZone->getName() == zoneName) {
+                holdsTheZone = true;
+                break;
+            }
+        }
+        if (holdsTheZone) {
+            action->setCheckable(true);
+            action->setChecked(true);
+            continue;
+        }
+
+        connect(action, &QAction::triggered, this,
+                [this, zoneName, boardName] { deckStateManager->moveCustomZone(zoneName, boardName); });
+    }
+}
+
+void DeckEditorDeckDockWidget::addNewZoneAction(QMenu *menu, const QString &initialBoardName)
+{
+    QAction *newZoneAction = menu->addAction(tr("Create &new zone..."));
+    connect(newZoneAction, &QAction::triggered, this,
+            [this, initialBoardName] { createNewCustomZone(initialBoardName); });
+}
+
+QString DeckEditorDeckDockWidget::createNewCustomZone(const QString &initialBoardName)
+{
+    QString boardName;
+    const QString zoneName =
+        DeckZoneDialog::promptForNewZone(this, initialBoardName, &boardName, [this](const QString &candidate) {
+            return deckStateManager->validateNewZoneName(candidate);
+        });
+    if (!zoneName.isEmpty()) {
+        deckStateManager->createCustomZone(boardName, zoneName);
+    }
+    return zoneName;
+}
+
 void DeckEditorDeckDockWidget::refreshShortcuts()
 {
     ShortcutsSettings &shortcuts = SettingsCache::instance().shortcuts();

cockatrice/src/interface/widgets/deck_editor/deck_editor_deck_dock_widget.h

@@ -19,6 +19,7 @@
 #include <QComboBox>
 #include <QDockWidget>
 #include <QLabel>
+#include <QMenu>
 #include <QPushButton>
 #include <QTextEdit>
 #include <QTreeView>
@@ -102,6 +103,11 @@ private:
     [[nodiscard]] QModelIndexList getSelectedCardNodeSourceIndices() const;
     void offsetCountAtIndex(const QModelIndex &idx, bool isIncrement);
 
+    void addMoveToZoneMenu(QMenu *menu, const QModelIndex &sourceCardIndex, const QString &currentBoardName);
+    void addChangeBoardMenu(QMenu *menu, const QString &zoneName);
+    QString createNewCustomZone(const QString &initialBoardName = {});
+    void addNewZoneAction(QMenu *menu, const QString &initialBoardName = {});
+
 private slots:
     void decklistCustomMenu(QPoint point);
     void updateCard(QModelIndex, const QModelIndex &current);

cockatrice/src/interface/widgets/deck_editor/deck_state_manager.cpp

@@ -2,6 +2,7 @@
 
 #include <libcockatrice/card/database/card_database_manager.h>
 #include <libcockatrice/deck_list/deck_list_history_manager.h>
+#include <libcockatrice/deck_list/tree/inner_deck_list_node.h>
 
 DeckStateManager::DeckStateManager(QObject *parent)
     : QObject(parent), deckList(QSharedPointer<DeckList>(new DeckList)),
@@ -307,6 +308,180 @@ bool DeckStateManager::decrementCountAtIndex(const QModelIndex &idx)
     return offsetCountAtIndex(idx, -1);
 }
 
+bool DeckStateManager::moveCardToZone(const QModelIndex &idx, const QString &targetZoneName)
+{
+    if (!idx.isValid()) {
+        return false;
+    }
+
+    // Only actual card rows can be moved. Group or zone rows report an
+    // aggregate amount and must never be deleted by this operation.
+    if (!idx.data(DeckRoles::IsCardRole).toBool()) {
+        return false;
+    }
+
+    QString cardName = idx.siblingAtColumn(DeckListModelColumns::CARD_NAME).data(Qt::EditRole).toString();
+    QString providerId = idx.siblingAtColumn(DeckListModelColumns::CARD_PROVIDER_ID).data(Qt::DisplayRole).toString();
+    int copies = idx.siblingAtColumn(DeckListModelColumns::CARD_AMOUNT).data(Qt::EditRole).toInt();
+
+    if (copies <= 0) {
+        return false;
+    }
+
+    // Tokens only live in the tokens zone and cannot be moved into decks.
+    CardInfoPtr info = CardDatabaseManager::query()->getCardInfo(cardName);
+    if (info && info->getIsToken()) {
+        return false;
+    }
+
+    // Determine the zone the card currently lives in: the enclosing custom
+    // zone, or the nearest top-level zone (board zone or legacy zone).
+    QString currentZoneName;
+    for (QModelIndex ancestor = idx.parent(); ancestor.isValid(); ancestor = ancestor.parent()) {
+        bool isCustomZone = ancestor.data(DeckRoles::IsCustomZoneRole).toBool();
+        if (isCustomZone || !ancestor.parent().isValid()) {
+            currentZoneName = ancestor.siblingAtColumn(DeckListModelColumns::CARD_NAME).data(Qt::EditRole).toString();
+            break;
+        }
+    }
+
+    if (currentZoneName == targetZoneName) {
+        return false;
+    }
+
+    QString reason = tr("Moved %1 × \"%2\" (%3) to %4")
+                         .arg(copies)
+                         .arg(cardName)
+                         .arg(providerId)
+                         .arg(InnerDecklistNode::visibleNameFromName(targetZoneName));
+
+    return modifyDeck(reason, [&idx, &cardName, &providerId, &targetZoneName, copies](auto model) {
+        if (!model->removeRow(idx.row(), idx.parent())) {
+            return false;
+        }
+
+        if (ExactCard card = CardDatabaseManager::query()->getCard({cardName, providerId})) {
+            for (int i = 0; i < copies; ++i) {
+                model->addCard(card, targetZoneName);
+            }
+        } else {
+            for (int i = 0; i < copies; ++i) {
+                model->addPreferredPrintingCard(cardName, targetZoneName, true);
+            }
+        }
+
+        return true;
+    });
+}
+
+bool DeckStateManager::createCustomZone(const QString &boardZoneName, const QString &zoneName)
+{
+    const QString trimmedZoneName = zoneName.trimmed();
+    if (trimmedZoneName.isEmpty()) {
+        return false;
+    }
+
+    QString reason =
+        tr("Created zone \"%1\" in %2").arg(trimmedZoneName, InnerDecklistNode::visibleNameFromName(boardZoneName));
+
+    return modifyTree(reason, [&boardZoneName, &trimmedZoneName](DecklistNodeTree *tree) {
+        return tree->addCustomZone(boardZoneName, trimmedZoneName) != nullptr;
+    });
+}
+
+bool DeckStateManager::renameCustomZone(const QString &oldZoneName, const QString &newZoneName)
+{
+    const QString trimmedNewZoneName = newZoneName.trimmed();
+    if (trimmedNewZoneName.isEmpty() || oldZoneName == trimmedNewZoneName) {
+        return false;
+    }
+
+    QString reason = tr("Renamed zone \"%1\" to \"%2\"").arg(oldZoneName, trimmedNewZoneName);
+
+    return modifyTree(reason, [&oldZoneName, &trimmedNewZoneName](DecklistNodeTree *tree) {
+        return tree->renameCustomZone(oldZoneName, trimmedNewZoneName);
+    });
+}
+
+bool DeckStateManager::moveCustomZone(const QString &zoneName, const QString &newBoardZoneName)
+{
+    const auto *tree = deckList->getTree();
+
+    // Locate the board currently holding the zone.
+    QString currentBoardName;
+    for (const QString &boardName : InnerDecklistNode::boardZoneNames()) {
+        for (const auto *zone : tree->getCustomZones(boardName)) {
+            if (zone->getName() == zoneName) {
+                currentBoardName = boardName;
+                break;
+            }
+        }
+        if (!currentBoardName.isEmpty()) {
+            break;
+        }
+    }
+
+    if (currentBoardName.isEmpty()) {
+        return false;
+    }
+
+    // Same-board moves are no-ops and must not pollute the history.
+    if (currentBoardName == newBoardZoneName) {
+        return true;
+    }
+
+    // Zone names are deck-unique among zones created through this manager, so a
+    // same-named zone on the target board can only come from an imported deck.
+    // Refuse the move instead of silently stacking same-named zones.
+    for (const auto *zone : tree->getCustomZones(newBoardZoneName)) {
+        if (zone->getName() == zoneName) {
+            return false;
+        }
+    }
+
+    QString reason =
+        tr("Moved zone \"%1\" to %2").arg(zoneName, InnerDecklistNode::visibleNameFromName(newBoardZoneName));
+
+    return modifyTree(reason, [&zoneName, &newBoardZoneName](DecklistNodeTree *tree) {
+        return tree->moveCustomZone(zoneName, newBoardZoneName);
+    });
+}
+
+bool DeckStateManager::removeCustomZone(const QString &zoneName)
+{
+    QString reason = tr("Deleted zone \"%1\"").arg(zoneName);
+
+    return modifyTree(reason, [&zoneName](DecklistNodeTree *tree) { return tree->removeCustomZone(zoneName); });
+}
+
+QString DeckStateManager::validateNewZoneName(const QString &zoneName) const
+{
+    if (zoneName.trimmed().isEmpty()) {
+        return tr("Enter a zone name.");
+    }
+
+    const QString trimmedZoneName = zoneName.trimmed();
+
+    // The standard zone names are reserved even before they exist.
+    if (trimmedZoneName == DECK_ZONE_MAIN || trimmedZoneName == DECK_ZONE_SIDE ||
+        trimmedZoneName == DECK_ZONE_MAYBEBOARD || trimmedZoneName == DECK_ZONE_TOKENS) {
+        return tr("This name is reserved.");
+    }
+
+    const auto *tree = deckList->getTree();
+
+    // Reuse the tree's own uniqueness contract: any top-level zone and any
+    // custom zone on *every* board claims the name (hasZoneName also reserves
+    // the standard board names, which we already rejected with a dedicated
+    // message above). Scanning only the standard boards here would miss a
+    // custom zone an imported deck carries under `tokens`.
+    if (tree->hasZoneName(trimmedZoneName)) {
+        return tr("A zone with this name already exists.");
+    }
+
+    return {};
+}
+
 bool DeckStateManager::offsetCountAtIndex(const QModelIndex &idx, int offset)
 {
     if (!idx.isValid()) {
@@ -367,6 +542,22 @@ void DeckStateManager::requestHistorySave(const QString &reason)
     historyManager->save(deckList->createMemento(reason));
 }
 
+bool DeckStateManager::modifyTree(const QString &reason, const std::function<bool(DecklistNodeTree *)> &operation)
+{
+    DeckListMemento memento = deckList->createMemento(reason);
+    bool success = operation(deckList->getTree());
+
+    if (success) {
+        historyManager->save(memento);
+        deckListModel->rebuildTree();
+        deckList->refreshDeckHash();
+        emit deckListModel->deckHashChanged();
+        doCardModified();
+    }
+
+    return success;
+}
+
 /**
  * @brief Handles updating state and emitting signals whenever the cards are modified
  */

cockatrice/src/interface/widgets/deck_editor/deck_state_manager.h

@@ -5,6 +5,7 @@
 #include "deck_list_model.h"
 
 #include <QSharedPointer>
+#include <functional>
 #include <libcockatrice/deck_list/deck_list.h>
 
 class DeckListHistoryManager;
@@ -236,6 +237,68 @@ public:
      */
     bool decrementCountAtIndex(const QModelIndex &idx);
 
+    /**
+     * @brief Moves all copies of the card at the given index to the given zone.
+     * No-ops if the index is invalid, not a card node, the card is a token, or the
+     * card is already in the target zone.
+     * Saves the operation to history if successful.
+     *
+     * @param idx The model index of the card to move
+     * @param targetZoneName The zone to move the card to (board zone or custom zone name)
+     * @return Whether the operation was successfully performed
+     */
+    bool moveCardToZone(const QModelIndex &idx, const QString &targetZoneName);
+
+    /**
+     * @brief Creates a new custom zone nested under a board zone.
+     * Saves the operation to history if successful.
+     *
+     * @param boardZoneName The board zone to nest the custom zone under
+     * @param zoneName The name of the new custom zone. Gets trimmed and must be
+     *        unique across the deck.
+     * @return Whether the zone was created
+     */
+    bool createCustomZone(const QString &boardZoneName, const QString &zoneName);
+
+    /**
+     * @brief Renames a custom zone.
+     * Saves the operation to history if successful.
+     *
+     * @param oldZoneName The current name of the custom zone
+     * @param newZoneName The new name. Gets trimmed and must be unique across the deck.
+     * @return Whether the rename succeeded
+     */
+    bool renameCustomZone(const QString &oldZoneName, const QString &newZoneName);
+
+    /**
+     * @brief Moves a custom zone (and its cards) to a different board zone.
+     * Same-board moves succeed without creating a history entry.
+     * Saves the operation to history if successful.
+     *
+     * @param zoneName The custom zone to move
+     * @param newBoardZoneName The board zone to move the custom zone under
+     * @return Whether the move succeeded
+     */
+    bool moveCustomZone(const QString &zoneName, const QString &newBoardZoneName);
+
+    /**
+     * @brief Removes a custom zone and all its cards.
+     * Saves the operation to history if successful.
+     *
+     * @param zoneName The custom zone to remove
+     * @return Whether the zone was removed
+     */
+    bool removeCustomZone(const QString &zoneName);
+
+    /**
+     * @brief Checks whether a candidate name is usable for a new custom zone.
+     *
+     * @param zoneName The candidate name
+     * @return An empty string when the name is usable, otherwise a user-facing
+     *         error message describing the problem
+     */
+    [[nodiscard]] QString validateNewZoneName(const QString &zoneName) const;
+
     /**
      * Undoes n steps of the history, setting the decklist state and updating the current step in the historyManager.
      * @param steps Number of steps to undo.
@@ -257,6 +320,7 @@ public slots:
 
 private:
     bool offsetCountAtIndex(const QModelIndex &idx, int offset);
+    bool modifyTree(const QString &reason, const std::function<bool(DecklistNodeTree *)> &operation);
     void doCardModified();
     void doMetadataModified();
 

cockatrice/src/interface/widgets/deck_editor/deck_zone_dialog.cpp

@@ -0,0 +1,145 @@
+#include "deck_zone_dialog.h"
+
+#include <QComboBox>
+#include <QDialogButtonBox>
+#include <QLabel>
+#include <QLineEdit>
+#include <QPushButton>
+#include <QVBoxLayout>
+#include <libcockatrice/deck_list/tree/inner_deck_list_node.h>
+#include <libcockatrice/utility/string_limits.h>
+
+DeckZoneDialog::DeckZoneDialog(QWidget *parent,
+                               const QString &initialBoardName,
+                               const std::function<QString(const QString &)> &_nameValidator,
+                               bool _allowBoardSelection)
+    : QDialog(parent), nameValidator(_nameValidator), allowBoardSelection(_allowBoardSelection)
+{
+    nameLabel = new QLabel(this);
+    nameEdit = new QLineEdit(this);
+    nameEdit->setMaxLength(MAX_NAME_LENGTH);
+
+    errorLabel = new QLabel(this);
+    errorLabel->hide();
+
+    boardLabel = new QLabel(this);
+    boardCombo = new QComboBox(this);
+    for (const QString &boardName : InnerDecklistNode::boardZoneNames()) {
+        // Use the icon overload explicitly so `boardName` lands in the user data role
+        // (visible text is applied below in retranslateUi). The two-argument form
+        // addItem({}, boardName) would be ambiguous and resolve to the icon overload
+        // with empty user data, yielding empty entries and an empty getBoardName().
+        boardCombo->addItem({}, {}, boardName);
+    }
+    if (!initialBoardName.isEmpty()) {
+        int idx = boardCombo->findData(initialBoardName);
+        if (idx != -1) {
+            boardCombo->setCurrentIndex(idx);
+        }
+    }
+
+    buttonBox = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel, this);
+    buttonBox->button(QDialogButtonBox::Ok)->setEnabled(false);
+    connect(buttonBox, &QDialogButtonBox::accepted, this, &QDialog::accept);
+    connect(buttonBox, &QDialogButtonBox::rejected, this, &QDialog::reject);
+
+    auto *layout = new QVBoxLayout(this);
+    layout->addWidget(nameLabel);
+    layout->addWidget(nameEdit);
+    layout->addWidget(errorLabel);
+    if (allowBoardSelection) {
+        layout->addWidget(boardLabel);
+        layout->addWidget(boardCombo);
+    } else {
+        boardLabel->hide();
+        boardCombo->hide();
+    }
+    layout->addWidget(buttonBox);
+
+    retranslateUi();
+
+    connect(nameEdit, &QLineEdit::textChanged, this, [this] { validateName(); });
+    validateName();
+
+    nameEdit->setFocus();
+}
+
+QString DeckZoneDialog::getZoneName() const
+{
+    return nameEdit->text().trimmed();
+}
+
+QString DeckZoneDialog::getBoardName() const
+{
+    return boardCombo->currentData().toString();
+}
+
+void DeckZoneDialog::setZoneName(const QString &zoneName)
+{
+    nameEdit->setText(zoneName);
+    nameEdit->selectAll();
+}
+
+void DeckZoneDialog::changeEvent(QEvent *event)
+{
+    QDialog::changeEvent(event);
+
+    if (event->type() == QEvent::LanguageChange) {
+        retranslateUi();
+    }
+}
+
+void DeckZoneDialog::retranslateUi()
+{
+    setWindowTitle(allowBoardSelection ? tr("New zone") : tr("Rename zone"));
+
+    nameLabel->setText(tr("Zone &name:"));
+    nameLabel->setBuddy(nameEdit);
+
+    boardLabel->setText(tr("&Parent zone:"));
+    boardLabel->setBuddy(boardCombo);
+
+    for (int i = 0; i < boardCombo->count(); i++) {
+        boardCombo->setItemText(i, InnerDecklistNode::visibleNameFromName(boardCombo->itemData(i).toString()));
+    }
+}
+
+void DeckZoneDialog::validateName()
+{
+    const QString zoneName = nameEdit->text().trimmed();
+    QString error;
+    if (zoneName.isEmpty()) {
+        error = tr("Enter a zone name.");
+    } else if (nameValidator) {
+        error = nameValidator(zoneName);
+    }
+
+    errorLabel->setText(error);
+    errorLabel->setVisible(!error.isEmpty());
+    buttonBox->button(QDialogButtonBox::Ok)->setEnabled(error.isEmpty());
+}
+
+QString DeckZoneDialog::promptForNewZone(QWidget *parent,
+                                         const QString &initialBoardName,
+                                         QString *chosenBoardName,
+                                         const std::function<QString(const QString &)> &nameValidator)
+{
+    DeckZoneDialog dialog(parent, initialBoardName, nameValidator);
+    if (dialog.exec() != QDialog::Accepted) {
+        return {};
+    }
+
+    if (chosenBoardName) {
+        *chosenBoardName = dialog.getBoardName();
+    }
+    return dialog.getZoneName();
+}
+
+QString DeckZoneDialog::promptForRename(QWidget *parent,
+                                        const QString &currentZoneName,
+                                        const std::function<QString(const QString &)> &nameValidator)
+{
+    DeckZoneDialog dialog(parent, {}, nameValidator, false);
+    dialog.setZoneName(currentZoneName);
+    return dialog.exec() == QDialog::Accepted ? dialog.getZoneName() : QString();
+}

cockatrice/src/interface/widgets/deck_editor/deck_zone_dialog.h

@@ -0,0 +1,123 @@
+/**
+ * @file deck_zone_dialog.h
+ * @ingroup DeckEditorWidgets
+ * @brief Shared dialog for creating custom deck zones.
+ */
+
+#ifndef DECK_ZONE_DIALOG_H
+#define DECK_ZONE_DIALOG_H
+
+#include <QDialog>
+#include <QEvent>
+#include <QString>
+#include <functional>
+
+class QComboBox;
+class QDialogButtonBox;
+class QLabel;
+class QLineEdit;
+class QWidget;
+
+/**
+ * @brief Modal dialog asking for the name and parent zone of a new custom deck zone.
+ *
+ * Menus construct the dialog transiently around exec(), so validation state only
+ * ever reflects the name currently typed.
+ */
+class DeckZoneDialog : public QDialog
+{
+    Q_OBJECT
+
+public:
+    /**
+     * @brief Constructs the dialog and runs the initial validation pass.
+     *
+     * @param parent The parent widget for the dialog
+     * @param initialBoardName The board zone to preselect in the combo. Unknown names
+     *        fall back to main.
+     * @param _nameValidator Given the trimmed candidate name, returns an empty string
+     *        when it is usable, otherwise a user-facing error message. May be empty.
+     * @param _allowBoardSelection When false the parent-zone combo is hidden and the
+     *        dialog acts as a rename prompt for an existing zone.
+     */
+    explicit DeckZoneDialog(QWidget *parent = nullptr,
+                            const QString &initialBoardName = {},
+                            const std::function<QString(const QString &)> &_nameValidator = {},
+                            bool _allowBoardSelection = true);
+
+    /**
+     * @brief The trimmed zone name entered by the user.
+     */
+    [[nodiscard]] QString getZoneName() const;
+
+    /**
+     * @brief The internal name of the board zone selected in the combo.
+     */
+    [[nodiscard]] QString getBoardName() const;
+
+    /**
+     * @brief Prefills the name field, e.g. with the current name when renaming.
+     *
+     * @param zoneName The text to put into the name field, selected for quick editing
+     */
+    void setZoneName(const QString &zoneName);
+
+    /**
+     * @brief Prompts the user for a new custom zone name and the board zone to nest it under.
+     *
+     * Convenience wrapper that runs DeckZoneDialog modally.
+     *
+     * @param parent The parent widget for the dialog
+     * @param initialBoardName The board zone to preselect in the dialog. Unknown names fall
+     *        back to main.
+     * @param chosenBoardName (out) The internal name of the board zone the user chose
+     * @param nameValidator Optional validator forwarded to the dialog
+     * @return The trimmed zone name, or an empty string if the user cancelled
+     */
+    static QString promptForNewZone(QWidget *parent,
+                                    const QString &initialBoardName,
+                                    QString *chosenBoardName,
+                                    const std::function<QString(const QString &)> &nameValidator = {});
+
+    /**
+     * @brief Prompts the user for a new name for an existing custom zone.
+     *
+     * Same inline validation as promptForNewZone, but without a parent-zone picker.
+     *
+     * @param parent The parent widget for the dialog
+     * @param currentZoneName The current name, prefilled for editing
+     * @param nameValidator Validator deciding whether a candidate name is usable. It sees
+     *        the current name too, so callers wanting to allow unchanged names must
+     *        special-case that themselves.
+     * @return The trimmed new name, or an empty string if the user cancelled
+     */
+    static QString promptForRename(QWidget *parent,
+                                   const QString &currentZoneName,
+                                   const std::function<QString(const QString &)> &nameValidator = {});
+
+protected:
+    void changeEvent(QEvent *event) override;
+
+private:
+    /**
+     * @brief Sets every user-visible string. Runs on construction and on runtime
+     * language changes.
+     */
+    void retranslateUi();
+
+    /**
+     * @brief Validates the current input, toggling Ok and the inline error label.
+     */
+    void validateName();
+
+    QLabel *nameLabel;
+    QLineEdit *nameEdit;
+    QLabel *errorLabel;
+    QLabel *boardLabel;
+    QComboBox *boardCombo;
+    QDialogButtonBox *buttonBox;
+    std::function<QString(const QString &)> nameValidator;
+    bool allowBoardSelection;
+};
+
+#endif // DECK_ZONE_DIALOG_H

cockatrice/src/interface/widgets/tabs/visual_deck_editor/tab_deck_editor_visual.cpp

@@ -4,6 +4,7 @@
 #include "../../../../client/settings/shortcuts_settings.h"
 #include "../../cards/card_info_display_widget.h"
 #include "../../deck_editor/deck_state_manager.h"
+#include "../../deck_editor/deck_zone_dialog.h"
 #include "../../filters/filter_builder.h"
 #include "../../interface/pixel_map_generator.h"
 #include "../../interface/widgets/cards/card_info_frame_widget.h"
@@ -84,6 +85,7 @@ void TabDeckEditorVisual::createCentralFrame()
     connect(tabContainer, &TabDeckEditorVisualTabWidget::printingSelectorRequested, this,
             &TabDeckEditorVisual::showPrintingSelector);
     connect(tabContainer, &TabDeckEditorVisualTabWidget::cardInfoRequested, this, &TabDeckEditorVisual::updateCardInfo);
+    tabContainer->visualDatabaseDisplay->setNewZoneCreator([this] { return createNewZone(); });
 
     centralFrame->addWidget(tabContainer);
     setCentralWidget(centralWidget);
@@ -269,6 +271,19 @@ bool TabDeckEditorVisual::actSaveDeckAs()
     return result;
 }
 
+/** @brief Prompts for and creates a new custom deck zone. Returns the name of the created zone. */
+QString TabDeckEditorVisual::createNewZone()
+{
+    QString boardName;
+    const QString zoneName = DeckZoneDialog::promptForNewZone(this, {}, &boardName, [this](const QString &candidate) {
+        return deckStateManager->validateNewZoneName(candidate);
+    });
+    if (!zoneName.isEmpty()) {
+        deckStateManager->createCustomZone(boardName, zoneName);
+    }
+    return zoneName;
+}
+
 /** @brief Refreshes keyboard shortcuts for this tab from settings. */
 void TabDeckEditorVisual::refreshShortcuts()
 {

cockatrice/src/interface/widgets/tabs/visual_deck_editor/tab_deck_editor_visual.h

@@ -165,6 +165,12 @@ public slots:
      */
     bool actSaveDeckAs() override;
 
+    /**
+     * @brief Prompts for and creates a new custom deck zone.
+     * @return The name of the created zone, or an empty string if creation was cancelled.
+     */
+    QString createNewZone();
+
 private:
     /**
      * @brief Sets the deck for this tab and selects the sub-tab to open on

cockatrice/src/interface/widgets/visual_database_display/visual_database_display_widget.cpp

@@ -21,6 +21,7 @@
 #include <libcockatrice/card/card_info_comparator.h>
 #include <libcockatrice/card/database/card_database.h>
 #include <libcockatrice/card/database/card_database_manager.h>
+#include <libcockatrice/deck_list/tree/inner_deck_list_node.h>
 #include <libcockatrice/settings/cards_display_settings.h>
 #include <utility>
 
@@ -89,6 +90,19 @@ VisualDatabaseDisplayWidget::VisualDatabaseDisplayWidget(QWidget *parent,
     databaseView->setItemDelegate(nullptr);
     databaseView->setVisible(false);
 
+    // Without a deck model there is nothing to add cards to, so the zone menu stays hidden.
+    if (deckListModel) {
+        databaseView->setZoneMenuProvider(
+            [deckListModel]() -> QList<QPair<QString, QStringList>> {
+                QList<QPair<QString, QStringList>> result;
+                for (const QString &boardName : InnerDecklistNode::boardZoneNames()) {
+                    result.append({boardName, deckListModel->getCustomZoneNames(boardName)});
+                }
+                return result;
+            },
+            [this] { return newZoneCreator ? newZoneCreator() : QString(); });
+    }
+
     searchEdit->setTreeView(databaseView);
     searchEdit->installEventFilter(databaseView->getKeySignals());
 
@@ -195,6 +209,11 @@ void VisualDatabaseDisplayWidget::showEvent(QShowEvent *event)
     initializeFilters();
 }
 
+void VisualDatabaseDisplayWidget::setNewZoneCreator(const std::function<QString()> &creator)
+{
+    newZoneCreator = creator;
+}
+
 void VisualDatabaseDisplayWidget::retranslateUi()
 {
     databaseLoadIndicator->setText(tr("Loading database ..."));

cockatrice/src/interface/widgets/visual_database_display/visual_database_display_widget.h

@@ -22,6 +22,7 @@
 #include <QVBoxLayout>
 #include <QWheelEvent>
 #include <QWidget>
+#include <functional>
 #include <libcockatrice/models/database/card_database_model.h>
 #include <libcockatrice/models/deck_list/deck_list_model.h>
 #include <qscrollarea.h>
@@ -46,6 +47,12 @@ public:
     void sortCardList(const QStringList &properties, Qt::SortOrder order) const;
     void setDeckList(const DeckList &new_deck_list_model);
 
+    /**
+     * @brief Sets the callback used to create a custom zone from the add-to-zone menu.
+     * The callback returns the name of the created zone, or an empty string if creation was cancelled.
+     */
+    void setNewZoneCreator(const std::function<QString()> &creator);
+
     CardDatabaseDisplayModel *getDatabaseDisplayModel()
     {
         return databaseDisplayModel;
@@ -106,6 +113,7 @@ private:
     VisualDatabaseDisplayFilterToolbarWidget *filterContainer;
     CardDatabaseDisplayModel *databaseDisplayModel;
     CardDatabaseView *databaseView;
+    std::function<QString()> newZoneCreator;
     QList<ExactCard> *cards;
     QVBoxLayout *mainLayout;
     QScrollArea *scrollArea;

libcockatrice_deck_list/libcockatrice/deck_list/deck_list_node_tree.h

@@ -115,6 +115,15 @@ public:
      */
     QList<const InnerDecklistNode *> getCustomZones(const QString &boardZoneName) const;
 
+    /**
+     * @brief Checks whether a zone name is taken anywhere in the deck.
+     *
+     * Covers the standard board names and any top-level or nested custom zone.
+     * @param zoneName The checked name.
+     * @return true if the name is reserved or already in use.
+     */
+    bool hasZoneName(const QString &zoneName) const;
+
     /**
      * @brief Applies a function to every card in the deck tree. This can modify the cards.
      *
@@ -129,7 +138,6 @@ private:
     InnerDecklistNode *findBoardZone(const QString &boardZoneName) const;
     InnerDecklistNode *findOrCreateBoardZone(const QString &boardZoneName);
     InnerDecklistNode *findCustomZoneByName(const QString &zoneName) const;
-    bool hasZoneName(const QString &zoneName) const;
 };
 
 #endif // COCKATRICE_DECKLIST_NODE_TREE_H

libcockatrice_deck_list/libcockatrice/deck_list/tree/inner_deck_list_node.cpp

@@ -43,6 +43,13 @@ void InnerDecklistNode::setSortMethod(DeckSortMethod method)
     }
 }
 
+const QList<QString> &InnerDecklistNode::boardZoneNames()
+{
+    static const QList<QString> names = {QString(DECK_ZONE_MAIN), QString(DECK_ZONE_SIDE),
+                                         QString(DECK_ZONE_MAYBEBOARD)};
+    return names;
+}
+
 QString InnerDecklistNode::getVisibleName() const
 {
     return visibleNameFromName(name);
@@ -87,6 +94,9 @@ AbstractDecklistNode *InnerDecklistNode::findCardChildByNameProviderIdAndNumber(
 
 int InnerDecklistNode::height() const
 {
+    if (isEmpty()) {
+        return 1;
+    }
     return at(0)->height() + 1;
 }
 

libcockatrice_deck_list/libcockatrice/deck_list/tree/inner_deck_list_node.h

@@ -18,6 +18,9 @@
 
 #include "abstract_deck_list_node.h"
 
+#include <QList>
+#include <QString>
+
 /** @brief Constant for the "main" deck zone name. */
 #define DECK_ZONE_MAIN "main"
 /** @brief Constant for the "sideboard" zone name. */
@@ -118,6 +121,13 @@ public:
      */
     static QString visibleNameFromName(const QString &_name);
 
+    /**
+     * @brief The standard board zone names, in display order.
+     *
+     * @return main, side and maybeboard.
+     */
+    static const QList<QString> &boardZoneNames();
+
     /**
      * @brief Get this node’s display-friendly name.
      * @return Human-readable name (zone/group name).

libcockatrice_models/libcockatrice/models/deck_list/deck_list_model.cpp

@@ -378,7 +378,8 @@ bool DeckListModel::removeRows(int row, int count, const QModelIndex &parent)
 
 InnerDecklistNode *DeckListModel::createNodeIfNeeded(const QString &name, InnerDecklistNode *parent)
 {
-    auto *newNode = dynamic_cast<InnerDecklistNode *>(parent->findChild(name));
+    // Group lookups must not resolve a mirrored custom zone that shares the name.
+    auto *newNode = DeckListModelCustomZones::findGroupChild(parent, name);
     if (!newNode) {
         beginInsertRows(nodeToIndex(parent), parent->size(), parent->size());
         newNode = new InnerDecklistNode(name, parent);
@@ -401,7 +402,7 @@ DecklistModelCardNode *DeckListModel::findCardNode(const QString &cardName,
     //    nested under the board.
     if (auto *zoneNode = dynamic_cast<InnerDecklistNode *>(root->findChild(zoneName))) {
         QString groupCriteria = extractGroupCriteriaValue(info, activeGroupCriteria);
-        if (auto *groupNode = dynamic_cast<InnerDecklistNode *>(zoneNode->findChild(groupCriteria))) {
+        if (auto *groupNode = DeckListModelCustomZones::findGroupChild(zoneNode, groupCriteria)) {
             if (auto *card = dynamic_cast<DecklistModelCardNode *>(
                     groupNode->findCardChildByNameProviderIdAndNumber(cardName, providerId, cardNumber))) {
                 return card;
@@ -486,6 +487,26 @@ QModelIndex DeckListModel::addCard(const ExactCard &card, const QString &zoneNam
         // Custom zone: cards live flat inside the zone.
         cardParent = customZoneNode;
     } else {
+        // Not present in the shadow tree. The deck tree may still hold a custom
+        // zone that has not been mirrored (callers can add a zone and then a
+        // card without a rebuild). Check before falling back to creating a
+        // top-level zone the deck does not actually have.
+        auto *listRoot = deckList->getTree()->getRoot();
+        bool hasDeckZone = false;
+        for (int i = 0; i < listRoot->size(); ++i) {
+            if (auto *boardZone = dynamic_cast<InnerDecklistNode *>(listRoot->at(i))) {
+                if (boardZone->findChild(zoneName)) {
+                    hasDeckZone = true;
+                    break;
+                }
+            }
+        }
+
+        if (hasDeckZone) {
+            rebuildTree();
+            return addCard(card, zoneName);
+        }
+
         // Unknown zone: create a top-level zone (legacy behavior).
         QString groupCriteria = extractGroupCriteriaValue(cardInfo, activeGroupCriteria);
         auto *newZone = createNodeIfNeeded(zoneName, root);

libcockatrice_models/libcockatrice/models/deck_list/deck_list_model_custom_zones.cpp

@@ -14,26 +14,55 @@ bool isCustomZone(const AbstractDecklistNode *node)
     return dynamic_cast<const DecklistModelSubZoneNode *>(node) != nullptr;
 }
 
+namespace
+{
+
+/**
+ * @brief Flattens every card under @p zone into @p shadowZone, preserving order.
+ *
+ * Custom zones mirror as a single row level: cards nested in sub-zones of any
+ * depth are added as direct children of the mirrored zone so no card is left
+ * without a model row.
+ */
+void flattenCards(const InnerDecklistNode *zone, InnerDecklistNode *shadowZone)
+{
+    for (int k = 0; k < zone->size(); k++) {
+        if (auto *zoneCard = dynamic_cast<DecklistCardNode *>(zone->at(k))) {
+            new DecklistModelCardNode(zoneCard, shadowZone);
+        } else if (auto *subZone = dynamic_cast<const InnerDecklistNode *>(zone->at(k))) {
+            flattenCards(subZone, shadowZone);
+        }
+    }
+}
+
+} // namespace
+
 void mirrorCustomZones(const InnerDecklistNode *deckBoardZone, InnerDecklistNode *shadowBoardZone)
 {
     for (int j = 0; j < deckBoardZone->size(); j++) {
-        auto *customCard = dynamic_cast<DecklistCardNode *>(deckBoardZone->at(j));
-        if (customCard) {
-            continue;
-        }
-
         auto *customZone = dynamic_cast<const InnerDecklistNode *>(deckBoardZone->at(j));
         if (!customZone) {
             continue;
         }
 
         auto *shadowZone = new DecklistModelSubZoneNode(customZone->getName(), shadowBoardZone);
-        for (int k = 0; k < customZone->size(); k++) {
-            if (auto *zoneCard = dynamic_cast<DecklistCardNode *>(customZone->at(k))) {
-                new DecklistModelCardNode(zoneCard, shadowZone);
-            }
+        flattenCards(customZone, shadowZone);
+    }
+}
+
+InnerDecklistNode *findGroupChild(InnerDecklistNode *parent, const QString &name)
+{
+    for (int i = 0; i < parent->size(); i++) {
+        AbstractDecklistNode *child = parent->at(i);
+        if (isCustomZone(child)) {
+            continue;
+        }
+        auto *group = dynamic_cast<InnerDecklistNode *>(child);
+        if (group && group->getName() == name) {
+            return group;
         }
     }
+    return nullptr;
 }
 
 DecklistModelSubZoneNode *findSubZoneByName(InnerDecklistNode *root, const QString &zoneName)

libcockatrice_models/libcockatrice/models/deck_list/deck_list_model_custom_zones.h

@@ -43,6 +43,21 @@ namespace DeckListModelCustomZones
  */
 [[nodiscard]] bool isCustomZone(const AbstractDecklistNode *node);
 
+/**
+ * @brief Finds a criteria-group child of @p parent by name, skipping custom zones.
+ *
+ * The shadow tree keeps criteria groups and mirrored custom zones as siblings
+ * under a board zone, and `InnerDecklistNode::findChild` matches both by name.
+ * Group lookups must not resolve a custom zone that happens to share the group
+ * name (e.g. a zone called "Creature"), so this searches only non-custom
+ * children.
+ *
+ * @param parent The shadow node whose children are searched.
+ * @param name The group name to find.
+ * @return The matching group node, or nullptr if none exists.
+ */
+[[nodiscard]] InnerDecklistNode *findGroupChild(InnerDecklistNode *parent, const QString &name);
+
 /**
  * @brief Mirrors the custom zones of a deck board zone into its shadow board node.
  *

tests/deck_list_model/CMakeLists.txt

@@ -1,4 +1,4 @@
-add_executable(deck_list_model_custom_zones_test deck_list_model_custom_zones_test.cpp)
+add_executable(deck_list_model_custom_zones_test ${VERSION_STRING_CPP} deck_list_model_custom_zones_test.cpp)
 
 if(NOT GTEST_FOUND)
   add_dependencies(deck_list_model_custom_zones_test gtest)

tests/deck_list_model/deck_list_model_custom_zones_test.cpp

@@ -129,6 +129,51 @@ TEST(DeckListModelCustomZones, MirrorCustomZonesWithNoCustomZonesIsNoop)
     EXPECT_EQ(shadowBoard->size(), 0);
 }
 
+TEST(DeckListModelCustomZones, MirrorCustomZonesFlattensNestedSubzones)
+{
+    // Cards deeper than one level under a custom zone still get a model row.
+    auto *deckBoard = new InnerDecklistNode(DECK_ZONE_MAIN);
+    auto *deckZone = new InnerDecklistNode("Removal", deckBoard);
+    auto *deckCard1 = new DecklistCardNode("Bolt", 1, deckZone);
+    auto *deeper = new InnerDecklistNode("Deeper", deckZone);
+    auto *deckCard2 = new DecklistCardNode("Swords", 1, deeper);
+
+    InnerDecklistNode shadowRoot;
+    auto *shadowBoard = new InnerDecklistNode(DECK_ZONE_MAIN, &shadowRoot);
+
+    DeckListModelCustomZones::mirrorCustomZones(deckBoard, shadowBoard);
+
+    ASSERT_EQ(shadowBoard->size(), 1);
+    auto *shadowZone = dynamic_cast<DecklistModelSubZoneNode *>(shadowBoard->at(0));
+    ASSERT_NE(shadowZone, nullptr);
+    EXPECT_EQ(shadowZone->getName(), QString("Removal"));
+
+    // Both cards are flattened into the mirrored zone, preserving order.
+    ASSERT_EQ(shadowZone->size(), 2);
+    auto *shadowCard1 = dynamic_cast<DecklistModelCardNode *>(shadowZone->at(0));
+    auto *shadowCard2 = dynamic_cast<DecklistModelCardNode *>(shadowZone->at(1));
+    ASSERT_NE(shadowCard1, nullptr);
+    ASSERT_NE(shadowCard2, nullptr);
+    EXPECT_EQ(shadowCard1->getDataNode(), deckCard1);
+    EXPECT_EQ(shadowCard2->getDataNode(), deckCard2);
+}
+
+// =====================================================================================================================
+// findGroupChild
+// =====================================================================================================================
+
+TEST(DeckListModelCustomZones, FindGroupChildSkipsCustomZones)
+{
+    InnerDecklistNode root;
+    auto *board = new InnerDecklistNode(DECK_ZONE_MAIN, &root);
+    auto *group = new InnerDecklistNode("Creature", board);
+    new DecklistModelSubZoneNode("Creature", board);
+
+    EXPECT_EQ(DeckListModelCustomZones::findGroupChild(board, "Creature"), group);
+    EXPECT_EQ(DeckListModelCustomZones::findGroupChild(board, "Missing"), nullptr);
+    EXPECT_EQ(DeckListModelCustomZones::findGroupChild(&root, DECK_ZONE_MAIN), board);
+}
+
 // =====================================================================================================================
 // sortWithCustomZonesLast
 // =====================================================================================================================
@@ -223,3 +268,9 @@ TEST(DeckListModelCustomZones, SortPlainNodeDoesNotReorderCustomZones)
     EXPECT_EQ(mapping[1].first, 0);
     EXPECT_EQ(mapping[1].second, 1);
 }
+
+int main(int argc, char **argv)
+{
+    ::testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}

tests/deck_list_model/deck_list_model_zone_integration_test.cpp

@@ -1,4 +1,8 @@
 #include <gtest/gtest.h>
+#include <libcockatrice/card/card_info.h>
+#include <libcockatrice/card/database/card_database_manager.h>
+#include <libcockatrice/card/game_specific_terms.h>
+#include <libcockatrice/card/printing/exact_card.h>
 #include <libcockatrice/deck_list/deck_list.h>
 #include <libcockatrice/deck_list/deck_list_node_tree.h>
 #include <libcockatrice/deck_list/tree/deck_list_card_node.h>
@@ -25,6 +29,32 @@ int totalCustomZoneRows(const DeckListModel &model)
     return count;
 }
 
+QModelIndex findBoardIndex(const DeckListModel &model, const QString &boardName)
+{
+    for (int r = 0; r < model.rowCount(QModelIndex()); ++r) {
+        const QModelIndex idx = model.index(r, 0, QModelIndex());
+        if (idx.data(DeckRoles::IsCardRole).toBool()) {
+            continue;
+        }
+        const QString name = idx.sibling(idx.row(), DeckListModelColumns::CARD_NAME).data(Qt::EditRole).toString();
+        if (name == boardName) {
+            return idx;
+        }
+    }
+    return {};
+}
+
+QModelIndex findZoneRow(const DeckListModel &model, const QModelIndex &board)
+{
+    for (int r = 0; r < model.rowCount(board); ++r) {
+        const QModelIndex child = model.index(r, 0, board);
+        if (child.data(DeckRoles::IsCustomZoneRole).toBool()) {
+            return child;
+        }
+    }
+    return {};
+}
+
 } // namespace
 
 // The "Add to Zone" combobox/submenu lists getCustomZoneNames(), which reads the
@@ -69,3 +99,148 @@ TEST(DeckListModelZoneIntegration, RebuildTreeMirrorsEachZoneOnce)
     EXPECT_EQ(model.getCustomZoneNames(DECK_ZONE_MAIN), (QStringList{"Removal", "Utility"}));
     EXPECT_EQ(totalCustomZoneRows(model), 2);
 }
+
+// =====================================================================================================================
+// Model behaviour: addCard routing, findCard lookup, removeRows guard, empty-zone survival.
+// =====================================================================================================================
+
+TEST(DeckListModelZoneIntegration, AddCardRoutesIntoMirroredCustomZone)
+{
+    QSharedPointer<DeckList> deck(new DeckList());
+    DeckListModel model(nullptr, deck);
+    auto *tree = deck->getTree();
+
+    ASSERT_NE(tree->addCustomZone(DECK_ZONE_MAIN, "Removal"), nullptr);
+    model.rebuildTree();
+
+    QModelIndex added = model.addCard(ExactCard(CardInfo::newInstance("Lightning Bolt")), "Removal");
+    ASSERT_TRUE(added.isValid());
+
+    // The card is a direct child of the mirrored custom zone, not a new top-level zone.
+    const QModelIndex zoneParent = added.parent();
+    ASSERT_TRUE(zoneParent.isValid());
+    EXPECT_TRUE(zoneParent.data(DeckRoles::IsCustomZoneRole).toBool());
+    EXPECT_EQ(zoneParent.sibling(zoneParent.row(), DeckListModelColumns::CARD_NAME).data(Qt::DisplayRole).toString(),
+              QString("Removal"));
+
+    // No "Removal" top-level zone appeared in the deck tree.
+    auto *listRoot = tree->getRoot();
+    bool topLevelRemoval = false;
+    for (int i = 0; i < listRoot->size(); ++i) {
+        if (auto *zone = dynamic_cast<InnerDecklistNode *>(listRoot->at(i))) {
+            topLevelRemoval |= zone->getName() == "Removal";
+        }
+    }
+    EXPECT_FALSE(topLevelRemoval);
+}
+
+TEST(DeckListModelZoneIntegration, AddCardToUnmirroredCustomZoneRebuildsNotCreatesTopLevel)
+{
+    QSharedPointer<DeckList> deck(new DeckList());
+    DeckListModel model(nullptr, deck);
+    auto *tree = deck->getTree();
+
+    // The zone exists on the deck tree but the shadow tree has never mirrored it.
+    ASSERT_NE(tree->addCustomZone(DECK_ZONE_MAIN, "Removal"), nullptr);
+
+    QModelIndex added = model.addCard(ExactCard(CardInfo::newInstance("Lightning Bolt")), "Removal");
+    ASSERT_TRUE(added.isValid());
+
+    const QModelIndex zoneParent = added.parent();
+    ASSERT_TRUE(zoneParent.isValid());
+    EXPECT_TRUE(zoneParent.data(DeckRoles::IsCustomZoneRole).toBool());
+    EXPECT_EQ(zoneParent.sibling(zoneParent.row(), DeckListModelColumns::CARD_NAME).data(Qt::DisplayRole).toString(),
+              QString("Removal"));
+}
+
+TEST(DeckListModelZoneIntegration, AddCardCreatesGroupSeparatelyFromSameNamedZone)
+{
+    QSharedPointer<DeckList> deck(new DeckList());
+    DeckListModel model(nullptr, deck);
+    auto *tree = deck->getTree();
+
+    // A custom zone named exactly like a grouping criterion.
+    ASSERT_NE(tree->addCustomZone(DECK_ZONE_MAIN, "Creature"), nullptr);
+    model.rebuildTree();
+
+    CardInfoPtr bear = CardInfo::newInstance("Grizzly Bears");
+    bear->setProperty(Mtg::MainCardType, "Creature");
+
+    QModelIndex added = model.addCard(ExactCard(bear), DECK_ZONE_MAIN);
+    ASSERT_TRUE(added.isValid());
+
+    // The card lands in a *group* node called "Creature", not swallowed by the custom zone.
+    const QModelIndex groupParent = added.parent();
+    ASSERT_TRUE(groupParent.isValid());
+    EXPECT_FALSE(groupParent.data(DeckRoles::IsCustomZoneRole).toBool());
+    EXPECT_EQ(groupParent.sibling(groupParent.row(), DeckListModelColumns::CARD_NAME).data(Qt::DisplayRole).toString(),
+              QString("Creature"));
+
+    // The board keeps both rows: the "Creature" group and the "Creature" custom zone.
+    const QModelIndex boardIndex = groupParent.parent();
+    ASSERT_TRUE(boardIndex.isValid());
+    EXPECT_EQ(model.rowCount(boardIndex), 2);
+}
+
+TEST(DeckListModelZoneIntegration, FindCardResolvesCardInsideCustomZone)
+{
+    QSharedPointer<DeckList> deck(new DeckList());
+    DeckListModel model(nullptr, deck);
+    auto *tree = deck->getTree();
+
+    ASSERT_NE(tree->addCustomZone(DECK_ZONE_MAIN, "Removal"), nullptr);
+    model.rebuildTree();
+
+    // findCard resolves through the card database; register the card we add.
+    const QString cardName = "Swords to Plowshares";
+    CardInfoPtr info = CardInfo::newInstance(cardName);
+    CardDatabaseManager::getInstance()->addCard(info);
+
+    QModelIndex added = model.addCard(ExactCard(info), "Removal");
+    ASSERT_TRUE(added.isValid());
+
+    QModelIndex found = model.findCard(cardName, "Removal");
+    EXPECT_TRUE(found.isValid());
+    EXPECT_EQ(found, added);
+}
+
+TEST(DeckListModelZoneIntegration, RemoveRowsRefusesCustomZoneRow)
+{
+    QSharedPointer<DeckList> deck(new DeckList());
+    DeckListModel model(nullptr, deck);
+    auto *tree = deck->getTree();
+
+    ASSERT_NE(tree->addCustomZone(DECK_ZONE_MAIN, "Removal"), nullptr);
+    tree->addCard("Lightning Bolt", 2, DECK_ZONE_MAIN, -1);
+    model.rebuildTree();
+
+    const QModelIndex mainIndex = findBoardIndex(model, DECK_ZONE_MAIN);
+    ASSERT_TRUE(mainIndex.isValid());
+    const QModelIndex zoneRow = findZoneRow(model, mainIndex);
+    ASSERT_TRUE(zoneRow.isValid());
+
+    EXPECT_FALSE(model.removeRow(zoneRow.row(), zoneRow.parent()));
+    EXPECT_EQ(model.rowCount(mainIndex), 2); // the zone survives, alongside the card group
+}
+
+TEST(DeckListModelZoneIntegration, EmptyCustomZoneSurvivesMirrorAndPruning)
+{
+    QSharedPointer<DeckList> deck(new DeckList());
+    DeckListModel model(nullptr, deck);
+    auto *tree = deck->getTree();
+
+    // An empty custom zone must be mirrored (the stack deliberately keeps it alive).
+    ASSERT_NE(tree->addCustomZone(DECK_ZONE_MAIN, "Removal"), nullptr);
+    model.rebuildTree();
+
+    const QModelIndex mainIndex = findBoardIndex(model, DECK_ZONE_MAIN);
+    ASSERT_TRUE(mainIndex.isValid());
+    EXPECT_EQ(model.rowCount(mainIndex), 1);
+    EXPECT_TRUE(findZoneRow(model, mainIndex).isValid());
+}
+
+int main(int argc, char **argv)
+{
+    ::testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}