[Client] Expose custom zone management in the deck editor

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/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<void()> &newZoneHandler)
+{
+    zoneMenuProvider = provider;
+    this->newZoneHandler = newZoneHandler;
+}
+
 void CardDatabaseView::updateCard(const QModelIndex &current, const QModelIndex & /*previous*/)
 {
     if (!current.isValid()) {
@@ -142,6 +149,40 @@ 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"));
+        for (const QString &boardName :
+             {QString(DECK_ZONE_MAIN), QString(DECK_ZONE_SIDE), QString(DECK_ZONE_MAYBEBOARD)}) {
+            QAction *action = addToZoneMenu->addAction(InnerDecklistNode::visibleNameFromName(boardName));
+            connect(action, &QAction::triggered, this,
+                    [this, card, boardName] { emit cardAdded(card->getName(), boardName); });
+        }
+
+        bool anyCustomZone = false;
+        const auto zoneBoards = zoneMenuProvider();
+        for (const auto &zoneBoard : zoneBoards) {
+            const QString &boardName = zoneBoard.first;
+            const QStringList &customZones = zoneBoard.second;
+            if (customZones.isEmpty()) {
+                continue;
+            }
+            anyCustomZone = true;
+            QMenu *boardSubmenu = addToZoneMenu->addMenu(InnerDecklistNode::visibleNameFromName(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 (anyCustomZone) {
+            addToZoneMenu->addSeparator();
+        }
+
+        QAction *newZoneAction = addToZoneMenu->addAction(tr("Create &new zone..."));
+        connect(newZoneAction, &QAction::triggered, this, [this] { newZoneHandler(); });
+    }
+
     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 +20,12 @@ 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.
+    std::function<void()> newZoneHandler;
+
 public:
     explicit CardDatabaseView(QWidget *parent, CardDatabaseDisplayModel *model);
 
@@ -33,6 +40,16 @@ 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 Invoked when the user chooses "New zone..." in the submenu
+     */
+    void setZoneMenuProvider(const std::function<QList<QPair<QString, QStringList>>()> &provider,
+                             const std::function<void()> &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 +22,26 @@ 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 :
+                 {QString(DECK_ZONE_MAIN), QString(DECK_ZONE_SIDE), QString(DECK_ZONE_MAYBEBOARD)}) {
+                result.append({boardName, deckListModel->getCustomZoneNames(boardName)});
+            }
+            return result;
+        },
+        [this, deckEditor] {
+            QString boardName;
+            const QString zoneName = promptForNewZone(this, {}, &boardName, [deckEditor](const QString &candidate) {
+                return deckEditor->deckStateManager->validateNewZoneName(candidate);
+            });
+            if (!zoneName.isEmpty()) {
+                deckEditor->deckStateManager->createCustomZone(boardName, 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 +775,142 @@ 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);
+
+    if (isCardRow) {
+        addMoveToZoneMenu(&menu, sourceIndex);
+        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] {
+            const QString newName = promptForRename(this, zoneName, [this](const QString &candidate) {
+                return 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"));
+        deleteAction->setEnabled(!getModel()->hasChildren(sourceIndex));
+        deleteAction->setStatusTip(tr("Move or remove all cards first."));
+        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 auto moveToZone = [this, sourceCardIndex](const QString &targetZoneName) {
+        deckStateManager->moveCardToZone(sourceCardIndex, targetZoneName);
+    };
+
+    for (const QString &boardName : {QString(DECK_ZONE_MAIN), QString(DECK_ZONE_SIDE), QString(DECK_ZONE_MAYBEBOARD)}) {
+        QAction *action = menu->addAction(InnerDecklistNode::visibleNameFromName(boardName));
+        connect(action, &QAction::triggered, this, [moveToZone, boardName] { moveToZone(boardName); });
+    }
+
+    const auto tree = deckStateManager->getDeckListShared()->getTree();
+    bool anyCustomZone = false;
+    for (const QString &boardName : {QString(DECK_ZONE_MAIN), QString(DECK_ZONE_SIDE), QString(DECK_ZONE_MAYBEBOARD)}) {
+        QList<const InnerDecklistNode *> customZones = tree->getCustomZones(boardName);
+        if (customZones.isEmpty()) {
+            continue;
+        }
+        anyCustomZone = true;
+        QMenu *boardSubmenu = menu->addMenu(InnerDecklistNode::visibleNameFromName(boardName));
+        for (const auto *customZone : customZones) {
+            QAction *action = boardSubmenu->addAction(customZone->getName());
+            connect(action, &QAction::triggered, this, [moveToZone, customZone] { moveToZone(customZone->getName()); });
+        }
+    }
+
+    if (anyCustomZone) {
+        menu->addSeparator();
+    }
+
+    addNewZoneAction(menu);
+}
+
+void DeckEditorDeckDockWidget::addChangeBoardMenu(QMenu *menu, const QString &zoneName)
+{
+    const auto tree = deckStateManager->getDeckListShared()->getTree();
+    for (const QString &boardName : {QString(DECK_ZONE_MAIN), QString(DECK_ZONE_SIDE), QString(DECK_ZONE_MAYBEBOARD)}) {
+        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] {
+        QString boardName;
+        const QString zoneName = promptForNewZone(this, initialBoardName, &boardName, [this](const QString &candidate) {
+            return deckStateManager->validateNewZoneName(candidate);
+        });
+        if (!zoneName.isEmpty()) {
+            deckStateManager->createCustomZone(boardName, 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 +103,10 @@ private:
     [[nodiscard]] QModelIndexList getSelectedCardNodeSourceIndices() const;
     void offsetCountAtIndex(const QModelIndex &idx, bool isIncrement);
 
+    void addMoveToZoneMenu(QMenu *menu, const QModelIndex &sourceCardIndex);
+    void addChangeBoardMenu(QMenu *menu, const QString &zoneName);
+    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 +308,187 @@ 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 : {QString(DECK_ZONE_MAIN), QString(DECK_ZONE_SIDE), QString(DECK_ZONE_MAYBEBOARD)}) {
+        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();
+
+    // Top-level zones (boards and legacy zones) claim their names too.
+    for (int i = 0; i < tree->getRoot()->size(); i++) {
+        if (tree->getRoot()->at(i)->getName() == trimmedZoneName) {
+            return tr("A zone with this name already exists.");
+        }
+    }
+
+    // Custom zone names are unique across the whole deck.
+    for (const QString &board : {QString(DECK_ZONE_MAIN), QString(DECK_ZONE_SIDE), QString(DECK_ZONE_MAYBEBOARD)}) {
+        for (const auto *customZone : tree->getCustomZones(board)) {
+            if (customZone->getName() == trimmedZoneName) {
+                return tr("A zone with this name already exists.");
+            }
+        }
+    }
+
+    return {};
+}
+
 bool DeckStateManager::offsetCountAtIndex(const QModelIndex &idx, int offset)
 {
     if (!idx.isValid()) {
@@ -367,6 +549,21 @@ 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();
+        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 +1,139 @@
+#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->setStyleSheet("color: palette(bright-text);");
+    errorLabel->hide();
+
+    boardLabel = new QLabel(this);
+    boardCombo = new QComboBox(this);
+    for (const QString &boardName : {QString(DECK_ZONE_MAIN), QString(DECK_ZONE_SIDE), QString(DECK_ZONE_MAYBEBOARD)}) {
+        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);
+    }
+    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 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 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);
+
+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;
+};
+
+/**
+ * @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
+ */
+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
+ */
+QString promptForRename(QWidget *parent,
+                        const QString &currentZoneName,
+                        const std::function<QString(const QString &)> &nameValidator = {});
+
+#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);
+    connect(tabContainer, &TabDeckEditorVisualTabWidget::newZoneRequested, this, &TabDeckEditorVisual::createNewZone);
 
     centralFrame->addWidget(tabContainer);
     setCentralWidget(centralWidget);
@@ -269,6 +271,18 @@ bool TabDeckEditorVisual::actSaveDeckAs()
     return result;
 }
 
+/** @brief Prompts for and creates a new custom deck zone. */
+void TabDeckEditorVisual::createNewZone()
+{
+    QString boardName;
+    const QString zoneName = promptForNewZone(this, {}, &boardName, [this](const QString &candidate) {
+        return deckStateManager->validateNewZoneName(candidate);
+    });
+    if (!zoneName.isEmpty()) {
+        deckStateManager->createCustomZone(boardName, 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 +165,11 @@ public slots:
      */
     bool actSaveDeckAs() override;
 
+    /**
+     * @brief Prompts for and creates a new custom deck zone.
+     */
+    void createNewZone();
+
 private:
     /**
      * @brief Sets the deck for this tab and selects the sub-tab to open on

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

@@ -51,6 +51,8 @@ TabDeckEditorVisualTabWidget::TabDeckEditorVisualTabWidget(QWidget *parent,
             &TabDeckEditorVisualTabWidget::printingSelectorRequested);
     connect(visualDatabaseDisplay, &VisualDatabaseDisplayWidget::cardInfoRequested, this,
             &TabDeckEditorVisualTabWidget::cardInfoRequested);
+    connect(visualDatabaseDisplay, &VisualDatabaseDisplayWidget::newZoneRequested, this,
+            &TabDeckEditorVisualTabWidget::newZoneRequested);
 
     statsAnalyzer = new DeckListStatisticsAnalyzer(this, deckModel);
     statsAnalyzer->analyze();

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

@@ -133,6 +133,7 @@ signals:
     void edhrecRequested(const CardInfoPtr &cardInfo, bool isCommander);
     void printingSelectorRequested();
     void cardInfoRequested(const ExactCard &cardName);
+    void newZoneRequested();
 
 private:
     QVBoxLayout *layout;                  ///< Layout for tabs and controls.

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

@@ -89,6 +89,20 @@ 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(
+            [this, deckListModel]() -> QList<QPair<QString, QStringList>> {
+                QList<QPair<QString, QStringList>> result;
+                for (const QString &boardName :
+                     {QString(DECK_ZONE_MAIN), QString(DECK_ZONE_SIDE), QString(DECK_ZONE_MAYBEBOARD)}) {
+                    result.append({boardName, deckListModel->getCustomZoneNames(boardName)});
+                }
+                return result;
+            },
+            [this] { emit newZoneRequested(); });
+    }
+
     searchEdit->setTreeView(databaseView);
     searchEdit->installEventFilter(databaseView->getKeySignals());
 

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

@@ -78,6 +78,7 @@ signals:
     void edhrecRequested(const CardInfoPtr &cardInfo, bool isCommander);
     void printingSelectorRequested();
     void cardInfoRequested(const ExactCard &cardName);
+    void newZoneRequested();
 
 protected slots:
     void initialize();

libcockatrice_models/libcockatrice/models/deck_list/deck_list_model.cpp

@@ -68,6 +68,16 @@ void DeckListModel::rebuildTree()
 
             //! \todo Better sanity checking.
             if (currentCard == nullptr) {
+                // Custom zones nested under the board zone are mirrored as-is,
+                // with their cards as direct children (no further grouping).
+                if (auto *customZone = dynamic_cast<InnerDecklistNode *>(currentZone->at(j))) {
+                    auto *shadowZone = new DecklistModelSubZoneNode(customZone->getName(), node);
+                    for (int k = 0; k < customZone->size(); k++) {
+                        if (auto *customCard = dynamic_cast<DecklistCardNode *>(customZone->at(k))) {
+                            new DecklistModelCardNode(customCard, shadowZone);
+                        }
+                    }
+                }
                 continue;
             }
 
@@ -84,6 +94,13 @@ void DeckListModel::rebuildTree()
         }
     }
 
+    // The shadow tree was built in deck file order. Apply the active sort while
+    // the reset is still open so every consumer (tree view and visual editor)
+    // sees the canonical order from the start. sortShadowTree emits no signals,
+    // which is only valid before endResetModel closes the reset.
+    root->setSortMethod(lastKnownColumn == 0 ? DeckSortMethod::ByNumber : DeckSortMethod::ByName);
+    sortShadowTree(root, lastKnownOrder);
+
     endResetModel();
 
     refreshCardFormatLegalities();
@@ -154,6 +171,9 @@ QVariant DeckListModel::data(const QModelIndex &index, int role) const
             case DeckRoles::IsLegalRole:
                 return true;
 
+            case DeckRoles::IsCustomZoneRole:
+                return dynamic_cast<const DecklistModelSubZoneNode *>(group) != nullptr;
+
             default:
                 return {};
         }
@@ -190,6 +210,10 @@ QVariant DeckListModel::data(const QModelIndex &index, int role) const
             return card->getFormatLegality();
         }
 
+        case DeckRoles::IsCustomZoneRole: {
+            return false;
+        }
+
         default: {
             return {};
         }
@@ -327,6 +351,13 @@ bool DeckListModel::removeRows(int row, int count, const QModelIndex &parent)
         return false;
     }
 
+    // Custom zone rows are managed through the deck tree, never removed as model rows.
+    for (int i = 0; i < count; i++) {
+        if (dynamic_cast<DecklistModelSubZoneNode *>(node->at(row + i))) {
+            return false;
+        }
+    }
+
     beginRemoveRows(parent, row, row + count - 1);
     for (int i = 0; i < count; i++) {
         AbstractDecklistNode *toDelete = node->takeAt(row);
@@ -337,7 +368,8 @@ bool DeckListModel::removeRows(int row, int count, const QModelIndex &parent)
     }
     endRemoveRows();
 
-    if (node->empty() && (node != root)) {
+    // Empty criteria groups get pruned, but custom zones stay until explicitly deleted.
+    if (node->empty() && (node != root) && !dynamic_cast<DecklistModelSubZoneNode *>(node)) {
         removeRows(parent.row(), 1, parent.parent());
     } else {
         emitRecursiveUpdates(parent);
@@ -365,24 +397,41 @@ DecklistModelCardNode *DeckListModel::findCardNode(const QString &cardName,
                                                    const QString &providerId,
                                                    const QString &cardNumber) const
 {
-    InnerDecklistNode *zoneNode = dynamic_cast<InnerDecklistNode *>(root->findChild(zoneName));
-    if (!zoneNode) {
-        return nullptr;
-    }
-
     CardInfoPtr info = CardDatabaseManager::query()->getCardInfo(cardName);
     if (!info) {
         return nullptr;
     }
 
-    QString groupCriteria = extractGroupCriteriaValue(info, activeGroupCriteria);
-    InnerDecklistNode *groupNode = dynamic_cast<InnerDecklistNode *>(zoneNode->findChild(groupCriteria));
-    if (!groupNode) {
-        return nullptr;
+    // 1. Board zone lookup: search the criteria groups, then the custom zones
+    //    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 *card = dynamic_cast<DecklistModelCardNode *>(
+                    groupNode->findCardChildByNameProviderIdAndNumber(cardName, providerId, cardNumber))) {
+                return card;
+            }
+        }
+
+        for (auto *child : *zoneNode) {
+            auto *customZone = dynamic_cast<DecklistModelSubZoneNode *>(child);
+            if (!customZone) {
+                continue;
+            }
+            if (auto *card = dynamic_cast<DecklistModelCardNode *>(
+                    customZone->findCardChildByNameProviderIdAndNumber(cardName, providerId, cardNumber))) {
+                return card;
+            }
+        }
     }
 
-    return dynamic_cast<DecklistModelCardNode *>(
-        groupNode->findCardChildByNameProviderIdAndNumber(cardName, providerId, cardNumber));
+    // 2. Custom zone lookup by name (custom zone names are deck-unique).
+    if (auto *customZone = findSubZoneNodeByName(zoneName)) {
+        return dynamic_cast<DecklistModelCardNode *>(
+            customZone->findCardChildByNameProviderIdAndNumber(cardName, providerId, cardNumber));
+    }
+
+    return nullptr;
 }
 
 QModelIndex DeckListModel::findCard(const QString &cardName,
@@ -398,6 +447,25 @@ QModelIndex DeckListModel::findCard(const QString &cardName,
     return nodeToIndex(cardNode);
 }
 
+DecklistModelSubZoneNode *DeckListModel::findSubZoneNodeByName(const QString &zoneName) const
+{
+    for (int i = 0; i < root->size(); i++) {
+        auto *boardZone = dynamic_cast<InnerDecklistNode *>(root->at(i));
+        if (!boardZone) {
+            continue;
+        }
+
+        for (int j = 0; j < boardZone->size(); j++) {
+            auto *customZone = dynamic_cast<DecklistModelSubZoneNode *>(boardZone->at(j));
+            if (customZone && customZone->getName() == zoneName) {
+                return customZone;
+            }
+        }
+    }
+
+    return nullptr;
+}
+
 QModelIndex DeckListModel::addPreferredPrintingCard(const QString &cardName, const QString &zoneName, bool abAddAnyway)
 {
     ExactCard card = CardDatabaseManager::query()->getCard({cardName});
@@ -423,29 +491,43 @@ QModelIndex DeckListModel::addCard(const ExactCard &card, const QString &zoneNam
         return {};
     }
 
-    InnerDecklistNode *zoneNode = createNodeIfNeeded(zoneName, root);
-
     CardInfoPtr cardInfo = card.getCardPtr();
     PrintingInfo printingInfo = card.getPrinting();
 
-    QString groupCriteria = extractGroupCriteriaValue(cardInfo, activeGroupCriteria);
-    InnerDecklistNode *groupNode = createNodeIfNeeded(groupCriteria, zoneNode);
+    InnerDecklistNode *cardParent = nullptr;
 
-    const QModelIndex parentIndex = nodeToIndex(groupNode);
-    auto *cardNode = dynamic_cast<DecklistModelCardNode *>(groupNode->findCardChildByNameProviderIdAndNumber(
+    auto *boardNode = dynamic_cast<InnerDecklistNode *>(root->findChild(zoneName));
+    auto *customZoneNode = boardNode ? nullptr : findSubZoneNodeByName(zoneName);
+
+    if (boardNode) {
+        // Board zone: cards are grouped by the active criteria.
+        QString groupCriteria = extractGroupCriteriaValue(cardInfo, activeGroupCriteria);
+        cardParent = createNodeIfNeeded(groupCriteria, boardNode);
+    } else if (customZoneNode) {
+        // Custom zone: cards live flat inside the zone.
+        cardParent = customZoneNode;
+    } else {
+        // Unknown zone: create a top-level zone (legacy behavior).
+        QString groupCriteria = extractGroupCriteriaValue(cardInfo, activeGroupCriteria);
+        auto *newZone = createNodeIfNeeded(zoneName, root);
+        cardParent = createNodeIfNeeded(groupCriteria, newZone);
+    }
+
+    const QModelIndex parentIndex = nodeToIndex(cardParent);
+    auto *cardNode = dynamic_cast<DecklistModelCardNode *>(cardParent->findCardChildByNameProviderIdAndNumber(
         card.getName(), printingInfo.getUuid(), printingInfo.getProperty("num")));
     const auto cardSetName = printingInfo.getSet().isNull() ? "" : printingInfo.getSet()->getCorrectedShortName();
 
     bool cardNodeAdded = false;
     if (!cardNode) {
         // Determine the correct index
-        int insertRow = findSortedInsertRow(groupNode, cardInfo);
+        int insertRow = findSortedInsertRow(cardParent, cardInfo);
 
         auto *decklistCard = deckList->addCard(cardInfo->getName(), zoneName, insertRow, cardSetName,
                                                printingInfo.getProperty("num"), printingInfo.getProperty("uuid"));
 
         beginInsertRows(parentIndex, insertRow, insertRow);
-        cardNode = new DecklistModelCardNode(decklistCard, groupNode, insertRow);
+        cardNode = new DecklistModelCardNode(decklistCard, cardParent, insertRow);
         endInsertRows();
 
         cardNodeAdded = true;
@@ -576,21 +658,76 @@ QModelIndex DeckListModel::nodeToIndex(AbstractDecklistNode *node) const
     return createIndex(node->getParent()->indexOf(node), 0, node);
 }
 
+/**
+ * @brief Moves custom zones of a board zone after the criteria groups, stably.
+ *
+ * Sorting would interleave custom zones with criteria groups by name; custom
+ * zones must always stay after the groups, regardless of their names.
+ */
+void DeckListModel::shiftCustomZonesToEnd(InnerDecklistNode *boardZone)
+{
+    QList<AbstractDecklistNode *> customZones;
+    for (int i = boardZone->size() - 1; i >= 0; --i) {
+        if (dynamic_cast<DecklistModelSubZoneNode *>(boardZone->at(i))) {
+            customZones.prepend(boardZone->takeAt(i));
+        }
+    }
+    for (auto *customZone : customZones) {
+        boardZone->append(customZone);
+    }
+}
+
+/**
+ * @brief Sorts a freshly built shadow subtree without emitting model signals.
+ *
+ * Used by rebuildTree while the model reset is still open (emitting layout
+ * changes during a reset is invalid). Mirrors the reordering part of
+ * sortHelper: sort every node, then move board-level custom zones after groups.
+ */
+void DeckListModel::sortShadowTree(InnerDecklistNode *node, Qt::SortOrder order)
+{
+    node->sort(order);
+
+    if (node != root && node->getParent() == root) {
+        shiftCustomZonesToEnd(node);
+    }
+
+    for (int i = node->size() - 1; i >= 0; --i) {
+        if (auto *subNode = dynamic_cast<InnerDecklistNode *>(node->at(i))) {
+            sortShadowTree(subNode, order);
+        }
+    }
+}
+
 void DeckListModel::sortHelper(InnerDecklistNode *node, Qt::SortOrder order)
 {
     // Sort children of node and save the information needed to
     // update the list of persistent indexes.
     QVector<QPair<int, int>> sortResult = node->sort(order);
 
+    // For board zones, custom zones must stay after the criteria groups,
+    // regardless of their names. Shift them to the end (stable).
+    QHash<AbstractDecklistNode *, int> rowAfterSort;
+    bool isBoardZone = (node != root) && (node->getParent() == root);
+    if (isBoardZone) {
+        for (int i = 0; i < node->size(); ++i) {
+            rowAfterSort.insert(node->at(i), i);
+        }
+        shiftCustomZonesToEnd(node);
+    }
+
     QModelIndexList from, to;
     int columns = columnCount();
-    for (int i = sortResult.size() - 1; i >= 0; --i) {
-        const int fromRow = sortResult[i].first;
-        const int toRow = sortResult[i].second;
-        AbstractDecklistNode *temp = node->at(toRow);
+    for (int newRow = 0; newRow < node->size(); ++newRow) {
+        AbstractDecklistNode *temp = node->at(newRow);
+        int preSortRow = sortResult.value(newRow).first;
+        if (isBoardZone) {
+            const int rowAfterSortOfNode = rowAfterSort.value(temp, newRow);
+            preSortRow = sortResult.value(rowAfterSortOfNode).first;
+        }
         for (int j = 0; j < columns; ++j) {
-            from << createIndex(fromRow, j, temp);
-            to << createIndex(toRow, j, temp);
+            from << createIndex(preSortRow, j, temp);
+            to << createIndex(newRow, j, temp);
         }
     }
     changePersistentIndexList(from, to);
@@ -704,6 +841,15 @@ QList<QString> DeckListModel::getZones() const
     return zones;
 }
 
+QStringList DeckListModel::getCustomZoneNames(const QString &boardZoneName) const
+{
+    QStringList zoneNames;
+    for (const auto *customZone : deckList->getTree()->getCustomZones(boardZoneName)) {
+        zoneNames.append(customZone->getName());
+    }
+    return zoneNames;
+}
+
 static int maxAllowedForLegality(const FormatRules &format, const QString &legality)
 {
     for (const AllowedCount &c : format.allowedCounts) {

libcockatrice_models/libcockatrice/models/deck_list/deck_list_model.h

@@ -30,7 +30,8 @@ enum
 {
     IsCardRole = Qt::UserRole + 1, /**< Indicates whether the item represents a card. */
     DepthRole,                     /**< Depth level within the deck's grouping hierarchy. */
-    IsLegalRole                    /**< Whether the card is legal in the current deck format. */
+    IsLegalRole,                   /**< Whether the card is legal in the current deck format. */
+    IsCustomZoneRole               /**< Whether the item represents a custom zone nested under a board zone. */
 };
 } // namespace DeckRoles
 
@@ -190,6 +191,21 @@ public:
     }
 };
 
+/**
+ * @class DecklistModelSubZoneNode
+ * @ingroup DeckModels
+ * @brief Model node representing a custom zone nested under a board zone.
+ *
+ * Custom zones group cards by user-defined names (e.g. "Removal", "Utility")
+ * inside a board zone. They are mirrored from the underlying deck tree so that
+ * they can be told apart from criteria group nodes.
+ */
+class DecklistModelSubZoneNode : public InnerDecklistNode
+{
+public:
+    using InnerDecklistNode::InnerDecklistNode;
+};
+
 /**
  * @class DeckListModel
  * @ingroup DeckModels
@@ -391,6 +407,14 @@ public:
      */
     [[nodiscard]] QList<QString> getZones() const;
 
+    /**
+     * @brief Gets the names of the custom zones nested under the given board zone.
+     *
+     * @param boardZoneName The board zone to query (main/side/maybeboard)
+     * @return The custom zone names, in deck order
+     */
+    [[nodiscard]] QStringList getCustomZoneNames(const QString &boardZoneName) const;
+
 private:
     QSharedPointer<DeckList> deckList; /**< Pointer to the decklist providing the underlying data. */
     InnerDecklistNode *root;           /**< Root node of the model tree. */
@@ -405,6 +429,16 @@ private:
                                                       const QString &providerId = "",
                                                       const QString &cardNumber = "") const;
 
+    /**
+     * @brief Finds a custom zone node in the model tree by name.
+     *
+     * Custom zone names are unique across the whole deck.
+     *
+     * @param zoneName Name of the custom zone.
+     * @return The custom zone node, or nullptr if not found.
+     */
+    [[nodiscard]] DecklistModelSubZoneNode *findSubZoneNodeByName(const QString &zoneName) const;
+
     /**
      * @brief Determines the sorted insertion row for a card.
      * @param parent The parent node where the card will be inserted.
@@ -427,6 +461,8 @@ private:
     void emitRecursiveUpdates(const QModelIndex &index);
 
     void sortHelper(InnerDecklistNode *node, Qt::SortOrder order);
+    void sortShadowTree(InnerDecklistNode *node, Qt::SortOrder order);
+    void shiftCustomZonesToEnd(InnerDecklistNode *boardZone);
 
     template <typename T> T getNode(const QModelIndex &index) const
     {