Replace Yes/No text with Mulligan/Keep text on mulligan answer buttons to make options more clear.

Mage.Client/src/main/java/mage/client/game/FeedbackPanel.java

@@ -203,9 +203,15 @@ public class FeedbackPanel extends javax.swing.JPanel {
 
     private void handleOptions(Map<String, Serializable> options) {
         if (options != null) {
+            if (options.containsKey("UI.left.btn.text")) {
+                String text = (String) options.get("UI.left.btn.text");
+                this.btnLeft.setText(text);
+                this.helper.setLeft(text, true);
+            }
             if (options.containsKey("UI.right.btn.text")) {
-                this.btnRight.setText((String) options.get("UI.right.btn.text"));
+                String text = (String) options.get("UI.right.btn.text");
-                this.helper.setRight((String) options.get("UI.right.btn.text"), true);
+                this.btnRight.setText(text);
+                this.helper.setRight(text, true);
             }
             if (options.containsKey("dialog")) {
                 connectedDialog = (MageDialog) options.get("dialog");

Mage.Client/src/main/java/mage/client/game/HelperPanel.java

@@ -323,6 +323,13 @@ public class HelperPanel extends JPanel {
         this.btnUndo.setVisible(enabled);
     }
 
+    public void setLeft(String text, boolean visible) {
+        this.btnLeft.setVisible(visible);
+        if (!text.isEmpty()) {
+            this.btnLeft.setText(text);
+        }
+    }
+
     public void setRight(String txtRight, boolean rightVisible) {
         this.btnRight.setVisible(rightVisible);
         if (!txtRight.isEmpty()) {

Mage.Server.Plugins/Mage.Player.Human/src/mage/player/human/HumanPlayer.java

@@ -160,9 +160,13 @@ public class HumanPlayer extends PlayerImpl {
         updateGameStatePriority("chooseMulligan", game);
         int nextHandSize = game.mulliganDownTo(playerId);
         do {
-            game.fireAskPlayerEvent(playerId, new MessageToClient("Mulligan "
+            String message = "Mulligan "
                     + (getHand().size() > nextHandSize ? "down to " : "for free, draw ")
-                    + nextHandSize + (nextHandSize == 1 ? " card?" : " cards?")), null);
+                    + nextHandSize + (nextHandSize == 1 ? " card?" : " cards?");
+            Map<String, Serializable> options = new HashMap<>();
+            options.put("UI.left.btn.text", "Mulligan");
+            options.put("UI.right.btn.text", "Keep");
+            game.fireAskPlayerEvent(playerId, new MessageToClient(message), null, options);
             waitForResponse(game);
         } while (response.getBoolean() == null && !abort);
         if (!abort) {

Mage/src/main/java/mage/game/Game.java

@@ -237,6 +237,8 @@ public interface Game extends MageItem, Serializable {
 
     void fireAskPlayerEvent(UUID playerId, MessageToClient message, Ability source);
 
+    void fireAskPlayerEvent(UUID playerId, MessageToClient message, Ability source, Map<String, Serializable> options);
+
     void fireChooseChoiceEvent(UUID playerId, Choice choice);
 
     void fireSelectTargetEvent(UUID playerId, MessageToClient message, Set<UUID> targets, boolean required, Map<String, Serializable> options);

Mage/src/main/java/mage/game/GameImpl.java

@@ -2018,10 +2018,15 @@ public abstract class GameImpl implements Game, Serializable {
 
     @Override
     public void fireAskPlayerEvent(UUID playerId, MessageToClient message, Ability source) {
+        fireAskPlayerEvent(playerId, message, source, null);
+    }
+
+    @Override
+    public void fireAskPlayerEvent(UUID playerId, MessageToClient message, Ability source, Map<String, Serializable> options) {
         if (simulation) {
             return;
         }
-        playerQueryEventSource.ask(playerId, message.getMessage(), source, addMessageToOptions(message, null));
+        playerQueryEventSource.ask(playerId, message.getMessage(), source, addMessageToOptions(message, options));
     }
 
     @Override