diff --git a/Mage.Client/src/main/java/mage/client/cards/Cards.java b/Mage.Client/src/main/java/mage/client/cards/Cards.java
index d79ed7c1e9..cff58b5614 100644
--- a/Mage.Client/src/main/java/mage/client/cards/Cards.java
+++ b/Mage.Client/src/main/java/mage/client/cards/Cards.java
@@ -183,6 +183,7 @@
              if (card instanceof StackAbilityView) {
                  // replace ability by original card
                  CardView tmp = ((StackAbilityView) card).getSourceCard();
+                 // sync settings
                  tmp.overrideRules(card.getRules());
                  tmp.setChoosable(card.isChoosable());
                  tmp.setPlayableStats(card.getPlayableStats().copy());
@@ -191,6 +192,9 @@
                  tmp.overrideTargets(card.getTargets());
                  tmp.overrideId(card.getId());
                  tmp.setAbilityType(card.getAbilityType());
+                 // sync card icons
+                 tmp.getCardIcons().clear();
+                 tmp.getCardIcons().addAll(card.getCardIcons());
                  card = tmp;
              } else {
                  card.setAbilityType(null);
diff --git a/Mage.Common/src/main/java/mage/view/StackAbilityView.java b/Mage.Common/src/main/java/mage/view/StackAbilityView.java
index c9de06d7f6..74142d11d9 100644
--- a/Mage.Common/src/main/java/mage/view/StackAbilityView.java
+++ b/Mage.Common/src/main/java/mage/view/StackAbilityView.java
@@ -3,9 +3,11 @@ package mage.view;
 import mage.MageObject;
 import mage.abilities.Mode;
 import mage.abilities.Modes;
+import mage.abilities.dynamicvalue.common.ManacostVariableValue;
 import mage.abilities.effects.Effect;
 import mage.abilities.hint.Hint;
 import mage.abilities.hint.HintUtils;
+import mage.abilities.icon.other.VariableCostCardIcon;
 import mage.cards.Card;
 import mage.constants.AbilityType;
 import mage.constants.CardType;
@@ -28,7 +30,7 @@ public class StackAbilityView extends CardView {
     private static final long serialVersionUID = 1L;
 
     // in GUI: that's view will be replaced by sourceCard, so don't forget to sync settings like
-    // selectable, chooseable, etc. Search by getSourceCard
+    // selectable, chooseable, card icons etc. Search by getSourceCard
     private final CardView sourceCard;
 
     public StackAbilityView(Game game, StackAbility ability, String sourceName, CardView sourceCard) {
@@ -73,6 +75,13 @@ public class StackAbilityView extends CardView {
         this.counters = sourceCard.getCounters();
 
         updateTargets(game, ability);
+
+        // card icons (warning, it must be synced in gui dialogs with replaced card, see comments at the start of the file)
+        // cost x
+        if (ability.getManaCostsToPay().containsX()) {
+            int costX = ManacostVariableValue.REGULAR.calculate(game, ability, null);
+            this.cardIcons.add(new VariableCostCardIcon(costX));
+        }
     }
 
     private void updateTargets(Game game, StackAbility ability) {
@@ -108,7 +117,7 @@ public class StackAbilityView extends CardView {
             }
         }
         if (!names.isEmpty()) {
-            getRules().add("<i>Related objects: " + names.toString() + "</i>");
+            getRules().add("<i>Related objects: " + names + "</i>");
         }
 
         // show for modal ability, which mode was choosen
diff --git a/Mage.Tests/src/test/java/org/mage/test/serverside/CardIconsTest.java b/Mage.Tests/src/test/java/org/mage/test/serverside/CardIconsTest.java
index 37b7d33efa..dae5855e90 100644
--- a/Mage.Tests/src/test/java/org/mage/test/serverside/CardIconsTest.java
+++ b/Mage.Tests/src/test/java/org/mage/test/serverside/CardIconsTest.java
@@ -152,4 +152,73 @@ public class CardIconsTest extends CardTestPlayerBase {
         execute();
         assertAllCommandsUsed();
     }
+
+    @Test
+    public void test_CostX_Abilities() {
+        // X icon must be visible only for activated ability, not spell cast
+
+        // {X}{R}, {tap}, Sacrifice Cinder Elemental: Cinder Elemental deals X damage to any target.
+        addCard(Zone.HAND, playerA, "Cinder Elemental", 1); // {3}{R}
+        addCard(Zone.BATTLEFIELD, playerA, "Mountain", 4);
+
+        // hand (not visible)
+        runCode("card icons in hand", 1, PhaseStep.PRECOMBAT_MAIN, playerA, (info, player, game) -> {
+            GameView gameView = getGameView(player);
+            Assert.assertEquals("must have 1 card in hand", 1, gameView.getHand().values().size());
+            CardView cardView = gameView.getHand().values().stream().findFirst().get();
+            Assert.assertEquals("must have non x cost card icons in hand", 0, cardView.getCardIcons().size());
+        });
+
+        // spell cast
+        castSpell(1, PhaseStep.PRECOMBAT_MAIN, playerA, "Cinder Elemental");
+
+        // stack (spell cast - not visible)
+        runCode("card icons on stack (spell cast - not visible)", 1, PhaseStep.PRECOMBAT_MAIN, playerA, (info, player, game) -> {
+            GameView gameView = getGameView(player);
+            Assert.assertEquals("must have 1 card in stack", 1, gameView.getStack().values().size());
+            CardView cardView = gameView.getStack().values().stream().findFirst().get();
+            Assert.assertEquals("must have not x cost card icons in stack", 0, cardView.getCardIcons().size());
+        });
+
+        waitStackResolved(1, PhaseStep.PRECOMBAT_MAIN);
+        checkPermanentCount("after cast", 1, PhaseStep.PRECOMBAT_MAIN, playerA, "Cinder Elemental", 1);
+
+        // battlefield (card, not visible)
+        runCode("card icons in battlefield (card)", 1, PhaseStep.PRECOMBAT_MAIN, playerA, (info, player, game) -> {
+            GameView gameView = getGameView(player);
+            PlayerView playerView = gameView.getPlayers().get(0);
+            Assert.assertEquals("player", player.getName(), playerView.getName());
+            CardView cardView = playerView.getBattlefield().values().stream().filter(p -> p.getName().equals("Cinder Elemental")).findFirst().orElse(null);
+            Assert.assertNotNull("must have Cinder Elemental in battlefield", cardView);
+            Assert.assertEquals("must have not x cost card icons in battlefield (card)", 0, cardView.getCardIcons().size());
+        });
+
+        // ACTIVATE ABILITY (x must be visible in stack, but not visible after resolve)
+        activateAbility(3, PhaseStep.PRECOMBAT_MAIN, playerA, "{X}{R}");
+        setChoice(playerA, "X=2");
+        addTarget(playerA, playerB);
+
+        // stack (ability activated - visible)
+        runCode("card icons on stack (ability activated - visible)", 3, PhaseStep.PRECOMBAT_MAIN, playerA, (info, player, game) -> {
+            GameView gameView = getGameView(player);
+            Assert.assertEquals("ability activated - must have 1 card in stack", 1, gameView.getStack().values().size());
+            CardView cardView = gameView.getStack().values().stream().findFirst().get();
+            Assert.assertEquals("ability activated - must have x cost card icons in stack", 1, cardView.getCardIcons().size());
+        });
+
+        // battlefield (ability activated, not visible)
+        runCode("card icons in battlefield (ability activated)", 1, PhaseStep.PRECOMBAT_MAIN, playerA, (info, player, game) -> {
+            GameView gameView = getGameView(player);
+            PlayerView playerView = gameView.getPlayers().get(0);
+            Assert.assertEquals("player", player.getName(), playerView.getName());
+            CardView cardView = playerView.getBattlefield().values().stream().filter(p -> p.getName().equals("Cinder Elemental")).findFirst().orElse(null);
+            Assert.assertNotNull("ability activated - must have Cinder Elemental in battlefield", cardView);
+            Assert.assertEquals("ability activated - must have not x cost card icons in battlefield", 0, cardView.getCardIcons().size());
+        });
+
+        setStrictChooseMode(true);
+        setStopAt(3, PhaseStep.END_TURN);
+        execute();
+        assertAllCommandsUsed();
+    }
 }