diff --git a/Mage.Client/src/main/java/mage/client/table/TablesPanel.java b/Mage.Client/src/main/java/mage/client/table/TablesPanel.java
index 56dacd4e4c..59cdb09259 100644
--- a/Mage.Client/src/main/java/mage/client/table/TablesPanel.java
+++ b/Mage.Client/src/main/java/mage/client/table/TablesPanel.java
@@ -636,7 +636,7 @@ public class TablesPanel extends javax.swing.JPanel {
         List<RowFilter<Object, Object>> ignoreListFilterList = new ArrayList<>();
         String serverAddress = SessionHandler.getSession().getServerHostname().orElseGet(() -> "");
         final Set<String> ignoreListCopy = IgnoreList.ignoreList(serverAddress);
-        if (ignoreListCopy.size() > 0) {
+        if (!ignoreListCopy.isEmpty()) {
             ignoreListFilterList.add(new RowFilter<Object, Object>() {
                 @Override
                 public boolean include(Entry<? extends Object, ? extends Object> entry) {
diff --git a/Mage.Client/src/main/java/mage/client/util/IgnoreList.java b/Mage.Client/src/main/java/mage/client/util/IgnoreList.java
index 8b0125dfd5..0fc95791b6 100644
--- a/Mage.Client/src/main/java/mage/client/util/IgnoreList.java
+++ b/Mage.Client/src/main/java/mage/client/util/IgnoreList.java
@@ -36,7 +36,7 @@ public final class IgnoreList {
     }
 
     public static String ignore(String serverAddress, String user) {
-        if (user == null || user.length() == 0) {
+        if (user == null || user.isEmpty()) {
             return ignoreListString(serverAddress);
         }
 
@@ -71,7 +71,7 @@ public final class IgnoreList {
     }
 
     public static String unignore(String serverAddress, String user) {
-        if (user == null || user.length() == 0) {
+        if (user == null || user.isEmpty()) {
             return usage();
         }
         if (MagePreferences.removeIgnoredUser(serverAddress, user)) {
diff --git a/Mage.Client/src/main/java/mage/client/util/gui/ArrowBuilder.java b/Mage.Client/src/main/java/mage/client/util/gui/ArrowBuilder.java
index 4a2b66979e..df4650ea3b 100644
--- a/Mage.Client/src/main/java/mage/client/util/gui/ArrowBuilder.java
+++ b/Mage.Client/src/main/java/mage/client/util/gui/ArrowBuilder.java
@@ -143,7 +143,7 @@ public class ArrowBuilder {
         if (map.containsKey(gameId)) {
             Map<Type, List<Arrow>> innerMap = map.get(gameId);
             java.util.List<Arrow> arrows = innerMap.get(type);
-            if (arrows != null && arrows.size() > 0) {
+            if (arrows != null && !arrows.isEmpty()) {
                 JPanel p = getArrowsPanel(gameId);
                 synchronized (map) {
                     for (Arrow arrow : arrows) {
diff --git a/Mage.Server.Plugins/Mage.Deck.Constructed/src/mage/deck/CanadianHighlander.java b/Mage.Server.Plugins/Mage.Deck.Constructed/src/mage/deck/CanadianHighlander.java
index 00ac1782ec..64372f5636 100644
--- a/Mage.Server.Plugins/Mage.Deck.Constructed/src/mage/deck/CanadianHighlander.java
+++ b/Mage.Server.Plugins/Mage.Deck.Constructed/src/mage/deck/CanadianHighlander.java
@@ -67,7 +67,7 @@ public class CanadianHighlander extends Constructed {
             valid = false;
         }
 
-        if (deck.getSideboard().size() > 0) {
+        if (!deck.getSideboard().isEmpty()) {
             invalid.put("Deck", "Sideboard can't contain any cards: has " + (deck.getSideboard().size()) + " cards");
             valid = false;
         }