diff --git a/Mage/src/main/java/mage/abilities/effects/common/ChooseACardNameEffect.java b/Mage/src/main/java/mage/abilities/effects/common/ChooseACardNameEffect.java
index e8fc6ab1086..86edae8d1f2 100644
--- a/Mage/src/main/java/mage/abilities/effects/common/ChooseACardNameEffect.java
+++ b/Mage/src/main/java/mage/abilities/effects/common/ChooseACardNameEffect.java
@@ -18,7 +18,7 @@ import mage.util.CardUtil;
  */
 public class ChooseACardNameEffect extends OneShotEffect {
 
-    public static String INFO_KEY = "NAMED_CARD";
+    public static final String INFO_KEY = "NAMED_CARD";
 
     public enum TypeOfName {
 
diff --git a/Mage/src/main/java/mage/abilities/effects/common/ChooseBasicLandTypeEffect.java b/Mage/src/main/java/mage/abilities/effects/common/ChooseBasicLandTypeEffect.java
index ee844548314..739aaaeca46 100644
--- a/Mage/src/main/java/mage/abilities/effects/common/ChooseBasicLandTypeEffect.java
+++ b/Mage/src/main/java/mage/abilities/effects/common/ChooseBasicLandTypeEffect.java
@@ -22,7 +22,7 @@ import mage.util.CardUtil;
  */
 public class ChooseBasicLandTypeEffect extends OneShotEffect {
 
-    public static String VALUE_KEY = "BasicLandType";
+    public static final String VALUE_KEY = "BasicLandType";
 
     public ChooseBasicLandTypeEffect(Outcome outcome) {
         super(outcome);
diff --git a/Mage/src/main/java/mage/abilities/effects/common/ChooseOpponentEffect.java b/Mage/src/main/java/mage/abilities/effects/common/ChooseOpponentEffect.java
index 8b7662df2bb..8c841e907f7 100644
--- a/Mage/src/main/java/mage/abilities/effects/common/ChooseOpponentEffect.java
+++ b/Mage/src/main/java/mage/abilities/effects/common/ChooseOpponentEffect.java
@@ -21,7 +21,7 @@ import mage.util.CardUtil;
  */
 public class ChooseOpponentEffect extends OneShotEffect {
 
-    public static String VALUE_KEY = "_opponent";
+    public static final String VALUE_KEY = "_opponent";
 
     public ChooseOpponentEffect(Outcome outcome) {
         super(outcome);
diff --git a/Mage/src/main/java/mage/abilities/effects/keyword/FatesealEffect.java b/Mage/src/main/java/mage/abilities/effects/keyword/FatesealEffect.java
index cf36084701c..264c11484ef 100644
--- a/Mage/src/main/java/mage/abilities/effects/keyword/FatesealEffect.java
+++ b/Mage/src/main/java/mage/abilities/effects/keyword/FatesealEffect.java
@@ -24,7 +24,7 @@ import mage.util.CardUtil;
 
 public class FatesealEffect extends OneShotEffect {
 
-    protected static FilterCard filter1 = new FilterCard("card to put on the bottom of opponent's library");
+    protected static final FilterCard filter1 = new FilterCard("card to put on the bottom of opponent's library");
 
     protected int fatesealNumber;
 
diff --git a/Mage/src/main/java/mage/abilities/keyword/AscendAbility.java b/Mage/src/main/java/mage/abilities/keyword/AscendAbility.java
index 3a0334470f4..2292030e096 100644
--- a/Mage/src/main/java/mage/abilities/keyword/AscendAbility.java
+++ b/Mage/src/main/java/mage/abilities/keyword/AscendAbility.java
@@ -22,7 +22,7 @@ import mage.players.Player;
  */
 public class AscendAbility extends SimpleStaticAbility {
 
-    public static String ASCEND_RULE = "Ascend <i>(If you control ten or more permanents, you get the city's blessing for the rest of the game.)</i>";
+    public static final String ASCEND_RULE = "Ascend <i>(If you control ten or more permanents, you get the city's blessing for the rest of the game.)</i>";
 
     public AscendAbility() {
         super(Zone.BATTLEFIELD, new AscendContinuousEffect());
diff --git a/Mage/src/main/java/mage/cards/decks/Constructed.java b/Mage/src/main/java/mage/cards/decks/Constructed.java
index ba744471853..23410c32b5d 100644
--- a/Mage/src/main/java/mage/cards/decks/Constructed.java
+++ b/Mage/src/main/java/mage/cards/decks/Constructed.java
@@ -17,8 +17,8 @@ public class Constructed extends DeckValidator {
 
     private static final Logger logger = Logger.getLogger(DeckValidator.class);
 
-    protected static List<String> anyNumberCardsAllowed = new ArrayList<>(Arrays.asList("Relentless Rats", "Shadowborn Apostle", "Rat Colony"));
-    protected static List<String> basicLandNames = new ArrayList<>(
+    protected static final List<String> anyNumberCardsAllowed = new ArrayList<>(Arrays.asList("Relentless Rats", "Shadowborn Apostle", "Rat Colony"));
+    protected static final List<String> basicLandNames = new ArrayList<>(
             Arrays.asList("Forest", "Island", "Mountain", "Swamp", "Plains", "Wastes", "Snow-Covered Forest",
                     "Snow-Covered Island", "Snow-Covered Mountain", "Snow-Covered Swamp", "Snow-Covered Plains"));
     protected List<String> banned = new ArrayList<>();
diff --git a/Mage/src/main/java/mage/cards/decks/importer/DeckImporterUtil.java b/Mage/src/main/java/mage/cards/decks/importer/DeckImporterUtil.java
index 2912dafd7e7..a0e90dc5261 100644
--- a/Mage/src/main/java/mage/cards/decks/importer/DeckImporterUtil.java
+++ b/Mage/src/main/java/mage/cards/decks/importer/DeckImporterUtil.java
@@ -12,7 +12,7 @@ import mage.cards.decks.DeckCardLists;
  */
 public final class DeckImporterUtil {
 
-    public static final String[] SIDEBOARD_MARKS = new String[]{"//sideboard", "sb: "};
+    private static final String[] SIDEBOARD_MARKS = new String[]{"//sideboard", "sb: "};
 
     public static boolean haveSideboardSection(String file) {
         // search for sideboard section:
diff --git a/Mage/src/main/java/mage/cards/decks/importer/TxtDeckImporter.java b/Mage/src/main/java/mage/cards/decks/importer/TxtDeckImporter.java
index 14d2b31f570..4d593610ff5 100644
--- a/Mage/src/main/java/mage/cards/decks/importer/TxtDeckImporter.java
+++ b/Mage/src/main/java/mage/cards/decks/importer/TxtDeckImporter.java
@@ -16,9 +16,9 @@ import mage.cards.repository.CardRepository;
  */
 public class TxtDeckImporter extends DeckImporter {
 
-    public static final String[] SET_VALUES = new String[]{"lands", "creatures", "planeswalkers", "other spells", "sideboard cards",
+    private static final String[] SET_VALUES = new String[]{"lands", "creatures", "planeswalkers", "other spells", "sideboard cards",
         "Instant", "Land", "Enchantment", "Artifact", "Sorcery", "Planeswalker", "Creature"};
-    public static final Set<String> IGNORE_NAMES = new HashSet<>(Arrays.asList(SET_VALUES));
+    private static final Set<String> IGNORE_NAMES = new HashSet<>(Arrays.asList(SET_VALUES));
 
     private boolean sideboard = false;
     private boolean switchSideboardByEmptyLine = true; // all cards after first empty line will be sideboard (like mtgo format)