diff --git a/src/main/java/net/knarcraft/minigames/arena/ArenaHandler.java b/src/main/java/net/knarcraft/minigames/arena/ArenaHandler.java
index f55338b..5b539ca 100644
--- a/src/main/java/net/knarcraft/minigames/arena/ArenaHandler.java
+++ b/src/main/java/net/knarcraft/minigames/arena/ArenaHandler.java
@@ -15,22 +15,22 @@ import java.util.logging.Level;
 /**
  * An interface describing a generic arena handler
  *
- * @param <K> <p>The type of arena stored</p>
- * @param <S> <p>The type of arena group stored</p>
+ * @param <ArenaType> <p>The type of arena stored</p>
+ * @param <GroupType> <p>The type of arena group stored</p>
  */
-public abstract class ArenaHandler<K extends Arena, S extends ArenaGroup<K, S>> {
+public abstract class ArenaHandler<ArenaType extends Arena, GroupType extends ArenaGroup<ArenaType, GroupType>> {
 
-    protected Map<UUID, K> arenas = new HashMap<>();
-    protected Map<UUID, S> arenaGroups = new HashMap<>();
+    protected Map<UUID, ArenaType> arenas = new HashMap<>();
+    protected Map<UUID, GroupType> arenaGroups = new HashMap<>();
     protected Map<String, UUID> arenaNameLookup = new HashMap<>();
-    private final ArenaPlayerRegistry<K> playerRegistry;
+    private final ArenaPlayerRegistry<ArenaType> playerRegistry;
 
     /**
      * Instantiates a new arena handler
      *
      * @param playerRegistry <p>The registry keeping track of player sessions</p>
      */
-    public ArenaHandler(ArenaPlayerRegistry<K> playerRegistry) {
+    public ArenaHandler(@NotNull ArenaPlayerRegistry<ArenaType> playerRegistry) {
         this.playerRegistry = playerRegistry;
     }
 
@@ -39,8 +39,8 @@ public abstract class ArenaHandler<K extends Arena, S extends ArenaGroup<K, S>>
      *
      * @return <p>All arenas in a group</p>
      */
-    public @NotNull Set<K> getArenasInAGroup() {
-        Set<K> arenas = new HashSet<>();
+    public @NotNull Set<ArenaType> getArenasInAGroup() {
+        Set<ArenaType> arenas = new HashSet<>();
         for (UUID arenaId : arenaGroups.keySet()) {
             arenas.add(this.arenas.get(arenaId));
         }
@@ -52,7 +52,7 @@ public abstract class ArenaHandler<K extends Arena, S extends ArenaGroup<K, S>>
      *
      * @return <p>All arena groups</p>
      */
-    public Set<S> getAllGroups() {
+    public Set<GroupType> getAllGroups() {
         return new HashSet<>(arenaGroups.values());
     }
 
@@ -62,7 +62,7 @@ public abstract class ArenaHandler<K extends Arena, S extends ArenaGroup<K, S>>
      * @param arenaId <p>The id of the arena to get the group of</p>
      * @return <p>The group the arena belongs to, or null if not in a group</p>
      */
-    public @Nullable S getGroup(@NotNull UUID arenaId) {
+    public @Nullable GroupType getGroup(@NotNull UUID arenaId) {
         return this.arenaGroups.get(arenaId);
     }
 
@@ -72,7 +72,7 @@ public abstract class ArenaHandler<K extends Arena, S extends ArenaGroup<K, S>>
      * @param arenaId    <p>The id of the arena to change</p>
      * @param arenaGroup <p>The group to add the arena to, or null to remove the current group</p>
      */
-    public void setGroup(@NotNull UUID arenaId, @Nullable S arenaGroup) {
+    public void setGroup(@NotNull UUID arenaId, @Nullable GroupType arenaGroup) {
         if (arenaGroup == null) {
             // No need to remove something non-existing
             if (!this.arenaGroups.containsKey(arenaId)) {
@@ -80,7 +80,7 @@ public abstract class ArenaHandler<K extends Arena, S extends ArenaGroup<K, S>>
             }
 
             // Remove the existing group
-            S oldGroup = this.arenaGroups.remove(arenaId);
+            GroupType oldGroup = this.arenaGroups.remove(arenaId);
             oldGroup.removeArena(arenaId);
         } else {
             // Make sure to remove the arena from the old group's internal tracking
@@ -100,9 +100,9 @@ public abstract class ArenaHandler<K extends Arena, S extends ArenaGroup<K, S>>
      * @param groupName <p>The name of the group to get</p>
      * @return <p>The group, or null if not found</p>
      */
-    public @Nullable S getGroup(String groupName) {
+    public @Nullable GroupType getGroup(@NotNull String groupName) {
         String sanitized = StringSanitizer.sanitizeArenaName(groupName);
-        for (S arenaGroup : this.arenaGroups.values()) {
+        for (GroupType arenaGroup : this.arenaGroups.values()) {
             if (arenaGroup.getGroupNameSanitized().equals(sanitized)) {
                 return arenaGroup;
             }
@@ -128,7 +128,7 @@ public abstract class ArenaHandler<K extends Arena, S extends ArenaGroup<K, S>>
      *
      * @param arena <p>The arena to add</p>
      */
-    public void addArena(@NotNull K arena) {
+    public void addArena(@NotNull ArenaType arena) {
         this.arenas.put(arena.getArenaId(), arena);
         this.arenaNameLookup.put(arena.getArenaNameSanitized(), arena.getArenaId());
         this.saveArenas();
@@ -140,7 +140,7 @@ public abstract class ArenaHandler<K extends Arena, S extends ArenaGroup<K, S>>
      * @param arenaId <p>The id of the arena to get</p>
      * @return <p>The arena, or null if no arena could be found</p>
      */
-    public @Nullable K getArena(@NotNull UUID arenaId) {
+    public @Nullable ArenaType getArena(@NotNull UUID arenaId) {
         return this.arenas.get(arenaId);
     }
 
@@ -150,7 +150,7 @@ public abstract class ArenaHandler<K extends Arena, S extends ArenaGroup<K, S>>
      * @param arenaName <p>The arena to get</p>
      * @return <p>The arena with the given name, or null if not found</p>
      */
-    public @Nullable K getArena(@NotNull String arenaName) {
+    public @Nullable ArenaType getArena(@NotNull String arenaName) {
         try {
             return this.arenas.get(UUID.fromString(arenaName));
         } catch (IllegalArgumentException exception) {
@@ -163,7 +163,7 @@ public abstract class ArenaHandler<K extends Arena, S extends ArenaGroup<K, S>>
      *
      * @return <p>All known arenas</p>
      */
-    public @NotNull Map<UUID, K> getArenas() {
+    public @NotNull Map<UUID, ArenaType> getArenas() {
         return new HashMap<>(this.arenas);
     }
 
@@ -172,7 +172,7 @@ public abstract class ArenaHandler<K extends Arena, S extends ArenaGroup<K, S>>
      *
      * @param arena <p>The arena to remove</p>
      */
-    public void removeArena(@NotNull K arena) {
+    public void removeArena(@NotNull ArenaType arena) {
         UUID arenaId = arena.getArenaId();
         this.playerRegistry.removeForArena(arena, false);
         this.arenas.remove(arenaId);
@@ -190,8 +190,8 @@ public abstract class ArenaHandler<K extends Arena, S extends ArenaGroup<K, S>>
      *
      * @param arenaId <p>The id of the arena whose data should be saved</p>
      */
-    public void saveData(UUID arenaId) {
-        K arena = getArena(arenaId);
+    public void saveData(@NotNull UUID arenaId) {
+        ArenaType arena = getArena(arenaId);
         if (arena != null) {
             if (!arena.saveData()) {
                 MiniGames.log(Level.WARNING, "Unable to save data for arena with id " + arenaId +
diff --git a/src/main/java/net/knarcraft/minigames/arena/ArenaRecordsRegistry.java b/src/main/java/net/knarcraft/minigames/arena/ArenaRecordsRegistry.java
index e1ed506..bd2c6e0 100644
--- a/src/main/java/net/knarcraft/minigames/arena/ArenaRecordsRegistry.java
+++ b/src/main/java/net/knarcraft/minigames/arena/ArenaRecordsRegistry.java
@@ -54,6 +54,7 @@ public abstract class ArenaRecordsRegistry implements ConfigurationSerializable
      *
      * @return <p>Existing death records</p>
      */
+    @NotNull
     public Set<SummableArenaRecord<Integer>> getLeastDeathsRecords() {
         return new HashSet<>(this.leastDeaths);
     }
@@ -63,6 +64,7 @@ public abstract class ArenaRecordsRegistry implements ConfigurationSerializable
      *
      * @return <p>Existing time records</p>
      */
+    @NotNull
     public Set<SummableArenaRecord<Long>> getShortestTimeMilliSecondsRecords() {
         return new HashSet<>(this.shortestTimeMilliSeconds);
     }
@@ -74,7 +76,8 @@ public abstract class ArenaRecordsRegistry implements ConfigurationSerializable
      * @param deaths   <p>The number of deaths suffered before the player finished the arena</p>
      * @return <p>The result explaining what type of record was achieved</p>
      */
-    public @NotNull RecordResult registerDeathRecord(@NotNull UUID playerId, int deaths) {
+    @NotNull
+    public RecordResult registerDeathRecord(@NotNull UUID playerId, int deaths) {
         Consumer<Integer> consumer = (value) -> {
             leastDeaths.removeIf((item) -> item.getUserId().equals(playerId));
             leastDeaths.add(new IntegerRecord(playerId, value));
@@ -89,7 +92,8 @@ public abstract class ArenaRecordsRegistry implements ConfigurationSerializable
      * @param milliseconds <p>The number of milliseconds it took the player to finish the dropper arena</p>
      * @return <p>The result explaining what type of record was achieved</p>
      */
-    public @NotNull RecordResult registerTimeRecord(@NotNull UUID playerId, long milliseconds) {
+    @NotNull
+    public RecordResult registerTimeRecord(@NotNull UUID playerId, long milliseconds) {
         Consumer<Long> consumer = (value) -> {
             shortestTimeMilliSeconds.removeIf((item) -> item.getUserId().equals(playerId));
             shortestTimeMilliSeconds.add(new LongRecord(playerId, value));
@@ -111,9 +115,10 @@ public abstract class ArenaRecordsRegistry implements ConfigurationSerializable
      * @param amount          <p>The amount of whatever the player achieved</p>
      * @return <p>The result of the player's record attempt</p>
      */
-    private <T extends Comparable<T>> @NotNull RecordResult registerRecord(@NotNull Set<ArenaRecord<T>> existingRecords,
-                                                                           @NotNull Consumer<T> recordSetter,
-                                                                           @NotNull UUID playerId, T amount) {
+    @NotNull
+    private <RecordType extends Comparable<RecordType>> RecordResult registerRecord(@NotNull Set<ArenaRecord<RecordType>> existingRecords,
+                                                                                    @NotNull Consumer<RecordType> recordSetter,
+                                                                                    @NotNull UUID playerId, RecordType amount) {
         RecordResult result;
         if (existingRecords.stream().allMatch((entry) -> amount.compareTo(entry.getRecord()) < 0)) {
             // If the given value is less than all other values, that's a world record!
@@ -123,7 +128,7 @@ public abstract class ArenaRecordsRegistry implements ConfigurationSerializable
             return result;
         }
 
-        ArenaRecord<T> playerRecord = getRecord(existingRecords, playerId);
+        ArenaRecord<RecordType> playerRecord = getRecord(existingRecords, playerId);
         if (playerRecord != null && amount.compareTo(playerRecord.getRecord()) < 0) {
             // If the given value is less than the player's previous value, that's a personal best!
             result = RecordResult.PERSONAL_BEST;
@@ -146,12 +151,13 @@ public abstract class ArenaRecordsRegistry implements ConfigurationSerializable
      *
      * @param existingRecords <p>The existing records to look through</p>
      * @param playerId        <p>The id of the player to look for</p>
-     * @param <T>             <p>The type of the stored record</p>
+     * @param <RecordType>    <p>The type of the stored record</p>
      * @return <p>The record, or null if not found</p>
      */
-    private <T extends Comparable<T>> @Nullable ArenaRecord<T> getRecord(@NotNull Set<ArenaRecord<T>> existingRecords,
-                                                                         @NotNull UUID playerId) {
-        AtomicReference<ArenaRecord<T>> record = new AtomicReference<>();
+    @Nullable
+    private <RecordType extends Comparable<RecordType>> ArenaRecord<RecordType> getRecord(@NotNull Set<ArenaRecord<RecordType>> existingRecords,
+                                                                                          @NotNull UUID playerId) {
+        AtomicReference<ArenaRecord<RecordType>> record = new AtomicReference<>();
         existingRecords.forEach((item) -> {
             if (item.getUserId().equals(playerId)) {
                 record.set(item);
diff --git a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArena.java b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArena.java
index cdb250f..d095c1a 100644
--- a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArena.java
+++ b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArena.java
@@ -35,23 +35,27 @@ public class DropperArena implements Arena {
     /**
      * An unique and persistent identifier for this arena
      */
+    @NotNull
     private final UUID arenaId;
 
     /**
      * A name used when listing and storing this arena.
      */
-    private @NotNull String arenaName;
+    @NotNull
+    private String arenaName;
 
     /**
      * The location players are teleported to when joining this arena.
      */
-    private @NotNull Location spawnLocation;
+    @NotNull
+    private Location spawnLocation;
 
     /**
      * The location players will be sent to when they win or lose the arena. If not set, their entry location should be
      * used instead.
      */
-    private @Nullable Location exitLocation;
+    @Nullable
+    private Location exitLocation;
 
     /**
      * The velocity in the y-direction to apply to all players in this arena.
@@ -73,27 +77,34 @@ public class DropperArena implements Arena {
     /**
      * Types of damage that won't be blocked in this arena
      */
+    @NotNull
     private Set<EntityDamageEvent.DamageCause> allowedDamageCauses;
 
     /**
      * Types of damage that will trigger a loss in this arena
      */
+    @NotNull
     private Set<EntityDamageEvent.DamageCause> lossTriggerDamageCauses;
 
     /**
      * The material of the block players have to hit to win this dropper arena
      */
-    private @NotNull Material winBlockType;
+    @NotNull
+    private Material winBlockType;
 
     /**
      * The arena data for this arena
      */
+    @NotNull
     private final DropperArenaData dropperArenaData;
 
+    @NotNull
     private final DropperArenaHandler dropperArenaHandler;
 
+    @NotNull
     private Map<RewardCondition, Set<Reward>> rewards = new HashMap<>();
 
+    @NotNull
     private static final DropperConfiguration dropperConfiguration = MiniGames.getInstance().getDropperConfiguration();
 
     /**
@@ -168,27 +179,32 @@ public class DropperArena implements Arena {
     }
 
     @Override
-    public @NotNull DropperArenaData getData() {
+    @NotNull
+    public DropperArenaData getData() {
         return this.dropperArenaData;
     }
 
     @Override
-    public @NotNull UUID getArenaId() {
+    @NotNull
+    public UUID getArenaId() {
         return this.arenaId;
     }
 
     @Override
-    public @NotNull String getArenaName() {
+    @NotNull
+    public String getArenaName() {
         return this.arenaName;
     }
 
     @Override
-    public @NotNull Location getSpawnLocation() {
+    @NotNull
+    public Location getSpawnLocation() {
         return this.spawnLocation.clone();
     }
 
     @Override
-    public @Nullable Location getExitLocation() {
+    @Nullable
+    public Location getExitLocation() {
         return this.exitLocation != null ? this.exitLocation.clone() : null;
     }
 
@@ -206,7 +222,8 @@ public class DropperArena implements Arena {
     }
 
     @Override
-    public @NotNull Set<Reward> getRewards(RewardCondition rewardCondition) {
+    @NotNull
+    public Set<Reward> getRewards(@NotNull RewardCondition rewardCondition) {
         if (this.rewards.containsKey(rewardCondition) && this.rewards.get(rewardCondition) != null) {
             return this.rewards.get(rewardCondition);
         } else {
@@ -231,12 +248,14 @@ public class DropperArena implements Arena {
     }
 
     @Override
-    public @NotNull Set<EntityDamageEvent.DamageCause> getAllowedDamageCauses() {
+    @NotNull
+    public Set<EntityDamageEvent.DamageCause> getAllowedDamageCauses() {
         return this.allowedDamageCauses;
     }
 
     @Override
-    public @NotNull Set<EntityDamageEvent.DamageCause> getLossTriggerDamageCauses() {
+    @NotNull
+    public Set<EntityDamageEvent.DamageCause> getLossTriggerDamageCauses() {
         return this.lossTriggerDamageCauses;
     }
 
@@ -414,11 +433,8 @@ public class DropperArena implements Arena {
     }
 
     @Override
-    public boolean equals(Object other) {
-        if (!(other instanceof DropperArena otherArena)) {
-            return false;
-        }
-        return this.getArenaNameSanitized().equals(otherArena.getArenaNameSanitized());
+    public boolean equals(@Nullable Object other) {
+        return other instanceof DropperArena otherArena && this.getArenaNameSanitized().equals(otherArena.getArenaNameSanitized());
     }
 
 }
diff --git a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaData.java b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaData.java
index c6aa6cb..3051e95 100644
--- a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaData.java
+++ b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaData.java
@@ -44,7 +44,8 @@ public class DropperArenaData extends ArenaData {
      * @return <p>The deserialized dropper arena data</p>
      */
     @SuppressWarnings({"unused", "unchecked"})
-    public static @NotNull DropperArenaData deserialize(@NotNull Map<String, Object> data) {
+    @NotNull
+    public static DropperArenaData deserialize(@NotNull Map<String, Object> data) {
         SerializableUUID serializableUUID = (SerializableUUID) data.get("arenaId");
         Map<ArenaGameMode, ArenaRecordsRegistry> recordsRegistry =
                 (Map<ArenaGameMode, ArenaRecordsRegistry>) data.get("recordsRegistry");
diff --git a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaEditableProperty.java b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaEditableProperty.java
index 7dee509..65ff9c0 100644
--- a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaEditableProperty.java
+++ b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaEditableProperty.java
@@ -77,8 +77,9 @@ public enum DropperArenaEditableProperty {
      *
      * @param argumentString <p>The argument string used to specify this property</p>
      */
-    DropperArenaEditableProperty(@NotNull String argumentString, Function<DropperArena, String> currentValueProvider,
-                                 EditablePropertyType propertyType) {
+    DropperArenaEditableProperty(@NotNull String argumentString,
+                                 @NotNull Function<DropperArena, String> currentValueProvider,
+                                 @NotNull EditablePropertyType propertyType) {
         this.argumentString = argumentString;
         this.currentValueProvider = currentValueProvider;
         this.propertyType = propertyType;
@@ -89,6 +90,7 @@ public enum DropperArenaEditableProperty {
      *
      * @return <p>The type of this property</p>
      */
+    @NotNull
     public EditablePropertyType getPropertyType() {
         return this.propertyType;
     }
@@ -99,7 +101,8 @@ public enum DropperArenaEditableProperty {
      * @param arena <p>The arena to check the value for</p>
      * @return <p>The current value as a string</p>
      */
-    public String getCurrentValueAsString(DropperArena arena) {
+    @NotNull
+    public String getCurrentValueAsString(@NotNull DropperArena arena) {
         return this.currentValueProvider.apply(arena);
     }
 
@@ -108,7 +111,8 @@ public enum DropperArenaEditableProperty {
      *
      * @return <p>The argument string</p>
      */
-    public @NotNull String getArgumentString() {
+    @NotNull
+    public String getArgumentString() {
         return this.argumentString;
     }
 
@@ -118,7 +122,8 @@ public enum DropperArenaEditableProperty {
      * @param argumentString <p>The argument string used to specify an editable property</p>
      * @return <p>The corresponding editable property, or null if not found</p>
      */
-    public static @Nullable DropperArenaEditableProperty getFromArgumentString(String argumentString) {
+    @Nullable
+    public static DropperArenaEditableProperty getFromArgumentString(@NotNull String argumentString) {
         for (DropperArenaEditableProperty property : DropperArenaEditableProperty.values()) {
             if (property.argumentString.equalsIgnoreCase(argumentString)) {
                 return property;
diff --git a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaGameMode.java b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaGameMode.java
index 1a60463..cdef49e 100644
--- a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaGameMode.java
+++ b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaGameMode.java
@@ -34,7 +34,8 @@ public enum DropperArenaGameMode implements ConfigurationSerializable, ArenaGame
      * @param gameMode <p>The game-mode string to match</p>
      * @return <p>The specified arena game-mode</p>
      */
-    public static @NotNull DropperArenaGameMode matchGameMode(@NotNull String gameMode) {
+    @NotNull
+    public static DropperArenaGameMode matchGameMode(@NotNull String gameMode) {
         String sanitized = gameMode.trim().toLowerCase();
         if (sanitized.matches("(invert(ed)?|inverse)")) {
             return DropperArenaGameMode.INVERTED;
@@ -60,12 +61,14 @@ public enum DropperArenaGameMode implements ConfigurationSerializable, ArenaGame
      * @return <p>The deserialized arena game-mode</p>
      */
     @SuppressWarnings("unused")
-    public static DropperArenaGameMode deserialize(Map<String, Object> data) {
+    @NotNull
+    public static DropperArenaGameMode deserialize(@NotNull Map<String, Object> data) {
         return DropperArenaGameMode.valueOf((String) data.get("name"));
     }
 
     @Override
-    public @NotNull DropperArenaGameMode[] getValues() {
+    @NotNull
+    public DropperArenaGameMode[] getValues() {
         return DropperArenaGameMode.values();
     }
 
diff --git a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaGroup.java b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaGroup.java
index 4ed2236..817b03d 100644
--- a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaGroup.java
+++ b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaGroup.java
@@ -43,7 +43,8 @@ public class DropperArenaGroup extends ArenaGroup<DropperArena, DropperArenaGrou
      * @return <p>The deserialized arena group</p>
      */
     @SuppressWarnings({"unused", "unchecked"})
-    public static @NotNull DropperArenaGroup deserialize(@NotNull Map<String, Object> data) {
+    @NotNull
+    public static DropperArenaGroup deserialize(@NotNull Map<String, Object> data) {
         UUID id = ((SerializableUUID) data.get("groupId")).getRawValue();
         String name = (String) data.get("groupName");
         List<SerializableUUID> serializableArenas = (List<SerializableUUID>) data.get("arenas");
diff --git a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaHandler.java b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaHandler.java
index 1bb3f5b..9e98984 100644
--- a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaHandler.java
+++ b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaHandler.java
@@ -5,6 +5,7 @@ import net.knarcraft.minigames.arena.ArenaHandler;
 import net.knarcraft.minigames.arena.ArenaPlayerRegistry;
 import net.knarcraft.minigames.config.MiniGameMessage;
 import net.knarcraft.minigames.util.DropperArenaStorageHelper;
+import org.jetbrains.annotations.NotNull;
 
 import java.io.IOException;
 import java.util.HashMap;
@@ -24,7 +25,7 @@ public class DropperArenaHandler extends ArenaHandler<DropperArena, DropperArena
      *
      * @param playerRegistry <p>The registry keeping track of player sessions</p>
      */
-    public DropperArenaHandler(ArenaPlayerRegistry<DropperArena> playerRegistry) {
+    public DropperArenaHandler(@NotNull ArenaPlayerRegistry<DropperArena> playerRegistry) {
         super(playerRegistry);
     }
 
diff --git a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaPlayerRegistry.java b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaPlayerRegistry.java
index 8e82940..0ed7660 100644
--- a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaPlayerRegistry.java
+++ b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaPlayerRegistry.java
@@ -1,6 +1,7 @@
 package net.knarcraft.minigames.arena.dropper;
 
 import net.knarcraft.minigames.arena.AbstractArenaPlayerRegistry;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * A registry to keep track of which players are playing in which arenas
@@ -8,6 +9,7 @@ import net.knarcraft.minigames.arena.AbstractArenaPlayerRegistry;
 public class DropperArenaPlayerRegistry extends AbstractArenaPlayerRegistry<DropperArena> {
 
     @Override
+    @NotNull
     protected String getEntryStateStorageKey() {
         return "dropper";
     }
diff --git a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaRecordsRegistry.java b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaRecordsRegistry.java
index b23266b..8324afd 100644
--- a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaRecordsRegistry.java
+++ b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaRecordsRegistry.java
@@ -50,7 +50,8 @@ public class DropperArenaRecordsRegistry extends ArenaRecordsRegistry {
      * @return <p>The deserialized records registry</p>
      */
     @SuppressWarnings({"unused", "unchecked"})
-    public static DropperArenaRecordsRegistry deserialize(Map<String, Object> data) {
+    @NotNull
+    public static DropperArenaRecordsRegistry deserialize(@NotNull Map<String, Object> data) {
         UUID arenaId = ((SerializableUUID) data.get("arenaId")).getRawValue();
         Set<IntegerRecord> leastDeaths =
                 (Set<IntegerRecord>) data.getOrDefault("leastDeaths", new HashMap<>());
diff --git a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaSession.java b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaSession.java
index 0bc0588..0e38901 100644
--- a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaSession.java
+++ b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaSession.java
@@ -23,9 +23,12 @@ import java.util.logging.Level;
  */
 public class DropperArenaSession extends AbstractArenaSession {
 
-    private final @NotNull DropperArena arena;
-    private final @NotNull Player player;
-    private final @NotNull DropperArenaGameMode gameMode;
+    @NotNull
+    private final DropperArena arena;
+    @NotNull
+    private final Player player;
+    @NotNull
+    private final DropperArenaGameMode gameMode;
     private boolean startedMoving = false;
 
     /**
@@ -67,7 +70,8 @@ public class DropperArenaSession extends AbstractArenaSession {
      *
      * @return <p>This session's player</p>
      */
-    public @NotNull Player getPlayer() {
+    @NotNull
+    public Player getPlayer() {
         return this.player;
     }
 
@@ -76,12 +80,14 @@ public class DropperArenaSession extends AbstractArenaSession {
      *
      * @return <p>The game-mode for this session</p>
      */
-    public @NotNull DropperArenaGameMode getGameMode() {
+    @NotNull
+    public DropperArenaGameMode getGameMode() {
         return this.gameMode;
     }
 
     @Override
-    public @NotNull PlayerEntryState getEntryState() {
+    @NotNull
+    public PlayerEntryState getEntryState() {
         return this.entryState;
     }
 
@@ -120,12 +126,14 @@ public class DropperArenaSession extends AbstractArenaSession {
     }
 
     @Override
-    public @NotNull DropperArena getArena() {
+    @NotNull
+    public DropperArena getArena() {
         return this.arena;
     }
 
     @Override
-    public @NotNull ArenaGUI getGUI() {
+    @NotNull
+    public ArenaGUI getGUI() {
         if (GeyserHelper.isGeyserPlayer(this.player)) {
             return new DropperGUIBedrock(this.player);
         } else {
@@ -151,6 +159,7 @@ public class DropperArenaSession extends AbstractArenaSession {
     }
 
     @Override
+    @NotNull
     protected String getGameModeString() {
         return switch (this.gameMode) {
             case DEFAULT -> "default";
diff --git a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaStorageKey.java b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaStorageKey.java
index 033edd7..d8065e8 100644
--- a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaStorageKey.java
+++ b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperArenaStorageKey.java
@@ -69,7 +69,8 @@ public enum DropperArenaStorageKey implements StorageKey {
     LOSS_TRIGGER_DAMAGE_CAUSES("lossTriggerDamageCauses"),
     ;
 
-    private final @NotNull String key;
+    @NotNull
+    private final String key;
 
     /**
      * Instantiates a new arena storage key
@@ -81,7 +82,8 @@ public enum DropperArenaStorageKey implements StorageKey {
     }
 
     @Override
-    public @NotNull String getKey() {
+    @NotNull
+    public String getKey() {
         return this.key;
     }
 
diff --git a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperPlayerEntryState.java b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperPlayerEntryState.java
index e02e0c7..ee4284f 100644
--- a/src/main/java/net/knarcraft/minigames/arena/dropper/DropperPlayerEntryState.java
+++ b/src/main/java/net/knarcraft/minigames/arena/dropper/DropperPlayerEntryState.java
@@ -20,6 +20,7 @@ public class DropperPlayerEntryState extends AbstractPlayerEntryState {
 
     private final float originalFlySpeed;
     private final float horizontalVelocity;
+    @NotNull
     private final DropperArenaGameMode arenaGameMode;
 
     /**
@@ -118,7 +119,8 @@ public class DropperPlayerEntryState extends AbstractPlayerEntryState {
      * @return <p>The data to deserialize</p>
      */
     @SuppressWarnings({"unused", "unchecked"})
-    public static DropperPlayerEntryState deserialize(Map<String, Object> data) {
+    @NotNull
+    public static DropperPlayerEntryState deserialize(@NotNull Map<String, Object> data) {
         UUID playerId = ((SerializableUUID) data.get("playerId")).getRawValue();
         Location entryLocation = (Location) data.get("entryLocation");
         boolean originalIsFlying = getBoolean(data, "originalIsFlying");
diff --git a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArena.java b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArena.java
index a7bab58..ea5e776 100644
--- a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArena.java
+++ b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArena.java
@@ -38,53 +38,63 @@ public class ParkourArena implements Arena {
     /**
      * An unique and persistent identifier for this arena
      */
-    private final @NotNull UUID arenaId;
+    @NotNull
+    private final UUID arenaId;
 
     /**
      * A name used when listing and storing this arena.
      */
-    private @NotNull String arenaName;
+    @NotNull
+    private String arenaName;
 
     /**
      * The location players are teleported to when joining this arena.
      */
-    private @NotNull Location spawnLocation;
+    @NotNull
+    private Location spawnLocation;
 
     /**
      * The location players will be sent to when they win or lose the arena. If not set, their entry location should be
      * used instead.
      */
-    private @Nullable Location exitLocation;
+    @Nullable
+    private Location exitLocation;
 
     /**
      * The material of the block players have to hit to win this parkour arena
      */
-    private @NotNull Material winBlockType;
+    @NotNull
+    private Material winBlockType;
 
     /**
      * The location the player has to reach to win. If not set, winBlockType is used instead
      */
-    private @Nullable Location winLocation;
+    @Nullable
+    private Location winLocation;
 
     /**
      * The names of the block types constituting this arena's kill plane
      */
-    private @Nullable Set<String> killPlaneBlockNames;
+    @Nullable
+    private Set<String> killPlaneBlockNames;
 
     /**
      * The block types constituting this arena's kill plane
      */
-    private @Nullable Set<Material> killPlaneBlocks;
+    @Nullable
+    private Set<Material> killPlaneBlocks;
 
     /**
      * The names of the block types serving as obstacles for this arena
      */
-    private @Nullable Set<String> obstacleBlockNames;
+    @Nullable
+    private Set<String> obstacleBlockNames;
 
     /**
      * The block types serving as obstacles for this arena
      */
-    private @Nullable Set<Material> obstacleBlocks;
+    @Nullable
+    private Set<Material> obstacleBlocks;
 
     /**
      * The maximum amount of players able to join this arena at any time
@@ -94,25 +104,31 @@ public class ParkourArena implements Arena {
     /**
      * Types of damage that won't be blocked in this arena
      */
+    @NotNull
     private Set<EntityDamageEvent.DamageCause> allowedDamageCauses;
 
     /**
      * Types of damage that will trigger a loss in this arena
      */
+    @NotNull
     private Set<EntityDamageEvent.DamageCause> lossTriggerDamageCauses;
 
     /**
      * The checkpoints for this arena. Entering a checkpoint overrides the player's spawn location.
      */
-    private final @NotNull List<Location> checkpoints;
+    @NotNull
+    private final List<Location> checkpoints;
 
     /**
      * The arena data for this arena
      */
-    private final @NotNull ParkourArenaData parkourArenaData;
+    @NotNull
+    private final ParkourArenaData parkourArenaData;
 
-    private final @NotNull ParkourArenaHandler parkourArenaHandler;
+    @NotNull
+    private final ParkourArenaHandler parkourArenaHandler;
 
+    @NotNull
     private Map<RewardCondition, Set<Reward>> rewards = new HashMap<>();
 
     /**
@@ -198,27 +214,32 @@ public class ParkourArena implements Arena {
     }
 
     @Override
-    public @NotNull ParkourArenaData getData() {
+    @NotNull
+    public ParkourArenaData getData() {
         return this.parkourArenaData;
     }
 
     @Override
-    public @NotNull UUID getArenaId() {
+    @NotNull
+    public UUID getArenaId() {
         return this.arenaId;
     }
 
     @Override
-    public @NotNull String getArenaName() {
+    @NotNull
+    public String getArenaName() {
         return this.arenaName;
     }
 
     @Override
-    public @NotNull Location getSpawnLocation() {
+    @NotNull
+    public Location getSpawnLocation() {
         return this.spawnLocation;
     }
 
     @Override
-    public @Nullable Location getExitLocation() {
+    @Nullable
+    public Location getExitLocation() {
         return this.exitLocation;
     }
 
@@ -236,7 +257,8 @@ public class ParkourArena implements Arena {
     }
 
     @Override
-    public @NotNull Set<Reward> getRewards(RewardCondition rewardCondition) {
+    @NotNull
+    public Set<Reward> getRewards(@NotNull RewardCondition rewardCondition) {
         if (this.rewards.containsKey(rewardCondition)) {
             return this.rewards.get(rewardCondition);
         } else {
@@ -261,12 +283,14 @@ public class ParkourArena implements Arena {
     }
 
     @Override
-    public @NotNull Set<EntityDamageEvent.DamageCause> getAllowedDamageCauses() {
+    @NotNull
+    public Set<EntityDamageEvent.DamageCause> getAllowedDamageCauses() {
         return this.allowedDamageCauses;
     }
 
     @Override
-    public @NotNull Set<EntityDamageEvent.DamageCause> getLossTriggerDamageCauses() {
+    @NotNull
+    public Set<EntityDamageEvent.DamageCause> getLossTriggerDamageCauses() {
         return this.lossTriggerDamageCauses;
     }
 
@@ -297,7 +321,8 @@ public class ParkourArena implements Arena {
      *
      * @return <p>The win trigger's location</p>
      */
-    public @Nullable Location getWinLocation() {
+    @Nullable
+    public Location getWinLocation() {
         return this.winLocation != null ? this.winLocation.clone() : null;
     }
 
@@ -306,7 +331,8 @@ public class ParkourArena implements Arena {
      *
      * @return <p>The types of blocks that cause a loss</p>
      */
-    public @NotNull Set<Material> getKillPlaneBlocks() {
+    @NotNull
+    public Set<Material> getKillPlaneBlocks() {
         if (this.killPlaneBlocks != null) {
             return new HashSet<>(this.killPlaneBlocks);
         } else {
@@ -319,7 +345,8 @@ public class ParkourArena implements Arena {
      *
      * @return <p>The names of the types of blocks that cause a loss</p>
      */
-    public @Nullable Set<String> getKillPlaneBlockNames() {
+    @Nullable
+    public Set<String> getKillPlaneBlockNames() {
         return this.killPlaneBlockNames;
     }
 
@@ -328,7 +355,8 @@ public class ParkourArena implements Arena {
      *
      * @return <p>The types of blocks used as obstacles</p>
      */
-    public @NotNull Set<Material> getObstacleBlocks() {
+    @NotNull
+    public Set<Material> getObstacleBlocks() {
         if (this.obstacleBlocks != null) {
             return new HashSet<>(this.obstacleBlocks);
         } else {
@@ -341,7 +369,8 @@ public class ParkourArena implements Arena {
      *
      * @return <p>The names of the blocks used as this arena's obstacle blocks</p>
      */
-    public @Nullable Set<String> getObstacleBlockNames() {
+    @Nullable
+    public Set<String> getObstacleBlockNames() {
         return this.obstacleBlockNames;
     }
 
@@ -350,6 +379,7 @@ public class ParkourArena implements Arena {
      *
      * @return <p>All checkpoint locations for this arena</p>
      */
+    @NotNull
     public List<Location> getCheckpoints() {
         List<Location> copy = new ArrayList<>(this.checkpoints.size());
         for (Location location : this.checkpoints) {
@@ -569,11 +599,8 @@ public class ParkourArena implements Arena {
     }
 
     @Override
-    public boolean equals(Object other) {
-        if (!(other instanceof ParkourArena otherArena)) {
-            return false;
-        }
-        return this.getArenaNameSanitized().equals(otherArena.getArenaNameSanitized());
+    public boolean equals(@Nullable Object other) {
+        return other instanceof ParkourArena otherArena && this.getArenaNameSanitized().equals(otherArena.getArenaNameSanitized());
     }
 
 }
diff --git a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaData.java b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaData.java
index 3b5db09..aa5c9c9 100644
--- a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaData.java
+++ b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaData.java
@@ -44,7 +44,8 @@ public class ParkourArenaData extends ArenaData {
      * @return <p>The deserialized parkour arena data</p>
      */
     @SuppressWarnings({"unused", "unchecked"})
-    public static @NotNull ParkourArenaData deserialize(@NotNull Map<String, Object> data) {
+    @NotNull
+    public static ParkourArenaData deserialize(@NotNull Map<String, Object> data) {
         SerializableUUID serializableUUID = (SerializableUUID) data.get("arenaId");
         Map<ArenaGameMode, ArenaRecordsRegistry> recordsRegistry =
                 (Map<ArenaGameMode, ArenaRecordsRegistry>) data.get("recordsRegistry");
diff --git a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaEditableProperty.java b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaEditableProperty.java
index 7aad2de..fe260e7 100644
--- a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaEditableProperty.java
+++ b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaEditableProperty.java
@@ -91,8 +91,11 @@ public enum ParkourArenaEditableProperty {
             EditablePropertyType.DAMAGE_CAUSE_LIST),
     ;
 
-    private final @NotNull String argumentString;
+    @NotNull
+    private final String argumentString;
+    @NotNull
     private final Function<ParkourArena, String> currentValueProvider;
+    @NotNull
     private final EditablePropertyType propertyType;
 
     /**
@@ -100,8 +103,8 @@ public enum ParkourArenaEditableProperty {
      *
      * @param argumentString <p>The argument string used to specify this property</p>
      */
-    ParkourArenaEditableProperty(@NotNull String argumentString, Function<ParkourArena, String> currentValueProvider,
-                                 EditablePropertyType propertyType) {
+    ParkourArenaEditableProperty(@NotNull String argumentString, @NotNull Function<ParkourArena, String> currentValueProvider,
+                                 @NotNull EditablePropertyType propertyType) {
         this.argumentString = argumentString;
         this.currentValueProvider = currentValueProvider;
         this.propertyType = propertyType;
@@ -112,6 +115,7 @@ public enum ParkourArenaEditableProperty {
      *
      * @return <p>The type of this property</p>
      */
+    @NotNull
     public EditablePropertyType getPropertyType() {
         return this.propertyType;
     }
@@ -122,7 +126,8 @@ public enum ParkourArenaEditableProperty {
      * @param arena <p>The arena to check the value for</p>
      * @return <p>The current value as a string</p>
      */
-    public String getCurrentValueAsString(ParkourArena arena) {
+    @NotNull
+    public String getCurrentValueAsString(@NotNull ParkourArena arena) {
         return this.currentValueProvider.apply(arena);
     }
 
@@ -141,7 +146,8 @@ public enum ParkourArenaEditableProperty {
      * @param argumentString <p>The argument string used to specify an editable property</p>
      * @return <p>The corresponding editable property, or null if not found</p>
      */
-    public static @Nullable ParkourArenaEditableProperty getFromArgumentString(String argumentString) {
+    @Nullable
+    public static ParkourArenaEditableProperty getFromArgumentString(@NotNull String argumentString) {
         for (ParkourArenaEditableProperty property : ParkourArenaEditableProperty.values()) {
             if (property.argumentString.equalsIgnoreCase(argumentString)) {
                 return property;
diff --git a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaGameMode.java b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaGameMode.java
index 1f0aceb..cb6cd11 100644
--- a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaGameMode.java
+++ b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaGameMode.java
@@ -29,7 +29,8 @@ public enum ParkourArenaGameMode implements ConfigurationSerializable, ArenaGame
      * @param gameMode <p>The game-mode string to match</p>
      * @return <p>The specified arena game-mode</p>
      */
-    public static @NotNull ParkourArenaGameMode matchGameMode(@NotNull String gameMode) {
+    @NotNull
+    public static ParkourArenaGameMode matchGameMode(@NotNull String gameMode) {
         try {
             return ParkourArenaGameMode.valueOf(gameMode.toUpperCase());
         } catch (IllegalArgumentException exception) {
@@ -52,12 +53,14 @@ public enum ParkourArenaGameMode implements ConfigurationSerializable, ArenaGame
      * @return <p>The deserialized arena game-mode</p>
      */
     @SuppressWarnings("unused")
-    public static ParkourArenaGameMode deserialize(Map<String, Object> data) {
+    @NotNull
+    public static ParkourArenaGameMode deserialize(@NotNull Map<String, Object> data) {
         return ParkourArenaGameMode.valueOf((String) data.get("name"));
     }
 
     @Override
-    public @NotNull ParkourArenaGameMode[] getValues() {
+    @NotNull
+    public ParkourArenaGameMode[] getValues() {
         return ParkourArenaGameMode.values();
     }
 
diff --git a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaGroup.java b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaGroup.java
index e21babd..fe4898a 100644
--- a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaGroup.java
+++ b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaGroup.java
@@ -42,7 +42,8 @@ public class ParkourArenaGroup extends ArenaGroup<ParkourArena, ParkourArenaGrou
      * @return <p>The deserialized arena group</p>
      */
     @SuppressWarnings({"unused", "unchecked"})
-    public static @NotNull ParkourArenaGroup deserialize(@NotNull Map<String, Object> data) {
+    @NotNull
+    public static ParkourArenaGroup deserialize(@NotNull Map<String, Object> data) {
         UUID id = ((SerializableUUID) data.get("groupId")).getRawValue();
         String name = (String) data.get("groupName");
         List<SerializableUUID> serializableArenas = (List<SerializableUUID>) data.get("arenas");
diff --git a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaHandler.java b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaHandler.java
index ba769da..8396a2a 100644
--- a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaHandler.java
+++ b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaHandler.java
@@ -5,6 +5,7 @@ import net.knarcraft.minigames.arena.ArenaHandler;
 import net.knarcraft.minigames.arena.ArenaPlayerRegistry;
 import net.knarcraft.minigames.config.MiniGameMessage;
 import net.knarcraft.minigames.util.ParkourArenaStorageHelper;
+import org.jetbrains.annotations.NotNull;
 
 import java.io.IOException;
 import java.util.HashMap;
@@ -24,7 +25,7 @@ public class ParkourArenaHandler extends ArenaHandler<ParkourArena, ParkourArena
      *
      * @param playerRegistry <p>The registry keeping track of player sessions</p>
      */
-    public ParkourArenaHandler(ArenaPlayerRegistry<ParkourArena> playerRegistry) {
+    public ParkourArenaHandler(@NotNull ArenaPlayerRegistry<ParkourArena> playerRegistry) {
         super(playerRegistry);
     }
 
diff --git a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaPlayerRegistry.java b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaPlayerRegistry.java
index f863e18..3819e66 100644
--- a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaPlayerRegistry.java
+++ b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaPlayerRegistry.java
@@ -1,6 +1,7 @@
 package net.knarcraft.minigames.arena.parkour;
 
 import net.knarcraft.minigames.arena.AbstractArenaPlayerRegistry;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * A registry to keep track of which players are playing in which arenas
@@ -8,6 +9,7 @@ import net.knarcraft.minigames.arena.AbstractArenaPlayerRegistry;
 public class ParkourArenaPlayerRegistry extends AbstractArenaPlayerRegistry<ParkourArena> {
 
     @Override
+    @NotNull
     protected String getEntryStateStorageKey() {
         return "parkour";
     }
diff --git a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaRecordsRegistry.java b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaRecordsRegistry.java
index c6027c5..c95f2f9 100644
--- a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaRecordsRegistry.java
+++ b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaRecordsRegistry.java
@@ -51,7 +51,8 @@ public class ParkourArenaRecordsRegistry extends ArenaRecordsRegistry {
      * @return <p>The deserialized records registry</p>
      */
     @SuppressWarnings({"unused", "unchecked"})
-    public static ParkourArenaRecordsRegistry deserialize(Map<String, Object> data) {
+    @NotNull
+    public static ParkourArenaRecordsRegistry deserialize(@NotNull Map<String, Object> data) {
         UUID arenaId = ((SerializableUUID) data.get("arenaId")).getRawValue();
         Set<IntegerRecord> leastDeaths =
                 (Set<IntegerRecord>) data.getOrDefault("leastDeaths", new HashMap<>());
diff --git a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaSession.java b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaSession.java
index 615ec7d..5da7a40 100644
--- a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaSession.java
+++ b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaSession.java
@@ -33,11 +33,16 @@ import java.util.logging.Level;
  */
 public class ParkourArenaSession extends AbstractArenaSession {
 
-    private static final @NotNull Map<Arena, Set<Block>> changedLevers = new HashMap<>();
-    private final @NotNull ParkourArena arena;
-    private final @NotNull Player player;
-    private final @NotNull ParkourArenaGameMode gameMode;
-    private @Nullable Location reachedCheckpoint = null;
+    @NotNull
+    private static final Map<Arena, Set<Block>> changedLevers = new HashMap<>();
+    @NotNull
+    private final ParkourArena arena;
+    @NotNull
+    private final Player player;
+    @NotNull
+    private final ParkourArenaGameMode gameMode;
+    @Nullable
+    private Location reachedCheckpoint = null;
 
     /**
      * Instantiates a new parkour arena session
@@ -62,7 +67,8 @@ public class ParkourArenaSession extends AbstractArenaSession {
      *
      * @return <p>The game-mode for this session</p>
      */
-    public @NotNull ParkourArenaGameMode getGameMode() {
+    @NotNull
+    public ParkourArenaGameMode getGameMode() {
         return this.gameMode;
     }
 
@@ -90,12 +96,14 @@ public class ParkourArenaSession extends AbstractArenaSession {
      *
      * @return <p>The registered checkpoint, or null if not set</p>
      */
-    public @Nullable Location getRegisteredCheckpoint() {
+    @Nullable
+    public Location getRegisteredCheckpoint() {
         return this.reachedCheckpoint;
     }
 
     @Override
-    public @NotNull PlayerEntryState getEntryState() {
+    @NotNull
+    public PlayerEntryState getEntryState() {
         return this.entryState;
     }
 
@@ -139,12 +147,14 @@ public class ParkourArenaSession extends AbstractArenaSession {
     }
 
     @Override
-    public @NotNull ParkourArena getArena() {
+    @NotNull
+    public ParkourArena getArena() {
         return this.arena;
     }
 
     @Override
-    public @NotNull ArenaGUI getGUI() {
+    @NotNull
+    public ArenaGUI getGUI() {
         if (GeyserHelper.isGeyserPlayer(this.player)) {
             return new ParkourGUIBedrock(this.player);
         } else {
@@ -173,6 +183,7 @@ public class ParkourArenaSession extends AbstractArenaSession {
     }
 
     @Override
+    @NotNull
     protected String getGameModeString() {
         return switch (this.gameMode) {
             case DEFAULT -> "default";
diff --git a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaStorageKey.java b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaStorageKey.java
index d744ed9..66fa8dd 100644
--- a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaStorageKey.java
+++ b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourArenaStorageKey.java
@@ -91,7 +91,8 @@ public enum ParkourArenaStorageKey implements StorageKey {
     }
 
     @Override
-    public @NotNull String getKey() {
+    @NotNull
+    public String getKey() {
         return this.key;
     }
 
diff --git a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourPlayerEntryState.java b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourPlayerEntryState.java
index 61d54e0..271f80a 100644
--- a/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourPlayerEntryState.java
+++ b/src/main/java/net/knarcraft/minigames/arena/parkour/ParkourPlayerEntryState.java
@@ -42,10 +42,10 @@ public class ParkourPlayerEntryState extends AbstractPlayerEntryState {
      * @param originalHealth        <p>The health of the player when joining the arena</p>
      * @param originalSaturation    <p>The saturation of the player when joining the arena</p>
      */
-    public ParkourPlayerEntryState(@NotNull UUID playerId, Location entryLocation,
-                                   boolean originalIsFlying, GameMode originalGameMode, boolean originalAllowFlight,
+    public ParkourPlayerEntryState(@NotNull UUID playerId, @NotNull Location entryLocation,
+                                   boolean originalIsFlying, @NotNull GameMode originalGameMode, boolean originalAllowFlight,
                                    boolean originalInvulnerable, boolean originalIsSwimming,
-                                   boolean originalCollideAble, Collection<PotionEffect> originalPotionEffects,
+                                   boolean originalCollideAble, @NotNull Collection<PotionEffect> originalPotionEffects,
                                    double originalHealth, float originalSaturation) {
         super(playerId, entryLocation, originalIsFlying, originalGameMode, originalAllowFlight,
                 originalInvulnerable, originalIsSwimming, originalCollideAble, originalPotionEffects, originalHealth,
@@ -70,7 +70,8 @@ public class ParkourPlayerEntryState extends AbstractPlayerEntryState {
      * @return <p>The data to deserialize</p>
      */
     @SuppressWarnings({"unused", "unchecked"})
-    public static ParkourPlayerEntryState deserialize(Map<String, Object> data) {
+    @NotNull
+    public static ParkourPlayerEntryState deserialize(@NotNull Map<String, Object> data) {
         UUID playerId = ((SerializableUUID) data.get("playerId")).getRawValue();
         Location entryLocation = (Location) data.get("entryLocation");
         boolean originalIsFlying = getBoolean(data, "originalIsFlying");
diff --git a/src/main/java/net/knarcraft/minigames/arena/record/ArenaRecord.java b/src/main/java/net/knarcraft/minigames/arena/record/ArenaRecord.java
index 942c68f..935f8d5 100644
--- a/src/main/java/net/knarcraft/minigames/arena/record/ArenaRecord.java
+++ b/src/main/java/net/knarcraft/minigames/arena/record/ArenaRecord.java
@@ -3,6 +3,7 @@ package net.knarcraft.minigames.arena.record;
 import net.knarcraft.minigames.container.SerializableUUID;
 import org.bukkit.configuration.serialization.ConfigurationSerializable;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -12,16 +13,16 @@ import java.util.UUID;
 /**
  * A record stored for an arena
  */
-public abstract class ArenaRecord<K extends Comparable<K>> implements Comparable<ArenaRecord<K>>, ConfigurationSerializable {
+public abstract class ArenaRecord<RecordType extends Comparable<RecordType>> implements Comparable<ArenaRecord<RecordType>>, ConfigurationSerializable {
 
     private final UUID userId;
-    private final K record;
+    private final RecordType record;
 
     /**
      * @param userId <p>The id of the player that achieved the record</p>
      * @param record <p>The record achieved</p>
      */
-    public ArenaRecord(UUID userId, K record) {
+    public ArenaRecord(@NotNull UUID userId, @NotNull RecordType record) {
         this.userId = userId;
         this.record = record;
     }
@@ -31,6 +32,7 @@ public abstract class ArenaRecord<K extends Comparable<K>> implements Comparable
      *
      * @return <p>The record's achiever</p>
      */
+    @NotNull
     public UUID getUserId() {
         return userId;
     }
@@ -40,7 +42,8 @@ public abstract class ArenaRecord<K extends Comparable<K>> implements Comparable
      *
      * @return <p>The record value</p>
      */
-    public K getRecord() {
+    @NotNull
+    public RecordType getRecord() {
         return record;
     }
 
@@ -52,12 +55,12 @@ public abstract class ArenaRecord<K extends Comparable<K>> implements Comparable
     public abstract String getAsString();
 
     @Override
-    public boolean equals(Object other) {
+    public boolean equals(@Nullable Object other) {
         return other instanceof ArenaRecord<?> && userId.equals(((ArenaRecord<?>) other).userId);
     }
 
     @Override
-    public int compareTo(@NotNull ArenaRecord<K> other) {
+    public int compareTo(@NotNull ArenaRecord<RecordType> other) {
         return record.compareTo(other.record);
     }
 
diff --git a/src/main/java/net/knarcraft/minigames/arena/record/IntegerRecord.java b/src/main/java/net/knarcraft/minigames/arena/record/IntegerRecord.java
index ba7bb6e..76a422d 100644
--- a/src/main/java/net/knarcraft/minigames/arena/record/IntegerRecord.java
+++ b/src/main/java/net/knarcraft/minigames/arena/record/IntegerRecord.java
@@ -2,6 +2,7 @@ package net.knarcraft.minigames.arena.record;
 
 import net.knarcraft.minigames.container.SerializableUUID;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.Map;
 import java.util.UUID;
@@ -12,25 +13,29 @@ import java.util.UUID;
 public class IntegerRecord extends SummableArenaRecord<Integer> {
 
     /**
+     * Instantiates a new integer record
+     *
      * @param userId <p>The id of the player that achieved the record</p>
      * @param record <p>The record achieved</p>
      */
-    public IntegerRecord(UUID userId, Integer record) {
+    public IntegerRecord(@NotNull UUID userId, @NotNull Integer record) {
         super(userId, record);
     }
 
     @Override
+    @NotNull
     public String getAsString() {
         return String.valueOf(this.getRecord());
     }
 
     @Override
-    public SummableArenaRecord<Integer> sum(Integer value) {
+    @NotNull
+    public SummableArenaRecord<Integer> sum(@NotNull Integer value) {
         return new IntegerRecord(this.getUserId(), this.getRecord() + value);
     }
 
     @Override
-    public boolean equals(Object other) {
+    public boolean equals(@Nullable Object other) {
         return other instanceof IntegerRecord && this.getUserId().equals(((IntegerRecord) other).getUserId());
     }
 
@@ -41,6 +46,7 @@ public class IntegerRecord extends SummableArenaRecord<Integer> {
      * @return <p>The deserialized data</p>
      */
     @SuppressWarnings("unused")
+    @NotNull
     public static IntegerRecord deserialize(@NotNull Map<String, Object> data) {
         return new IntegerRecord(((SerializableUUID) data.get("userId")).getRawValue(), (Integer) data.get("record"));
     }
diff --git a/src/main/java/net/knarcraft/minigames/arena/record/LongRecord.java b/src/main/java/net/knarcraft/minigames/arena/record/LongRecord.java
index 547a2fd..44edd29 100644
--- a/src/main/java/net/knarcraft/minigames/arena/record/LongRecord.java
+++ b/src/main/java/net/knarcraft/minigames/arena/record/LongRecord.java
@@ -2,6 +2,7 @@ package net.knarcraft.minigames.arena.record;
 
 import net.knarcraft.minigames.container.SerializableUUID;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.Map;
 import java.util.UUID;
@@ -12,24 +13,28 @@ import java.util.UUID;
 public class LongRecord extends SummableArenaRecord<Long> {
 
     /**
+     * Instantiates a new long record
+     *
      * @param userId <p>The id of the player that achieved the record</p>
      * @param record <p>The record achieved</p>
      */
-    public LongRecord(UUID userId, Long record) {
+    public LongRecord(@NotNull UUID userId, @NotNull Long record) {
         super(userId, record);
     }
 
     @Override
-    public boolean equals(Object other) {
+    public boolean equals(@Nullable Object other) {
         return other instanceof LongRecord && this.getUserId().equals(((LongRecord) other).getUserId());
     }
 
     @Override
-    public SummableArenaRecord<Long> sum(Long value) {
+    @NotNull
+    public SummableArenaRecord<Long> sum(@NotNull Long value) {
         return new LongRecord(this.getUserId(), this.getRecord() + value);
     }
 
     @Override
+    @NotNull
     public String getAsString() {
         double seconds = getRecord() / 1000.0;
         double minutes = 0;
@@ -52,6 +57,7 @@ public class LongRecord extends SummableArenaRecord<Long> {
      * @return <p>The deserialized data</p>
      */
     @SuppressWarnings("unused")
+    @NotNull
     public static LongRecord deserialize(@NotNull Map<String, Object> data) {
         return new LongRecord(((SerializableUUID) data.get("userId")).getRawValue(),
                 ((Number) data.get("record")).longValue());
diff --git a/src/main/java/net/knarcraft/minigames/arena/record/SummableArenaRecord.java b/src/main/java/net/knarcraft/minigames/arena/record/SummableArenaRecord.java
index 9c0ead6..7bebb17 100644
--- a/src/main/java/net/knarcraft/minigames/arena/record/SummableArenaRecord.java
+++ b/src/main/java/net/knarcraft/minigames/arena/record/SummableArenaRecord.java
@@ -1,19 +1,21 @@
 package net.knarcraft.minigames.arena.record;
 
+import org.jetbrains.annotations.NotNull;
+
 import java.util.UUID;
 
 /**
  * A type of arena record which can be summed together
  *
- * @param <K> <p>The type of the stored value</p>
+ * @param <RecordType> <p>The type of the stored value</p>
  */
-public abstract class SummableArenaRecord<K extends Comparable<K>> extends ArenaRecord<K> {
+public abstract class SummableArenaRecord<RecordType extends Comparable<RecordType>> extends ArenaRecord<RecordType> {
 
     /**
      * @param userId <p>The id of the player that achieved the record</p>
      * @param record <p>The record achieved</p>
      */
-    public SummableArenaRecord(UUID userId, K record) {
+    public SummableArenaRecord(@NotNull UUID userId, @NotNull RecordType record) {
         super(userId, record);
     }
 
@@ -23,6 +25,7 @@ public abstract class SummableArenaRecord<K extends Comparable<K>> extends Arena
      * @param value <p>The value to add to the existing value</p>
      * @return <p>A record with the sum of this record and the given value</p>
      */
-    public abstract SummableArenaRecord<K> sum(K value);
+    @NotNull
+    public abstract SummableArenaRecord<RecordType> sum(@NotNull RecordType value);
 
 }
diff --git a/src/main/java/net/knarcraft/minigames/arena/reward/CommandReward.java b/src/main/java/net/knarcraft/minigames/arena/reward/CommandReward.java
index bfa3d70..0538753 100644
--- a/src/main/java/net/knarcraft/minigames/arena/reward/CommandReward.java
+++ b/src/main/java/net/knarcraft/minigames/arena/reward/CommandReward.java
@@ -31,7 +31,8 @@ public class CommandReward implements Reward {
     }
 
     @Override
-    public @NotNull FormatBuilder getGrantMessage() {
+    @NotNull
+    public FormatBuilder getGrantMessage() {
         return new FormatBuilder(MiniGameMessage.SUCCESS_COMMAND_REWARDED).replace("{command}", command);
     }
 
@@ -50,6 +51,7 @@ public class CommandReward implements Reward {
      * @param input  <p>The input containing a name placeholder</p>
      * @return <p>The input with the placeholder replaced</p>
      */
+    @NotNull
     private String replaceNamePlaceholder(@NotNull Player player, @NotNull String input) {
         return input.replaceAll("[<%(\\[{]player[_\\-]?(name)?[>%)\\]}]", player.getName());
     }
@@ -61,7 +63,8 @@ public class CommandReward implements Reward {
      * @return <p>The deserialized data</p>
      */
     @SuppressWarnings("unused")
-    public static CommandReward deserialize(Map<String, Object> data) {
+    @NotNull
+    public static CommandReward deserialize(@NotNull Map<String, Object> data) {
         return new CommandReward((String) data.get("command"));
     }
 
diff --git a/src/main/java/net/knarcraft/minigames/arena/reward/EconomyReward.java b/src/main/java/net/knarcraft/minigames/arena/reward/EconomyReward.java
index 193d0dc..e001764 100644
--- a/src/main/java/net/knarcraft/minigames/arena/reward/EconomyReward.java
+++ b/src/main/java/net/knarcraft/minigames/arena/reward/EconomyReward.java
@@ -39,7 +39,8 @@ public class EconomyReward implements Reward {
     }
 
     @Override
-    public @NotNull FormatBuilder getGrantMessage() {
+    @NotNull
+    public FormatBuilder getGrantMessage() {
         return new FormatBuilder(MiniGameMessage.SUCCESS_ECONOMY_REWARDED).replace("{currency}",
                 EconomyManager.format(amount));
     }
@@ -59,7 +60,8 @@ public class EconomyReward implements Reward {
      * @return <p>The deserialized data</p>
      */
     @SuppressWarnings("unused")
-    public static EconomyReward deserialize(Map<String, Object> data) {
+    @NotNull
+    public static EconomyReward deserialize(@NotNull Map<String, Object> data) {
         return new EconomyReward((Double) data.get("amount"));
     }
 
diff --git a/src/main/java/net/knarcraft/minigames/arena/reward/ItemReward.java b/src/main/java/net/knarcraft/minigames/arena/reward/ItemReward.java
index 3ea5f8a..bfc6cf7 100644
--- a/src/main/java/net/knarcraft/minigames/arena/reward/ItemReward.java
+++ b/src/main/java/net/knarcraft/minigames/arena/reward/ItemReward.java
@@ -43,7 +43,8 @@ public class ItemReward implements Reward {
     }
 
     @Override
-    public @NotNull FormatBuilder getGrantMessage() {
+    @NotNull
+    public FormatBuilder getGrantMessage() {
         NamespacedKey key = item.getType().getKeyOrNull();
         String name = key == null ? "Unnamed item" : key.getKey().replace("_", " ");
         return new FormatBuilder(MiniGameMessage.SUCCESS_ITEM_REWARDED).
@@ -65,7 +66,8 @@ public class ItemReward implements Reward {
      * @return <p>The deserialized data</p>
      */
     @SuppressWarnings("unused")
-    public static ItemReward deserialize(Map<String, Object> data) {
+    @NotNull
+    public static ItemReward deserialize(@NotNull Map<String, Object> data) {
         return new ItemReward((ItemStack) data.get("item"));
     }
 
@@ -75,7 +77,7 @@ public class ItemReward implements Reward {
      * @param inventory <p>The inventory to check</p>
      * @return <p>True if the inventory can fit the item</p>
      */
-    private boolean canFitItem(Inventory inventory) {
+    private boolean canFitItem(@NotNull Inventory inventory) {
         // If a slot is available, there is no problem
         if (inventory.firstEmpty() != -1) {
             return true;
diff --git a/src/main/java/net/knarcraft/minigames/arena/reward/PermissionReward.java b/src/main/java/net/knarcraft/minigames/arena/reward/PermissionReward.java
index 095a5ab..51bd5b0 100644
--- a/src/main/java/net/knarcraft/minigames/arena/reward/PermissionReward.java
+++ b/src/main/java/net/knarcraft/minigames/arena/reward/PermissionReward.java
@@ -48,7 +48,8 @@ public class PermissionReward implements Reward {
     }
 
     @Override
-    public @NotNull FormatBuilder getGrantMessage() {
+    @NotNull
+    public FormatBuilder getGrantMessage() {
         if (world == null) {
             return new FormatBuilder(MiniGameMessage.SUCCESS_PERMISSION_REWARDED).replace("{permission}",
                     permission);
@@ -76,7 +77,8 @@ public class PermissionReward implements Reward {
      * @return <p>The deserialized data</p>
      */
     @SuppressWarnings("unused")
-    public static PermissionReward deserialize(Map<String, Object> data) {
+    @NotNull
+    public static PermissionReward deserialize(@NotNull Map<String, Object> data) {
         World world = (World) data.getOrDefault("world", null);
         String permission = (String) data.get("permission");
         return new PermissionReward(world, permission);
diff --git a/src/main/java/net/knarcraft/minigames/arena/reward/RewardCondition.java b/src/main/java/net/knarcraft/minigames/arena/reward/RewardCondition.java
index 4c8693e..9916a44 100644
--- a/src/main/java/net/knarcraft/minigames/arena/reward/RewardCondition.java
+++ b/src/main/java/net/knarcraft/minigames/arena/reward/RewardCondition.java
@@ -50,7 +50,8 @@ public enum RewardCondition implements ConfigurationSerializable {
      * @param condition <p>The string specifying a reward condition</p>
      * @return <p>The matching reward condition, or null if not found</p>
      */
-    public static @Nullable RewardCondition getFromString(@NotNull String condition) {
+    @Nullable
+    public static RewardCondition getFromString(@NotNull String condition) {
         for (RewardCondition rewardCondition : RewardCondition.values()) {
             if (rewardCondition.name().equalsIgnoreCase(condition.replace("-", "_"))) {
                 return rewardCondition;
@@ -75,7 +76,8 @@ public enum RewardCondition implements ConfigurationSerializable {
      * @return <p>The deserialized reward condition</p>
      */
     @SuppressWarnings({"unused"})
-    public static @NotNull RewardCondition deserialize(@NotNull Map<String, Object> data) {
+    @NotNull
+    public static RewardCondition deserialize(@NotNull Map<String, Object> data) {
         RewardCondition rewardCondition = getFromString(String.valueOf(data.get("condition")));
         return Objects.requireNonNullElse(rewardCondition, RewardCondition.FIRST_WIN);
     }
diff --git a/src/main/java/net/knarcraft/minigames/arena/reward/RewardType.java b/src/main/java/net/knarcraft/minigames/arena/reward/RewardType.java
index c3778ca..acdac1d 100644
--- a/src/main/java/net/knarcraft/minigames/arena/reward/RewardType.java
+++ b/src/main/java/net/knarcraft/minigames/arena/reward/RewardType.java
@@ -1,6 +1,7 @@
 package net.knarcraft.minigames.arena.reward;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * The type of a specific reward
@@ -34,6 +35,7 @@ public enum RewardType {
      * @param condition <p>The string specifying a reward type</p>
      * @return <p>The matching reward type, or null if not found</p>
      */
+    @Nullable
     public static RewardType getFromString(@NotNull String condition) {
         for (RewardType rewardType : RewardType.values()) {
             if (rewardType.name().equalsIgnoreCase(condition.replace("-", "_"))) {