diff --git a/src/main/java/net/minestom/server/instance/Chunk.java b/src/main/java/net/minestom/server/instance/Chunk.java
index 6c2ddaef7..3d5669ea4 100644
--- a/src/main/java/net/minestom/server/instance/Chunk.java
+++ b/src/main/java/net/minestom/server/instance/Chunk.java
@@ -48,7 +48,7 @@ public abstract class Chunk implements Viewable, DataContainer {
 
     public static final int CHUNK_SECTION_COUNT = CHUNK_SIZE_Y / CHUNK_SECTION_SIZE;
 
-    public static final int BIOME_COUNT = 1024; // 4x4x4 blocks
+    public static final int BIOME_COUNT = 1024; // 4x4x4 blocks group
 
     protected final Instance instance;
     protected Biome[] biomes;
@@ -58,7 +58,7 @@ public abstract class Chunk implements Viewable, DataContainer {
     // Key is still chunk coord
     protected Int2ObjectMap<Data> blocksData = new Int2ObjectOpenHashMap<>(16 * 16); // Start with the size of a single row
 
-    // Contains CustomBlocks' index which are updatable
+    // Contains CustomBlocks' block index which are updatable
     protected IntSet updatableBlocks = new IntOpenHashSet();
     // (block index)/(last update in ms)
     protected Int2LongMap updatableBlocksLastUpdate = new Int2LongOpenHashMap();
@@ -178,13 +178,13 @@ public abstract class Chunk implements Viewable, DataContainer {
     /**
      * Change the block state id and the custom block id at a position
      *
-     * @param x            the block X
-     * @param y            the block Y
-     * @param z            the block Z
-     * @param blockStateId the new block state id
-     * @param customId     the new custom block id
+     * @param x             the block X
+     * @param y             the block Y
+     * @param z             the block Z
+     * @param blockStateId  the new block state id
+     * @param customBlockId the new custom block id
      */
-    protected abstract void refreshBlockValue(int x, int y, int z, short blockStateId, short customId);
+    protected abstract void refreshBlockValue(int x, int y, int z, short blockStateId, short customBlockId);
 
     /**
      * Change the block state id at a position (the custom block id stays the same)
@@ -339,7 +339,7 @@ public abstract class Chunk implements Viewable, DataContainer {
     /**
      * Serialize the chunk into bytes
      *
-     * @return the serialized chunk, can potentially be null if this chunk cannot be serialized
+     * @return the serialized chunk, can be null if this chunk cannot be serialized
      */
     public abstract byte[] getSerializedData();
 
diff --git a/src/main/java/net/minestom/server/instance/DynamicChunk.java b/src/main/java/net/minestom/server/instance/DynamicChunk.java
index 590e50f2d..6c71ad4c0 100644
--- a/src/main/java/net/minestom/server/instance/DynamicChunk.java
+++ b/src/main/java/net/minestom/server/instance/DynamicChunk.java
@@ -111,14 +111,14 @@ public class DynamicChunk extends Chunk {
     }
 
     @Override
-    protected void refreshBlockValue(int x, int y, int z, short blockStateId, short customId) {
+    protected void refreshBlockValue(int x, int y, int z, short blockStateId, short customBlockId) {
         final int blockIndex = getBlockIndex(x, y, z);
         if (!MathUtils.isBetween(blockIndex, 0, blocksStateId.length)) {
             return;
         }
 
         this.blocksStateId[blockIndex] = blockStateId;
-        this.customBlocksId[blockIndex] = customId;
+        this.customBlocksId[blockIndex] = customBlockId;
     }
 
     @Override
@@ -161,6 +161,7 @@ public class DynamicChunk extends Chunk {
             binaryWriter.writeByte(id);
         }
 
+        // Loop all blocks
         for (byte x = 0; x < CHUNK_SIZE_X; x++) {
             for (short y = 0; y < CHUNK_SIZE_Y; y++) {
                 for (byte z = 0; z < CHUNK_SIZE_Z; z++) {
@@ -230,11 +231,13 @@ public class DynamicChunk extends Chunk {
                 serializableData.readSerializedData(reader, typeToIndexMap);
             }
 
+            // Biomes
             for (int i = 0; i < BIOME_COUNT; i++) {
                 final byte id = reader.readByte();
                 this.biomes[i] = BIOME_MANAGER.getById(id);
             }
 
+            // Loop for all blocks in the chunk
             while (true) {
                 // Position
                 final short index = reader.readShort();
diff --git a/src/main/java/net/minestom/server/instance/Instance.java b/src/main/java/net/minestom/server/instance/Instance.java
index 7857e23a4..06ea281ad 100644
--- a/src/main/java/net/minestom/server/instance/Instance.java
+++ b/src/main/java/net/minestom/server/instance/Instance.java
@@ -964,17 +964,16 @@ public abstract class Instance implements BlockModifier, EventHandler, DataConta
      * Creates an explosion at the given position with the given strength.
      * The algorithm used to compute damages is provided by {@link #getExplosionSupplier()}.
      *
-     * @param centerX
-     * @param centerY
-     * @param centerZ
-     * @param strength
+     * @param centerX        center X of the explosion
+     * @param centerY        center Y of the explosion
+     * @param centerZ        center Z of the explosion
+     * @param strength       the strength of the explosion
      * @param additionalData data to pass to the explosion supplier
      * @throws IllegalStateException If no {@link ExplosionSupplier} was supplied
      */
     public void explode(float centerX, float centerY, float centerZ, float strength, Data additionalData) {
         final ExplosionSupplier explosionSupplier = getExplosionSupplier();
-        if (explosionSupplier == null)
-            throw new IllegalStateException("Tried to create an explosion with no explosion supplier");
+        Check.stateCondition(explosionSupplier == null, "Tried to create an explosion with no explosion supplier");
         final Explosion explosion = explosionSupplier.createExplosion(centerX, centerY, centerZ, strength, additionalData);
         explosion.apply(this);
     }
@@ -989,7 +988,7 @@ public abstract class Instance implements BlockModifier, EventHandler, DataConta
     }
 
     /**
-     * Registers the explosion supplier to use in this instance
+     * Registers the {@link ExplosionSupplier} to use in this instance
      *
      * @param supplier the explosion supplier
      */