diff --git a/src/player/malte/Item.java b/src/player/malte/Item.java
index b203025..e28e1cb 100644
--- a/src/player/malte/Item.java
+++ b/src/player/malte/Item.java
@@ -1,15 +1,43 @@
 package player.malte;
 
+/**
+ * An item of a pattern for the game of Connect Four.
+ */
 public class Item {
 
+    /**
+     * The relative horizontal position of the item.
+     */
     private int posX;
+
+    /**
+     * The relative vertical position of the item.
+     */
     private int posY;
+
+    /**
+     * The IDs this item recognizes valid.
+     */
     private int[] ids;
 
+    /**
+     * Basic constructor.
+     *
+     * @param posX Relative horizontal position.
+     * @param posY Relative vertical position.
+     * @param The accepted id.
+     */
     public Item(int posX, int posY, int id) {
         this(posX, posY, new int[]{id});
     }
 
+    /**
+     * Basic constructor for multiple IDs.
+     *
+     * @param posX Relative horizontal position.
+     * @param posY Relative vertical position.
+     * @param The accepted IDs.
+     */
     public Item(int posX, int posY, int[] ids) {
         this.posX = posX;
         this.posY = posY;
@@ -37,12 +65,22 @@ public class Item {
         return false;
     }
 
+    /**
+     * Changes the given oldID to the newID.
+     * If newID already exists, do nothing.
+     * IF oldID does not exist, do nothing.
+     *
+     * @param oldID The ID to be replaced.
+     * @param newID The new ID.
+     */
     public void changeID(int oldID, int newID) {
+        // If the ID already exists, do nothing.
         for (int id: ids) {
             if (id == newID) {
                 return;
             }
         }
+        // Otherwise replace it, if oldID exists.
         for (int i = 0; i < ids.length; i++) {
             if (ids[i] == oldID) {
                 ids[i] = newID;
@@ -60,6 +98,11 @@ public class Item {
         return s + "])";
     }
 
+    /**
+     * Returns a deep copy of the item.
+     *
+     * @return A deep copy of this element.
+     */
     public Item copy() {
         return new Item(posX, posY, ids);
     }