Bugfixes to the RevID update system:

+ Option to not reroll RNG stats actually works now.

 Bugfixes to item skins:
  + Skin source information no longer lost when MMOItem is read from an Item Stack (would cause it to be lost when RevID updating even if keep skins was enabled).

src/main/java/net/Indyuce/mmoitems/api/interaction/ItemSkin.java

@@ -92,6 +92,9 @@ public class ItemSkin extends UseItem {
 		return new ApplyResult(item);
 	}
 
+	public static final String tagHasSkin = "MMOITEMS_HAS_SKIN";
+	public static final String tagSkinID = "MMOITEMS_SKIN_ID";
+
 	/**
 	 * Applies the skin information from a skin consumable onto any item.
 	 *
@@ -104,16 +107,15 @@ public class ItemSkin extends UseItem {
 	 */
 	@NotNull public static ItemStack applySkin(@NotNull NBTItem target, @NotNull NBTItem skinItemNBT, @NotNull MMOItem skinItemMMO) {
 
-		target.addTag(new ItemTag("MMOITEMS_HAS_SKIN", true));
-		target.addTag(new ItemTag("MMOITEMS_SKIN_ID", skinItemNBT.getString("MMOITEMS_ITEM_ID")));
+		target.addTag(new ItemTag(tagHasSkin, true));
+		target.addTag(new ItemTag(tagSkinID, skinItemNBT.getString(tagSkinID)));
 		if (skinItemNBT.getInteger("CustomModelData") != 0) {
 			target.addTag(new ItemTag("CustomModelData", skinItemNBT.getInteger("CustomModelData"))); }
 		if (!skinItemNBT.getString("MMOITEMS_ITEM_PARTICLES").isEmpty()) {
 			target.addTag(new ItemTag("MMOITEMS_ITEM_PARTICLES", skinItemNBT.getString("MMOITEMS_ITEM_PARTICLES"))); }
 
 		ItemStack item = target.toItem();
-		if (item.getType() != skinItemNBT.getItem().getType())
-			item.setType(skinItemNBT.getItem().getType());
+		if (item.getType() != skinItemNBT.getItem().getType()) { item.setType(skinItemNBT.getItem().getType()); }
 
 		ItemMeta meta = item.getItemMeta();
 		ItemMeta skinMeta = skinItemNBT.getItem().getItemMeta();

src/main/java/net/Indyuce/mmoitems/listener/reforging/RFFKeepSkins.java

@@ -24,7 +24,7 @@ public class RFFKeepSkins implements Listener {
         //RFG// MMOItems.log("§8Reforge §4EFG§7 Keeping Skins");
 
         // Got skin?
-        if (!event.getReforger().getNBTItem().getBoolean("MMOITEMS_HAS_SKIN")) { return; }
+        if (!event.getReforger().getNBTItem().getBoolean(ItemSkin.tagHasSkin)) { return; }
         //RFG// MMOItems.log("§8Reforge §4EFG§7 Item has skin");
 
         // Apply skin to result

src/main/java/net/Indyuce/mmoitems/listener/reforging/RFGKeepRNG.java

@@ -9,6 +9,7 @@ import net.Indyuce.mmoitems.stat.data.type.Mergeable;
 import net.Indyuce.mmoitems.stat.data.type.StatData;
 import net.Indyuce.mmoitems.stat.type.ItemStat;
 import net.Indyuce.mmoitems.stat.type.StatHistory;
+import org.bukkit.event.EventHandler;
 import org.bukkit.event.Listener;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -21,11 +22,15 @@ import org.jetbrains.annotations.Nullable;
  */
 public class RFGKeepRNG implements Listener {
 
+    @EventHandler
     public void onReforge(MMOItemReforgeEvent event) {
 
         // Rerolling stats? Nevermind
-        if (event.getOptions().shouldReroll()) { return; }
-        //RFG// MMOItems.log("§8Reforge §4EFG§7 Keeping RNG Rolls");
+        if (event.getOptions().shouldReroll()) {
+            //RFG// MMOItems.log("§8Reforge §4EFG§7 Keeping new item (Complete RNG Reroll)");
+            return; }
+
+        //RFG// MMOItems.log("§8Reforge §4EFG§7 Keeping old RNG Rolls");
 
         /*
          * Proceed to go through all stats
@@ -33,7 +38,9 @@ public class RFGKeepRNG implements Listener {
         for (ItemStat stat : event.getOldMMOItem().getStats()) {
 
             // Skip if it cant merge
-            if (!(stat.getClearStatData() instanceof Mergeable)) { continue; }
+            if (!(stat.getClearStatData() instanceof Mergeable)) {
+                //RFG// MMOItems.log("§8Reforge §3RNG§7 Stat\u00a7f " + stat.getId() + "\u00a77 is \u00a7cnot\u00a77 even mergeable");
+                continue; }
 
             /*
              * These stats are exempt from this 'keeping' operation.
@@ -46,18 +53,26 @@ public class RFGKeepRNG implements Listener {
                     ItemStats.ENCHANTS.equals(stat) ||
                     ItemStats.SOULBOUND.equals(stat) ||
                     ItemStats.GEM_SOCKETS.equals(stat)) {
-
+                //RFG// MMOItems.log("§8Reforge §3RNG§7 Stat\u00a7f " + stat.getId() + "\u00a77 is \u00a7cnot\u00a77 processed here");
                 continue; }
 
+            //RFG// MMOItems.log("§8Reforge §3RNG§7 Stat\u00a7f " + stat.getId() + "\u00a77 being \u00a7bprocessed\u00a77...");
+
             // Stat history in the old item
             StatHistory hist = StatHistory.from(event.getOldMMOItem(), stat);
 
             // Alr what the template say, this roll too rare to be kept?
             RandomStatData source = event.getReforger().getTemplate().getBaseItemData().get(stat);
+
+            /*
+             * Decide if this data is too far from RNG to
+             * preserve its rolls, even if it should be
+             * preserving the rolls.
+             */
             StatData keptData = shouldRerollRegardless(stat, source, hist.getOriginalData(), event.getReforger().getGenerationItemLevel());
 
             // Old roll is ridiculously low probability under the new parameters. Forget.
-            if (keptData == null) { return; }
+            if (keptData == null) { continue; }
 
             // Fetch History from the new item
             StatHistory clear = StatHistory.from(event.getNewMMOItem(), stat);
@@ -72,18 +87,23 @@ public class RFGKeepRNG implements Listener {
      *
      * 		   In contrast to reforging, in which it is expected its RNG to be rerolled, updating should not do it
      * 		   except in the most dire scenarios:
+     * 		   <br><br>
      * 		    + The mean/standard deviation changing significantly:
      * 		    	If the chance of getting the same roll is ridiculously low (3.5SD) under the new settings, reroll.
-     *
-     * 		    + The stat is no longer there, or a new stat was added
-     * 		       The chance of getting a roll of 0 will be evaluated per the rule above.
+     *         <br><br>
+     * 		    + The stat is no longer there: Mean and SD become zero, so the rule above always removes the old roll.
+     *         <br><br>
+     * 		    + There is a new stat: The original data is null so this method cannot be called, will roll the
+     * 		        new stat to actually add it for the first time.
      *
      *
      */
     @Nullable StatData shouldRerollRegardless(@NotNull ItemStat stat, @NotNull RandomStatData source, @NotNull StatData original, int determinedItemLevel) {
 
         // Not Mergeable, impossible to keep
-        if (!(source instanceof UpdatableRandomStatData)) { return null; }
+        if (!(source instanceof UpdatableRandomStatData)) {
+            //RFG// MMOItems.log("§8Reforge §3RNG§7 Stat\u00a7f " + stat.getId() + "\u00a77 is not updatable!");
+            return null; }
 
         // Just pass on
         return ((UpdatableRandomStatData) source).reroll(stat, original, determinedItemLevel);

src/main/java/net/Indyuce/mmoitems/stat/data/StoredTagsData.java

@@ -2,6 +2,7 @@ package net.Indyuce.mmoitems.stat.data;
 
 import io.lumine.mythic.lib.api.item.ItemTag;
 import io.lumine.mythic.lib.api.item.NBTItem;
+import net.Indyuce.mmoitems.api.interaction.ItemSkin;
 import net.Indyuce.mmoitems.api.item.build.ItemStackBuilder;
 import net.Indyuce.mmoitems.stat.data.type.Mergeable;
 import net.Indyuce.mmoitems.stat.data.type.StatData;
@@ -44,9 +45,22 @@ public class StoredTagsData implements StatData, Mergeable {
 
 	public StoredTagsData(NBTItem nbt) {
 		for (String tag : nbt.getTags()) {
+
+			// Usually ignore mmoitems
+			if (tag.startsWith("MMOITEMS_")) {
+
+				// Do not delete the skin tags (save them here)
+				if (!ItemSkin.tagHasSkin.equals(tag) && !ItemSkin.tagSkinID.equals(tag)) {
+
+					// Not either of the skin tags, skip this.
+					// Must be handled by its respective stat.
+					continue;
+				}
+			}
+
 			// Any vanilla or MMOItem tag should be ignored as those are
 			// automatically handled. Same for the History stat ones.
-			if (ignoreList.contains(tag) || tag.startsWith("MMOITEMS_") || tag.startsWith(ItemStackBuilder.history_keyword))
+			if (ignoreList.contains(tag) || tag.startsWith(ItemStackBuilder.history_keyword))
 				continue;
 
 			// As more methods are added we can add more types here

src/main/java/net/Indyuce/mmoitems/stat/data/random/UpdatableRandomStatData.java

@@ -32,8 +32,9 @@ public interface UpdatableRandomStatData {
      *
      * @param determinedItemLevel The level of the item
      *
-     * @return The rerolled StatData if the original is unreasonable, but if it must be kept,
-     *         it should be a clone of the original, probably using {@link Mergeable#cloneData()}
+     * @return The rerolled StatData if the original is unreasonable.
+     *         <br><br>
+     *         If the original is reasonable, a clone of it, probably using {@link Mergeable#cloneData()}
      */
     @NotNull <T extends StatData> T reroll(@NotNull ItemStat stat, @NotNull T original, int determinedItemLevel);
 }

src/main/resources/config.yml

@@ -247,6 +247,23 @@ permissions:
     abilities: false
     items: true
 
+#
+# When item stats has a numeric range of possibilities.
+# attack-damage:
+#    base: 10
+#    spread: 1
+#
+# Using the spread, a level, and a random number, we
+# obtain a random number (very related to the spread): 1.7
+#
+# If additive-spread-formula is true, this is added to the base:
+#    RESULT: 10 + 1.7  =  11.7 attack damage
+#
+# If additive-spread-formula is false, this is multiplied to the base:
+#    RESULT: 10 * 1.7  =  17 attack damage
+#
+additive-spread-formula: false
+
 # Disables non MMOItems from being crafted in the vanilla workbench.
 # Add [] if the list is empty.
 disable-vanilla-recipes: []