diff --git a/Minecraft.World/IO/NBT/ByteArrayTag.h b/Minecraft.World/IO/NBT/ByteArrayTag.h
index d43c43d97..fe9aa6597 100644
--- a/Minecraft.World/IO/NBT/ByteArrayTag.h
+++ b/Minecraft.World/IO/NBT/ByteArrayTag.h
@@ -5,18 +5,24 @@
 class ByteArrayTag : public Tag {
 public:
     byteArray data;
+    bool m_ownData;
 
-    ByteArrayTag(const std::wstring& name) : Tag(name) {}
-    ByteArrayTag(const std::wstring& name, byteArray data) : Tag(name) {
+    ByteArrayTag(const std::wstring& name) : Tag(name) { m_ownData = false; }
+    ByteArrayTag(const std::wstring& name, byteArray data, bool ownData = false)
+        : Tag(name) {
         this->data = data;
+        m_ownData = ownData;
     }  // 4J - added ownData param
+    ~ByteArrayTag() {
+        if (m_ownData) delete[] data.data;
+    }
 
     void write(DataOutput* dos) {
         dos->writeInt(data.length);
         dos->write(data);
     }
 
-    void load(DataInput* dis) {
+    void load(DataInput* dis, int tagDepth) {
         int length = dis->readInt();
 
         if (data.data) delete[] data.data;
@@ -45,6 +51,6 @@ public:
     Tag* copy() {
         byteArray cp = byteArray(data.length);
         System::arraycopy(data, 0, &cp, 0, data.length);
-        return new ByteArrayTag(getName(), cp);
+        return new ByteArrayTag(getName(), cp, true);
     }
 };
\ No newline at end of file
diff --git a/Minecraft.World/IO/NBT/ByteTag.h b/Minecraft.World/IO/NBT/ByteTag.h
index 6285eb7f9..33d8929ba 100644
--- a/Minecraft.World/IO/NBT/ByteTag.h
+++ b/Minecraft.World/IO/NBT/ByteTag.h
@@ -10,7 +10,7 @@ public:
     }
 
     void write(DataOutput* dos) { dos->writeByte(data); }
-    void load(DataInput* dis) { data = dis->readByte(); }
+    void load(DataInput* dis, int tagDepth) { data = dis->readByte(); }
 
     uint8_t getId() { return TAG_Byte; }
     std::wstring toString() {
diff --git a/Minecraft.World/IO/NBT/CompoundTag.h b/Minecraft.World/IO/NBT/CompoundTag.h
index bc3e0bf6a..f30adf82d 100644
--- a/Minecraft.World/IO/NBT/CompoundTag.h
+++ b/Minecraft.World/IO/NBT/CompoundTag.h
@@ -28,7 +28,15 @@ public:
         dos->writeByte(Tag::TAG_End);
     }
 
-    void load(DataInput* dis) {
+    void load(DataInput* dis, int tagDepth) {
+        if (tagDepth > MAX_DEPTH) {
+#ifndef _CONTENT_PACKAGE
+            printf("Tried to read NBT tag with too high complexity, depth > %d",
+                   MAX_DEPTH);
+            __debugbreak();
+#endif
+            return;
+        }
         tags.clear();
         Tag* tag;
         while ((tag = Tag::readNamedTag(dis))->getId() != Tag::TAG_End) {
@@ -52,123 +60,121 @@ public:
 
     uint8_t getId() { return TAG_Compound; }
 
-    void put(const wchar_t* name, Tag* tag) {
-        tags[name] = tag->setName(std::wstring(name));
+    void put(const std::wstring& name, Tag* tag) {
+        tags[name] = tag->setName(name);
     }
 
-    void putByte(const wchar_t* name, uint8_t value) {
+    void putByte(const std::wstring& name, uint8_t value) {
         tags[name] = (new ByteTag(name, value));
     }
 
-    void putShort(const wchar_t* name, short value) {
+    void putShort(const std::wstring& name, short value) {
         tags[name] = (new ShortTag(name, value));
     }
 
-    void putInt(const wchar_t* name, int value) {
+    void putInt(const std::wstring& name, int value) {
         tags[name] = (new IntTag(name, value));
     }
 
-    void putLong(const wchar_t* name, int64_t value) {
+    void putLong(const std::wstring& name, int64_t value) {
         tags[name] = (new LongTag(name, value));
     }
 
-    void putFloat(const wchar_t* name, float value) {
+    void putFloat(const std::wstring& name, float value) {
         tags[name] = (new FloatTag(name, value));
     }
 
-    void putDouble(const wchar_t* name, double value) {
+    void putDouble(const std::wstring& name, double value) {
         tags[name] = (new DoubleTag(name, value));
     }
 
-    void putString(const wchar_t* name, const std::wstring& value) {
+    void putString(const std::wstring& name, const std::wstring& value) {
         tags[name] = (new StringTag(name, value));
     }
 
-    void putByteArray(const wchar_t* name, byteArray value) {
+    void putByteArray(const std::wstring& name, byteArray value) {
         tags[name] = (new ByteArrayTag(name, value));
     }
 
-    void putIntArray(const wchar_t* name, intArray value) {
+    void putIntArray(const std::wstring& name, intArray value) {
         tags[name] = (new IntArrayTag(name, value));
     }
 
-    void putCompound(const wchar_t* name, CompoundTag* value) {
+    void putCompound(const std::wstring& name, CompoundTag* value) {
         tags[name] = value->setName(std::wstring(name));
     }
 
-    void putBoolean(const wchar_t* string, bool val) {
-        putByte(string,
-                val ? static_cast<uint8_t>(1) : static_cast<uint8_t>(0));
+    void putBoolean(const std::wstring& name, bool val) {
+        putByte(name, val ? (uint8_t)1 : 0);
     }
 
-    Tag* get(const wchar_t* name) {
+    Tag* get(const std::wstring& name) {
         AUTO_VAR(it, tags.find(name));
         if (it != tags.end()) return it->second;
         return NULL;
     }
 
-    bool contains(const wchar_t* name) { return tags.find(name) != tags.end(); }
+    bool contains(const std::wstring& name) {
+        return tags.find(name) != tags.end();
+    }
 
-    uint8_t getByte(const wchar_t* name) {
+    uint8_t getByte(const std::wstring& name) {
         if (tags.find(name) == tags.end()) return (uint8_t)0;
         return ((ByteTag*)tags[name])->data;
     }
 
-    short getShort(const wchar_t* name) {
+    short getShort(const std::wstring& name) {
         if (tags.find(name) == tags.end()) return (short)0;
         return ((ShortTag*)tags[name])->data;
     }
 
-    int getInt(const wchar_t* name) {
+    int getInt(const std::wstring& name) {
         if (tags.find(name) == tags.end()) return (int)0;
         return ((IntTag*)tags[name])->data;
     }
 
-    int64_t getLong(const wchar_t* name) {
+    int64_t getLong(const std::wstring& name) {
         if (tags.find(name) == tags.end()) return (int64_t)0;
         return ((LongTag*)tags[name])->data;
     }
 
-    float getFloat(const wchar_t* name) {
+    float getFloat(const std::wstring& name) {
         if (tags.find(name) == tags.end()) return (float)0;
         return ((FloatTag*)tags[name])->data;
     }
 
-    double getDouble(const wchar_t* name) {
+    double getDouble(const std::wstring& name) {
         if (tags.find(name) == tags.end()) return (double)0;
         return ((DoubleTag*)tags[name])->data;
     }
 
-    std::wstring getString(const wchar_t* name) {
+    std::wstring getString(const std::wstring& name) {
         if (tags.find(name) == tags.end()) return std::wstring(L"");
         return ((StringTag*)tags[name])->data;
     }
 
-    byteArray getByteArray(const wchar_t* name) {
+    byteArray getByteArray(const std::wstring& name) {
         if (tags.find(name) == tags.end()) return byteArray();
         return ((ByteArrayTag*)tags[name])->data;
     }
 
-    intArray getIntArray(const wchar_t* name) {
-        if (tags.find(name) == tags.end()) return intArray(0);
+    intArray getIntArray(const std::wstring& name) {
+        if (tags.find(name) == tags.end()) return intArray();
         return ((IntArrayTag*)tags[name])->data;
     }
 
-    CompoundTag* getCompound(const wchar_t* name) {
+    CompoundTag* getCompound(const std::wstring& name) {
         if (tags.find(name) == tags.end()) return new CompoundTag(name);
         return (CompoundTag*)tags[name];
     }
 
-    ListTag<Tag>* getList(const wchar_t* name) {
-        // 4jcraft changed this function to not do a c style cast
-        // of a templated class
-        auto it = tags.find(name);
-        if (it == tags.end()) return new ListTag<Tag>(name);
-        return dynamic_cast<ListTag<Tag>*>(it->second);
+    ListTag<Tag>* getList(const std::wstring& name) {
+        if (tags.find(name) == tags.end()) return new ListTag<Tag>(name);
+        return (ListTag<Tag>*)tags[name];
     }
 
-    bool getBoolean(const wchar_t* string) {
-        return getByte(string) != static_cast<uint8_t>(0);
+    bool getBoolean(const std::wstring& std::string) {
+        return getByte(std::string) != 0;
     }
 
     void remove(const std::wstring& name) {
@@ -186,21 +192,21 @@ public:
 
     void print(char* prefix, std::ostream out) {
         /*
-Tag::print(prefix, out);
-        out << prefix << "{" << std::endl;
+        Tag::print(prefix, out);
+        out << prefix << "{" << endl;
 
         char *newPrefix = new char[ strlen(prefix) + 4 ];
         strcpy( newPrefix, prefix);
         strcat( newPrefix, "   ");
 
         AUTO_VAR(itEnd, tags.end());
-        for( std::unordered_map<string, Tag *>::iterator it = tags.begin(); it
-!= itEnd; it++ )
+        for( unordered_map<string, Tag *>::iterator it = tags.begin(); it !=
+        itEnd; it++ )
         {
-                it->second->print(newPrefix, out);
+        it->second->print(newPrefix, out);
         }
         delete[] newPrefix;
-        out << prefix << "}" << std::endl;
+        out << prefix << "}" << endl;
         */
     }
 
diff --git a/Minecraft.World/IO/NBT/DoubleTag.h b/Minecraft.World/IO/NBT/DoubleTag.h
index 5df0e1bb6..319c9bb33 100644
--- a/Minecraft.World/IO/NBT/DoubleTag.h
+++ b/Minecraft.World/IO/NBT/DoubleTag.h
@@ -11,7 +11,7 @@ public:
     }
 
     void write(DataOutput* dos) { dos->writeDouble(data); }
-    void load(DataInput* dis) { data = dis->readDouble(); }
+    void load(DataInput* dis, int tagDepth) { data = dis->readDouble(); }
 
     uint8_t getId() { return TAG_Double; }
     std::wstring toString() {
diff --git a/Minecraft.World/IO/NBT/EndTag.h b/Minecraft.World/IO/NBT/EndTag.h
index 33ee95469..94b87c7e6 100644
--- a/Minecraft.World/IO/NBT/EndTag.h
+++ b/Minecraft.World/IO/NBT/EndTag.h
@@ -6,7 +6,7 @@ public:
     EndTag() : Tag(L"") {}
     EndTag(const std::wstring& name) : Tag(name) {}
 
-    void load(DataInput* dis) {};
+    void load(DataInput* dis, int tagDepth) {};
     void write(DataOutput* dos) {};
 
     uint8_t getId() { return TAG_End; }
diff --git a/Minecraft.World/IO/NBT/FloatTag.h b/Minecraft.World/IO/NBT/FloatTag.h
index a61d2c54b..7651d761c 100644
--- a/Minecraft.World/IO/NBT/FloatTag.h
+++ b/Minecraft.World/IO/NBT/FloatTag.h
@@ -11,7 +11,7 @@ public:
     }
 
     void write(DataOutput* dos) { dos->writeFloat(data); }
-    void load(DataInput* dis) { data = dis->readFloat(); }
+    void load(DataInput* dis, int tagDepth) { data = dis->readFloat(); }
 
     uint8_t getId() { return TAG_Float; }
     std::wstring toString() {
diff --git a/Minecraft.World/IO/NBT/IntArrayTag.h b/Minecraft.World/IO/NBT/IntArrayTag.h
index 7b3a9c22f..a95519b05 100644
--- a/Minecraft.World/IO/NBT/IntArrayTag.h
+++ b/Minecraft.World/IO/NBT/IntArrayTag.h
@@ -7,12 +7,14 @@ class IntArrayTag : public Tag {
 public:
     intArray data;
 
-    IntArrayTag(const std::wstring& name) : Tag(name) {}
+    IntArrayTag(const std::wstring& name) : Tag(name) { data = intArray(); }
 
     IntArrayTag(const std::wstring& name, intArray data) : Tag(name) {
         this->data = data;
     }
 
+    ~IntArrayTag() { delete[] data.data; }
+
     void write(DataOutput* dos) {
         dos->writeInt(data.length);
         for (unsigned int i = 0; i < data.length; i++) {
@@ -20,7 +22,7 @@ public:
         }
     }
 
-    void load(DataInput* dis) {
+    void load(DataInput* dis, int tagDepth) {
         int length = dis->readInt();
 
         if (data.data) delete[] data.data;
diff --git a/Minecraft.World/IO/NBT/IntTag.h b/Minecraft.World/IO/NBT/IntTag.h
index 3ec50cf8c..5da7fb233 100644
--- a/Minecraft.World/IO/NBT/IntTag.h
+++ b/Minecraft.World/IO/NBT/IntTag.h
@@ -10,7 +10,7 @@ public:
     }
 
     void write(DataOutput* dos) { dos->writeInt(data); }
-    void load(DataInput* dis) { data = dis->readInt(); }
+    void load(DataInput* dis, int tagDepth) { data = dis->readInt(); }
 
     uint8_t getId() { return TAG_Int; }
     std::wstring toString() {
diff --git a/Minecraft.World/IO/NBT/ListTag.h b/Minecraft.World/IO/NBT/ListTag.h
index 133c59c61..c112795cd 100644
--- a/Minecraft.World/IO/NBT/ListTag.h
+++ b/Minecraft.World/IO/NBT/ListTag.h
@@ -1,5 +1,4 @@
 #pragma once
-
 #include "Tag.h"
 
 template <class T>
@@ -25,14 +24,22 @@ public:
         for (AUTO_VAR(it, list.begin()); it != itEnd; it++) (*it)->write(dos);
     }
 
-    void load(DataInput* dis) {
+    void load(DataInput* dis, int tagDepth) {
+        if (tagDepth > MAX_DEPTH) {
+#ifndef _CONTENT_PACKAGE
+            printf("Tried to read NBT tag with too high complexity, depth > %d",
+                   MAX_DEPTH);
+            __debugbreak();
+#endif
+            return;
+        }
         type = dis->readByte();
         int size = dis->readInt();
 
         list.clear();
         for (int i = 0; i < size; i++) {
             Tag* tag = Tag::newTag(type, L"");
-            tag->load(dis);
+            tag->load(dis, tagDepth);
             list.push_back(tag);
         }
     }
@@ -55,9 +62,8 @@ public:
         strcpy(newPrefix, prefix);
         strcat(newPrefix, "   ");
         AUTO_VAR(itEnd, list.end());
-        for (AUTO_VAR(it, list.begin()); it != itEnd; it++) {
+        for (AUTO_VAR(it, list.begin()); it != itEnd; it++)
             (*it)->print(newPrefix, out);
-        }
         delete[] newPrefix;
         out << prefix << "}" << std::endl;
     }
@@ -65,7 +71,10 @@ public:
     void add(T* tag) {
         type = tag->getId();
         // 4J: List tag write/load doesn't preserve tag names so remove them so
-        // we can safely do comparisons. This is the least invasive fix.
+        // we can safely do comparisons There are a few ways I could have fixed
+        // this but this seems the least invasive, most complete fix (covers
+        // other items that also use list tags and require equality checks to
+        // work) considering we can't change the write/load functions.
         tag->setName(L"");
         list.push_back(tag);
     }
@@ -100,8 +109,9 @@ public:
                 if (list.size() == o->list.size()) {
                     equal = true;
                     AUTO_VAR(itEnd, list.end());
-                    // 4J Stu - Pretty inefficient method, but acceptable for
-                    // how small and infrequent these comparisons are.
+                    // 4J Stu - Pretty inefficient method, but I think we can
+                    // live with it give how often it will happen, and the small
+                    // sizes of the data sets
                     for (AUTO_VAR(it, list.begin()); it != itEnd; ++it) {
                         bool thisMatches = false;
                         for (AUTO_VAR(it2, o->list.begin());
diff --git a/Minecraft.World/IO/NBT/LongTag.h b/Minecraft.World/IO/NBT/LongTag.h
index 810e52946..5e8018669 100644
--- a/Minecraft.World/IO/NBT/LongTag.h
+++ b/Minecraft.World/IO/NBT/LongTag.h
@@ -10,7 +10,7 @@ public:
     }
 
     void write(DataOutput* dos) { dos->writeLong(data); }
-    void load(DataInput* dis) { data = dis->readLong(); }
+    void load(DataInput* dis, int tagDepth) { data = dis->readLong(); }
 
     uint8_t getId() { return TAG_Long; }
     std::wstring toString() {
diff --git a/Minecraft.World/IO/NBT/ShortTag.h b/Minecraft.World/IO/NBT/ShortTag.h
index be04c8c57..e47b99341 100644
--- a/Minecraft.World/IO/NBT/ShortTag.h
+++ b/Minecraft.World/IO/NBT/ShortTag.h
@@ -10,7 +10,7 @@ public:
     }
 
     void write(DataOutput* dos) { dos->writeShort(data); }
-    void load(DataInput* dis) { data = dis->readShort(); }
+    void load(DataInput* dis, int tagDepth) { data = dis->readShort(); }
 
     uint8_t getId() { return TAG_Short; }
     std::wstring toString() {
diff --git a/Minecraft.World/IO/NBT/StringTag.h b/Minecraft.World/IO/NBT/StringTag.h
index bf5c2dcc9..a7b72eee3 100644
--- a/Minecraft.World/IO/NBT/StringTag.h
+++ b/Minecraft.World/IO/NBT/StringTag.h
@@ -11,7 +11,7 @@ public:
 
     void write(DataOutput* dos) { dos->writeUTF(data); }
 
-    void load(DataInput* dis) { data = dis->readUTF(); }
+    void load(DataInput* dis, int tagDepth) { data = dis->readUTF(); }
 
     uint8_t getId() { return TAG_String; }
 
diff --git a/Minecraft.World/IO/NBT/Tag.cpp b/Minecraft.World/IO/NBT/Tag.cpp
index 9e157eef7..74bc4a802 100644
--- a/Minecraft.World/IO/NBT/Tag.cpp
+++ b/Minecraft.World/IO/NBT/Tag.cpp
@@ -61,7 +61,9 @@ Tag* Tag::setName(const std::wstring& name) {
     return this;
 }
 
-Tag* Tag::readNamedTag(DataInput* dis) {
+Tag* Tag::readNamedTag(DataInput* dis) { return readNamedTag(dis, 0); }
+
+Tag* Tag::readNamedTag(DataInput* dis, int tagDepth) {
     uint8_t type = dis->readByte();
     if (static_cast<int>(type) == 0) return new EndTag();
 
@@ -82,7 +84,7 @@ Tag* Tag::readNamedTag(DataInput* dis) {
     //        byte[] bytes = new uint8_t[length];
     //        dis.readFully(bytes);
 
-    tag->load(dis);
+    tag->load(dis, tagDepth);
     return tag;
 }
 
@@ -156,4 +158,4 @@ const wchar_t* Tag::getTagName(uint8_t type) {
             return L"TAG_Compound";
     }
     return L"UNKNOWN";
-}
+}
\ No newline at end of file
diff --git a/Minecraft.World/IO/NBT/Tag.h b/Minecraft.World/IO/NBT/Tag.h
index 68adeeda2..c80209d72 100644
--- a/Minecraft.World/IO/NBT/Tag.h
+++ b/Minecraft.World/IO/NBT/Tag.h
@@ -16,6 +16,7 @@ public:
     static const uint8_t TAG_List = static_cast<uint8_t>(9);
     static const uint8_t TAG_Compound = static_cast<uint8_t>(10);
     static const uint8_t TAG_Int_Array = static_cast<uint8_t>(11);
+    static const int MAX_DEPTH = static_cast<uint8_t>(512);
 
 private:
     std::wstring name;
@@ -25,7 +26,7 @@ protected:
 
 public:
     virtual void write(DataOutput* dos) = 0;
-    virtual void load(DataInput* dis) = 0;
+    virtual void load(DataInput* dis, int tagDepth) = 0;
     virtual std::wstring toString() = 0;
     virtual uint8_t getId() = 0;
     void print(std::ostream out);
@@ -33,6 +34,7 @@ public:
     std::wstring getName();
     Tag* setName(const std::wstring& name);
     static Tag* readNamedTag(DataInput* dis);
+    static Tag* readNamedTag(DataInput* dis, int tagDepth);
     static void writeNamedTag(Tag* tag, DataOutput* dos);
     static Tag* newTag(uint8_t type, const std::wstring& name);
     static const wchar_t* getTagName(uint8_t type);