diff --git a/ArcFormats/AdvScripter/ArcPAK.cs b/ArcFormats/AdvScripter/ArcPAK.cs
new file mode 100644
index 00000000..1b64fed9
--- /dev/null
+++ b/ArcFormats/AdvScripter/ArcPAK.cs
@@ -0,0 +1,166 @@
+//! \file       ArcPAK.cs
+//! \date       2018 Jan 31
+//! \brief      ADVScripter resource archive.
+//
+// Copyright (C) 2018 by morkt
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//
+
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.Composition;
+using System.IO;
+using GameRes.Compression;
+using GameRes.Utility;
+
+namespace GameRes.Formats.AdvScripter
+{
+    internal class MdArchive : ArcFile
+    {
+        public readonly int Version;
+
+        public MdArchive (ArcView arc, ArchiveFormat impl, ICollection<Entry> dir, int version)
+            : base (arc, impl, dir)
+        {
+            Version = version;
+        }
+    }
+
+    [Export(typeof(ArchiveFormat))]
+    public class PakOpener : ArchiveFormat
+    {
+        public override string         Tag { get { return "PAK/MD002"; } }
+        public override string Description { get { return "ADVScripter engine resource archive"; } }
+        public override uint     Signature { get { return 0x3030444D; } } // 'MD002'
+        public override bool  IsHierarchic { get { return false; } }
+        public override bool      CanWrite { get { return false; } }
+
+        public override ArcFile TryOpen (ArcView file)
+        {
+            if (file.View.ReadByte (4) != '2' || !file.View.AsciiEqual (0x21, "00V"))
+                return null;
+            int count = file.View.ReadInt32 (0x24);
+            if (!IsSaneCount (count))
+                return null;
+            int version = file.View.ReadByte (0x20) - '0';
+            if (version < 1 || version > 9)
+                return null;
+            var index_entry = new IndexReader (file, version);
+            var buffer = new byte[0x30];
+            uint index_offset = 0x28;
+            var dir = new List<Entry> (count);
+            for (int i = 0; i < count; ++i)
+            {
+                file.View.Read (index_offset, buffer, 0, 0x30);
+                index_entry.Decrypt (buffer);
+                var name = Binary.GetCString (buffer, 0, 0x20);
+                var entry = FormatCatalog.Instance.Create<PackedEntry> (name);
+                entry.Offset       = index_entry.Offset;
+                entry.UnpackedSize = index_entry.UnpackedSize;
+                entry.Size         = index_entry.PackedSize;
+                entry.IsPacked     = buffer.ToInt32 (0x20) != 0;
+                if (!entry.CheckPlacement (file.MaxOffset))
+                    return null;
+                dir.Add (entry);
+                index_offset += 0x30;
+            }
+            return new MdArchive (file, this, dir, version);
+        }
+
+        public override Stream OpenEntry (ArcFile arc, Entry entry)
+        {
+            var mdarc = arc as MdArchive;
+            Stream input = arc.File.CreateStream (entry.Offset, entry.Size);
+            if (mdarc != null && (mdarc.Version >= 5 && mdarc.Version <= 8))
+                input = new XoredStream (input, 0xFF);
+            var pent = entry as PackedEntry;
+            if (pent != null && pent.IsPacked)
+                input = new LzssStream (input);
+            return input;
+        }
+
+        internal class IndexReader
+        {
+            public uint Offset;
+            public uint PackedSize;
+            public uint UnpackedSize;
+
+            public readonly Action<byte[]> Decrypt;
+
+            private uint m_key;
+
+            public IndexReader (ArcView file, int version)
+            {
+                if (1 == version || 5 == version)
+                {
+                    Decrypt = buffer => {
+                        Offset       = buffer.ToUInt32 (0x24);
+                        UnpackedSize = buffer.ToUInt32 (0x28);
+                        PackedSize   = buffer.ToUInt32 (0x2C);
+                    };
+                    return;
+                }
+                else if (2 == version || 6 == version)
+                    m_key = uint.MaxValue;
+                else
+                    m_key = file.View.ReadUInt32 (0x1C);
+
+                Action<byte[]> read = buffer => {
+                    Offset       = buffer.ToUInt32 (0x24) ^ m_key;
+                    UnpackedSize = buffer.ToUInt32 (0x28) ^ m_key;
+                    PackedSize   = buffer.ToUInt32 (0x2C) ^ m_key;
+                };
+                Action transform;
+                if (9 == version)
+                {
+                    transform = () => {
+                        Offset       = (Offset       & 0xFFFF) << 15 | Offset       >> 17;
+                        UnpackedSize = (UnpackedSize & 0xFFFF) << 14 | UnpackedSize >> 18;
+                        PackedSize   = (PackedSize   & 0xFFFF) << 13 | PackedSize   >> 19;
+                    };
+                }
+                else
+                {
+                    transform = () => {
+                        Offset       >>= 1;
+                        UnpackedSize >>= 2;
+                        PackedSize   >>= 3;
+                    };
+                }
+
+                Action<byte[]> decrypt_name = buffer => { };
+                if (9 == version || 4 == version || 8 == version)
+                {
+                    var key_bytes = new byte[4];
+                    LittleEndian.Pack (m_key, key_bytes, 0);
+                    decrypt_name = buffer => {
+                        for (int i = 0; i < 28; ++i)
+                            buffer[i] ^= key_bytes[i & 3];
+                    };
+                }
+                Decrypt = buffer => {
+                    read (buffer);
+                    transform ();
+                    decrypt_name (buffer);
+                };
+            }
+        }
+    }
+}