LPD (Lua Program Data)

LPD files are what store the games LUA logic.

• Location: $GAMEDIR/client/script
• Extensions: lpd

The LPD file header is a simple struct which follows the following format:

struct header_t = {
  char file_type[4]; // Always "RLE\f"
  uint32 version; // Always 1
  uint32 file_size; // Unencrypted file size
  char padding;
}

The LPD file format is fairly straight forward it contains a basic file header follow the above format, then followed by the compiled lua script.

struct lpd_t = {
  header_t header;
  char script[];
}

The script is an “encrypted” form of the lua byte-code. The script can be decrypted using the following algorithm:

  char decoded = encoded ^ 0x73

File names are formatted as the following:

Normal Script: <script_name>.<le|be>.lpd
Program Script: <script_name>_p.<le|be>.lpd

Note: LE means Little Endian and BE means Big Endian

A script is a script that can be required by a Program Script.

A program script is what the client loads to handle the actual game logic for the lua script. In the client it converts the _p to .p on file load.

All file names in the scripts folder are encrypted, I haven’t found the actual algorithm used, to encrypte them. But I did discover that it is a basic substitution cipher, with the following key:

Note: This doesn’t map all possible characters only the ones that I have observed to be used by the game.

Character | Substituted Character
0 | j
1 | i
2 | h
a | 9
b | 8
c | 7
d | 6
e | 5
f | 4
g | 3
h | 2
i | 1
j | 0
k | z
l | y
m | x
n | w
o | v
p | u
q | t
r | s
s | r
t | q
u | p
v | o
w | n
y | l
z | k

• All LUA files are using LUA 5.1 and can be recovered using something like LuaDec.
• All Lua scripts are compiled using Little Endian.