SCUMM

What is SCUMM?

SCUMM stands for "Script Creation Utility for Maniac Mansion".

It is a utility used to create the famous LucasArts adventure games like the Monkey Island series and also gave ScummVM its name.

The SCUMM language is a LucasArts in-house standard, but was also used by numerous Humongous Entertainment games. The format was never designed to be public and so would change unpredictably from game to game to suit the task at hand. Therefore, many different SCUMM Versions exist today.

It was initially created in 1987 by Aric Wilmunder and Ron Gilbert for the game Maniac Mansion and was used later, with some modifications, for Zak McKracken and the Alien Mindbenders.

Aric Wilmunder and Ron Gilbert's original SCUMM has been expanded a bit since 1988, of course. Every time a game required some feature that SCUMM had not previously supported, the interpreter was extended and the data file format expanded. The whole system was redesigned from scratch twice. With Indiana Jones and the Last Crusade, LucasArts developed a modular file format based loosely on the standard IFF format. This was used several times in various forms until The Secret of Monkey Island, where the SCUMM engine and file format was redesigned from scratch again. The new format was used from then on, and even now that LucasArts has finally retired SCUMM for their latest games, the interpreter/data file philosophy is still in use and you can see SCUMM design decisions in the data files of the latest LucasArts games such as Grim Fandango.

The idea behind SCUMM

It is well known that the best way to perform some very complex tasks is to start out by building a tool to help you with that task. In the same way, two programmers at LucasArts back in 1988 decided that rather than write a single, complicated program for their new graphic adventure game, they should instead build an generic engine that would play any graphic adventure game, if given the proper data files; this would let them concentrate on the game design, rather than the details of the programming.

It worked. And so SCUMM was born.

The way the SCUMM engine works is that there is a single executable program, called the interpreter, that operates on some data files. The data files contain images, dialogue, details of object behaviour, and so on. The interpreter then brings all this to life and handles the details of drawing it all, animating the characters, processing user input, and all the other details that a graphic adventure game needs dealt with in order to work properly. Because the data files contain no executable code, it turns out to be trivial to port the game to a new platform: just port the interpreter, and use the same data files. You will get exactly the same game on the new system.

A lesson many people have learnt. Infocom, creators of possibly the finest text adventure games of all time, did a very similar trick with their Z-machine; you can now get Z-machine interpreters for everything from a Cray Supercomputer to a Game Boy, all of which will play Infocom's games, encoded in the data files. See Brass Lantern for more information.

Sub Engines of SCUMM

The SCUMM virtual machine is made up of a number of sub engines working together. Strictly, the term SCUMM only refers to the scripting language itself. The official term for the virtual machine as a whole is SPUTM --- but getting people to change is probably a lost cause.

Here are all the engines used by the SCUMM virtual machine.

SPUTM: The 'real' name for the engine.
SCUMM: The actual scripting language.
IMUSE: The MIDI control system, allowing dynamic music.
SMUSH: A movie compression format and player.
INSANE: The event management system used in V7+ games.
MMUCAS: The memory allocation system used in The Curse of Monkey Island. V8 only.

Which games use SCUMM?

LucasArts games

and numerous Humongous Entertainment games.

Resources

SCUMM Technical Reference: Information about all aspects of SCUMM/SPUTM, including resource formats, opcode tables and many more things.
SCUMM Versions: A list of SCUMM versions, and which games they were used for.
SCUMM Debug Codes: Many of the original SCUMM game engines contain debug keys. This page lists known debug keys and the passwords needed to unlock them.
SCUMM NES: Progress of the support for the NES version of Maniac Mansion
SCUMM C64: Progress of the support for the C64 versions Maniac Mansion and Zak McKracken
Auto detection: Some thoughts on improving the SCUMM auto detector
HE Progress: Progress of the support for Humongous Entertainment games
HE Games List: List of all known HE games. Both supported and unsupported