Monday, July 09, 2007

There is much to be said about the folklore surrounding Julian Gollop's Chaos. Despite being released over 20 years ago, people were still discovering new "features" up until a few years ago.

These features are partly due to classic eater-egg game design, partly due to what seems to be "copy-paste coding" and partly due to external factors. Either way, they add to the mystery and magic of the game whether intentional or not.

The Turmoil spell, which can only be gained by camping in a Magic Wood and only then does it randomly appear once in a blue moon, is an example of one easter egg that can be enjoyed by persistent gamers.

The many owner-changing routes or status-changing tricks are examples of copy-paste coding. The code that manipulates the flags that tell the game what properties a creature has (is it undead? which wizard does it belong to?) are duplicated whenever they are needed in the game - for example when a Gooey Blob recedes or when a lightning bolt blasts a creature to smithereens. Sometimes not all of the flag manipulating steps have been copied correctly, bugs fixed in one place are still present in another.

One manifestation of this is the classic trick to create a real Golden Dragon. Move the illusionary creature towards a Gooey Blob. Wait for the inevitable cover up. Free the creature by killing the blob. Ta-da! Now the creature is real... This kind of trick separates the Gandalfs from the Grot Bags.

The external factors that lead to the other Chaos myths are common in modern video games: the looming deadline. After picking through the code of Chaos with a fine tooth-comb, one can see that it has several half-finished ideas that are not present in the final game. Spells that never appear, checks for status that never occur and graphics that are not used. There's plenty of memory left, so the most likely reason for these missing features is that the publisher wanted the game out of the door.

The most complete missing spell is the Troll - a fairly mundane creature with no special features. Other spells exist as little more than their names: Blind, Tempest, Teleport, Dead Revenge, Consecration, Dispel, Counter Spell, and Magic Sleep. There's even a sleeping Gooey Blob in there!

Now a keen hacker on the Gooey Blob mailing list has implemented all of these missing spells, plus a few more, in a modified version of the game. Quite an achievement - at last count he had just 30 spare bytes. The next logical step was for me to add them to my Chaos remake. The first few are now in place - Blind and Magic Sleep have been added to the version in subversion.