The game simply loads all *.txt files located inside the [mods] subfolder. The names of the files are not relevant and only used to group similar topics together.
The file format is fairly straightforward and self-explanatory, but to remove any confusion, let me explain it on a monster example that is also included in the release, The Fly. It has a separate file, [thefly.txt], and a picture, [thefly.png].
A fly is changeling, hunter monster, predator monster.
"-2, 2, 2, -3, 3, -4" is fly's stats.
"thefly" is fly's icon.
"scholarship" is fly's past.
"chitinous, nightmarish, cunning" is fly's abilities.
"overpowering, fast, tough" is fly's mutations.
"stung" is fly's kill.
"liquified, putrified, necrified, eaten" is fly's blast.
"1000" is fly's difficulty.
A fly is ...
This line defines the monster. Every monster has one required basic type and any number of additional types.
The basic types are:
- phantom: some dead people return as phantoms. All phantoms are listed in [ghosts.txt].
- zombie: some dead people return as zombies. All zombies are listed in [zombies.txt].
- vermin: monsters that come in swarms. They are listed in [vermin.txt] and elsewhere.
- inhuman: the most basic type of monster without specific attributes.
- inhumanoid: a sentient or intelligent sort of inhuman
- changeling: a monster that pretends to be a human, the serial killer of the game
- psycho killer: a "normal" human changeling/serial killer.
- body snatcher: a changeling that steals a human's body and uses it as host.
To learn more about the additional types, study the monsters already included with the game.
"willpower mod, sanity damage, health points, combat mod, damage, stealth mod"
Icon, Difficulty, Past
Icon tells the filename of the image used for the monster. You can use one of those included in the game or add a new one. Only [*.png] files are supported.
A simple way to create images like the ones used in the game is to export a grayscale as [*.gif] in MS Paint. Ignore the alert about color loss, that's exactly what we want to achieve. Don't forget to save again as [*.png].
Difficulty is the minimum difficulty level the monster is allowed to appear at. "0" or none specified defines Easy, "1" Medium, "2" Hard. Anything higher won't get used at all. This is how The Fly is disabled from the actual game (the difficulty is set to 1000).
The past defines possible past connections of the monster. They are mostly self explanatory and to see how they can be used, study the monsters already included with the game.
Abilities list all the abilities a monster always has. Mutations are picked at random depending on the power of specific "incarnation" of the monster. The abilities are also mostly self explanatory and can all be found in existing monsters.
Kill, Maim, Blast
These are the variations on how the particular monster kills, potentially maims or even obliterates its victim. The list of options is large and the number of possible combinations even larger, but all the options can be found in [*.txt] files included with the game, also many combinations to start from.
How to start?
My advice would be to copy one of the existing monsters, one closest to the monster you are trying to create, and start from there.
In its current stage, the game will crash if it cannot find enough monsters to fill everything up. This may happen if you disable too many of the monsters included, because it is programmed for monsters not to repeat within the single game.
That's all for now, have fun and cheers!