ToME Wiki
Adding new monsters in r info file
By CosmicGerbil
Adding new monsters for the complete newbie.
Here is an example monster to look at.
N:14:Agent of the black market G:t:b I:110:2d8:10:8:99 W:0:1:1200:0 E:1:1:1:2:1:1 O:25:50:20:5 B:HIT:HURT:1d6 B:TOUCH:EAT_ITEM B:INSULT:* F:MALE | DROP_CORPSE | DROP_SKELETON | F:DROP_60 | WILD_TOWN | F:WILD_SWAMP | WILD_WOOD | WILD_GRASS | WILD_MOUNTAIN | WILD_ONLY | F:TAKE_ITEM | OPEN_DOOR | BASH_DOOR | F:EVIL | MORTAL | BASEANGBAND | HAS_LITE D:He 'finds' new wares for the Black Market. From unwary adventurers...
What does it all mean?
N:14:Agent of the black market This is the monsters number in the monster index and also its name. Obvious really 
G:t:b. G stands for graphics, and this is the graphics line, which shows how the monster will look in the game. t is the monster symbol, meaning "townperson". Monsters are nearly always represented by letters of the alphabet. b is the colour of the monster, meaning blue. There are 16 colours available for monsters and they are:
D - Dark Gray w - White s - Gray o - Orange r - Red g - Green b - Blue u - Brown d - Black W - Light Gray v - Violet y - Yellow R - Light Red G - Light Green B - Light Blue U - Light Brown
Which colour you use for monsters usually follows a pattern, for example, warriors are usually coloured brown (u), while rogues are coloured blue (b). Of course, you can use any colour that you think is suitable. In Gerband, I colour my rangers "g", and in main T.o.M.E they are "W"
I:110:2d8:10:8:99
I stands for information. 110 is normal speed. The higher this number the faster the monster. 2d8 is the monsters hit points and means 2 dice with 8 sides are rolled to determine how many hit points the Agent of the black market has. So he could have anything from 2 to 16 hit points, depending on how the Random Number Generator has rolled his dice. 10 means vision in tens of feet. The Agent of the black market can see up to 100 feet. 8 means armour class. the higher this number, the better armour a monster has, and it will be harder to defeat. 99 means alertness. This goes backwards; a monster with 0 here, is always alert, while a monster with 255 (the highest number used here) will probably ignore you a lot.
W:0:1:1200:0
W stands for more information 0 is the depth level you will find a monster. 0 in this case stands for the surface. A 5 here means you would find this monster on dungeon level 5. 1 means rarity. 1 is the most common. As far as I know, this number can go up to infinity, although after a certain increase, the chance of a monster appearing would be so small, that such a high number would be next to useless. 1200 means corpse weight in deci-pounds. Quote from r.info file "19 deci-pounds seem to get added to these number in practice" 0 here means the number of experience points you get for killing a monster. Town monsters do not give experince.
E:1:1:1:2:1:1
E means equipment slots 1 is the weapon slots, the Agent of the black market can wield one weapon The next 1 is the torso slot (he has only one body to wear armour on:)) The third 1 is arm slots (expressed in number of pairs), The 2 means finger slots. Even though the Agent of the black market has 8 fingers and 2 thumbs (unless he lost some in battle 
, he can only wear two rings. According to the game rules, this is because magic rings only work when worn on the third finger. This applies to humanoids, but some monsters (such as a giant squid) can wear 6 rings. For some reason, the game will not let players or monsters wear any more than 6 rings, no matter how many fingers/tentacles they have This 1 means head slots (for helms) The final 1 means leg slots (expressed in number of pairs).
O:25:50:20:5
The O stands for object drop chance. The four following slots indicate what type of object a monster may drop when you kill it. The slots stand for treasure, combat items, magic items and tools. The numbers indicate the percentage likelihood of the type of object dropped. So if the Agent of the black market drops an object after death, he has 25% chance of dropping treasure, 50% chance of dropping combat items, 20% chance of dropping magic items and 5% chance of dropping tools. Some monsters, such as animals do not carry any objects and their object line would read O:0:0:0:0. Also sometimes the percentages don't always add up to 100%. If a monster has an object line like this O:20:50:20:5, then there is a 5% chance the monster will drop junk.
B:HIT:HURT:1d6 B:TOUCH:EAT_ITEM B:INSULT:*
The B lines stand for "blows" and they are attack lines. A monster can have a maximum of four B lines. There are *lots* of differnt types of attacks that monsters can use, and the best way to learn them all is to read through the r info file.
B:HIT:HURT:1d6 is obvious, it means that the Agent of the black market can do anything from 1 to 6 points of damage to you.
B:TOUCH:EAT_ITEM means that if the Agent of the black market touches you, he will try to steal an item from your inventory.
B:INSULT:* means that he insults you in a random number of ways 
F:MALE | DROP_CORPSE | DROP_SKELETON | F:DROP_60 | WILD_TOWN | F:WILD_SWAMP | WILD_WOOD | WILD_GRASS | WILD_MOUNTAIN | WILD_ONLY | F:TAKE_ITEM | OPEN_DOOR | BASH_DOOR | F:EVIL | MORTAL | BASEANGBAND | HAS_LITE
F stands for flags and they describe some other things about the monster and also other stuff he can do. Some of these are obvious, for example the Agent of the black market is always male, he's evil and mortal (some monsters,such as golems are immortal), when you kill him, he can leave behind a corpse or a skeleton, and 60% of the time, he will drop an object (see the O line for more info on this). Also the wild flags indicate where he can be found in the wilderness. WILD_TOWN means he is a town monster (and therefore won't give you any experince if you kill him). He can open and bash down doors, TAKE_ITEM means he picks up any items he finds on the floor. Also he is an original Angband monster (at least I think that's what BASEANGBAND means) and HAS_LITE means he will "light up" a small area of the town around him when it is dark!
Like the B lines, there are lots of Flags to learn. Once again, it is a good idea to read through r info to learn more about these.
D:He 'finds' new wares for the Black Market. From unwary adventurers
D means description, and when you examine a monster in the game by pressing "l" what is written in this D line will apper in the monster description in the game.
One line that has not been featured here is the spells line. These lines always come after the F lines and before the D lines. They look like this:
F:MORTAL | BASEANGBAND | HAS_LITE S:1_IN_6 | S:BLINK | BLIND | CONF | MISSILE D:He is leaving behind a trail of dropped spell components.
This is part of a novice wizard description from Gerband.
S:1_IN_6 | means that the wizard will cast a spell once in every six turns he takes. S:1_IN_1 |would mean that a monster wouls neve move just cast spells. S:1_IN_0 | can not be used as it crashes the game.
S:BLINK | BLIND | CONF | MISSILE. These are some of the spells that the novice wizard can cast. There are lots more spells in T.o.M.E. BLINK means the wizard blinks (teleports) away. The other three spells are attack spells he may use on you!
To actually add in a new monster you can either delete an existing monster and put your new monster in the empty slot, or you can add a new monster after the main list. This list goes up to 1076 in T.o.M.E, so the new monster would have to have a monster number of 1077. If you do the second option, you must tell the game that the maximum number of monsters allowed has increased. To do this, go into lib/edit and open the misc file. You will find this:
# Maximum number of monsters in r_info.txt # WARNING ! add one more to the real count for the player ghost !! M:R:1078
Alter the 1078 to 1079. For every new monster you add on to the end of the r info file, increase the above number by 1 each time.
Even though there are only 1076 monsters and the number reads 1078, this is because (as the second line with the # in front of it explains) the player ghost is included. The other extra number is for the player, who is always monster number 0.