ToME WikiOkay - just a few thoughts on how to build in some of that old-school Call of Cthulu feel.
- A "Language Theory" skill, with subskills of "Ancient" and "Modern", each of which would have further subskills. Figure four ancient languages, and four Modern. All of these would be relatively cheap. All characters would start with full fluency in their native tongue. The "Language Theory" skills would function a bit like Geomancy - useless in and of themselves, but putting a point into either Ancient or Modern would put .7 points in each of their subskills, and putting one point in general language theory would put .5 in all languages.
- The character would start out with a large stack of initial skill points to spend, but wouldn't get them very quickly at all thereafter.
- Books have a language requirement - a specific language and a skill level in it. If your appropriate Language skill is high enough, you can read it flat out. This takes a while, and is best done in a library. If your appropriate Language skill is at least half that necessary, and you are in a library, you can Translate it. This takes even longer. If you at least have a point of the language skill, you can tell what language it is, and with a bit more you can tell the title and language skill required.
- some books will provide useful information. This can come in the form of entries in the monster memory, items on the "identified" list, quests, clues, or even improvements to certain skills. There really is no way to determine what a book holds without reading it and suffering its effects. Effects can include loss of SAN and improvements to certain skills.
- Time is important. As time passes, things happen, and the events continually grow more dangerous. NPC uniques can die. Monsters can infest certain areas. You can be attacked randomly. Eventually, if you do nothing, the cultists will summon Yog-Sothoth, and everyone will lose. Doing things to disrupt the cultists will, of course, push this timetable back.
- Clues can be gained through a variety of means - saying the right things to the right people, finding things through the search command, killing certain uniques, tripping certain events, completing certain qests, and so on. There is a "clue track" - as you become more clued, you will get helpful quests - like "search the old church after midnight" and "Tell the police chief about the planned bank heist". There is also a "cultist awareness" track. As you do obvious things to thwart the cultists, they'll figure out more about you, and the events will generally become more threatening.
- Monster memory will be important. In particular, the special vulnerabilities of various monsters will change from game to game. It also will not be persistent in the same way. Instead, the character will have the opportunity to buy a journal, and can (with a bit of time) write the items and monsters that he knows in it. After he dies, the characters that follow after him will receive his journal, thankfully written in their native tongue. A bit of time spent perusing it will give them those entries in both the item list and the monster memory. Monster weaknesses will be recorded as having been discovered or not, rather than specifics. If they were discovered, then the new character will know the special weakness of *his* version.
- There is such a thing as a telephone. It will be in the library. You will start game with a phonebook. Talkign to various people and reading certain texts will give you the phone numbers of various useful people. Some of them will require fluency in one of the modern languages before you can speak with them.
- Initially, the monsters you face will be relatively mundane - humans, in particular, with the occasional dog or some such. As the cultists get closer to their goal, however, and as you penetrate the mysteries further, you will begin to encounter less natural foes. The first time you encounter one of these creature types, you will lose SAN. You may also gain Cthulu Mythos skill. You can also lose SAN for witnessing a monster spell effect for the first time.
- Regaining SAN requires visits to the psychotherapist - it's time-consuming, and only available at certain hours of the day. It should be designed so that you'ld really rather not spend the time if you can at all avoid it. You do get a *bit* back from a good night's sleep, mind.
- You have an apartment, with a small library and a bed. Failure to sleep at night will catch up with you pretty quick.
- HPs represent fatigue. Some attacks will only do fatigue damage, especialy if you are a trained fighter. More lethal attacks, however, are represented by temporary ability damage. A good night's sleep can heal a little, but anything beyond that will require the hospital - and more time.
- You start with a Sanity skill of 50. Every point you gain in Cthulu Mythos is subtracted from your Sanity skill. Your SAN max substat is equal to your Sanity skill times your POWer stat. POW also influences luck and is important for spellcasting.
- Nobody starts with spellcasting. No one can buy it with skill points. Instead, there are a series of "path" skills, that function much like mindcraft or necromancy. Things like "Path of the Blood", "Path of the Forbidden Flesh" and so forth. Reading certain books (specifically, the ones that give you Cthulu Mythos and take SAN) can also give you skill in these path skills. The powers from the path skills do amazing things, but be wary. They cost SAN to cast, and sometimes POW (which cannot be healed by rest or he Hospital) as well. Spells cannot give you back SAN, but they can do almost anything else. (For an idea, if you find the final ritual place and time, and go there by yourself, but do not successfully disrupt it, default is that they summon Shub-Niggurath, the game ends, and everybody loses. If, however, you have 50 points in the "Path of Summonings and Compulsion" skill, the ability to use it, and at least 3 points of POW remaining, they summon Shub-Niggurath, you automatically cast the appropriate spell at the appropriate time, the game ends, and everybody *else* loses.)
- Insanities are tracked as corruptions. Every time you drop below a certain threshold of SAN, you get one. Bobbing back and forth across that threshold won't cure you, but it wont do you any further harm, either. Losing all of your SAN initially just turns you into a vegetable, but may eventually let you continue playing as an "evil" character, with different game goals. (like the aforementioned "Let them summon it, then take control of the thing" goal.)
- Essentially, there should be at least a few totally different ways to play. On the one side, you can play a big, strong bruiser, who wanders around the bad part of town, beating up anyone who looks like a cultist, and getting clues from having them attack him all the time - leading him to locations where he can find and beat up on *more* cultists, and, by so doing, do enough damage to them that it takes them a good long time to accumulate the stuf they need, by which point he's got the time and place of the final ritual, goes there and prevents it. On the other, you can play an inquisitive type who spends his time tracking down clues nonviolently, not tipping the cultists off to his existence at all, gets in good with the cops (and gives them the tips they need to capture and thwart the cultists as appropriate) and then descends on the final ritual with a full-fledged SWAT team in tow. Friendly SWAT teams make such things a great deal easier. On the third, you can play a studious type, who spends his time tracking down books of occult lore, and occasionally getting tips from the newspaper (as someone of the "reporter" profession, you can spend a bit of time to write a story. The more clues you've got for the story, the more money it's worth. This *also* can both provide setbacks to the cultists and let them know that you're out there.) Once you have the eldritch power that you need (and hopefully are not yet *too* insane) you can walk into the bad parts of town, identify a few cultists, drag the location of the final ritual from their currently-melting brains, and descend upon it with terrible magics. In the meantime, you've been thwarting the cultists by beating them up and taking their stuff (who do *you* think has the best tomes of forbidden lore?) and by stealing things before they could get them (How do you think they *got* them?)
- There are no races. The equivalent of classes would be professions, including such as "Professor" and "College Student" (both of whom are strong in the academics and can access the Restricted Stacks of Miskatonic from the beginning of game. The Professor is focused on academic skills to the exclusion of all else, while the student has access to a *few* of the more physical arts). There would be both "Beat Cop" and "Police Detective" - both would have some investigative skills, some combat skills, and will find it significantly easier to call for police backup. The Beat Cop is more focused on the combat skills, while the detective is more focused on investigative, and has a bit of space for modern languages if he really wants to go that way. So on and so forth.
Just a few thoughts I put together - mostly inspired by the realization that a Cthulu-themed TOME would *have* to be named Necronomicon.
NerdanelVampire: Interesting! Someone should make this module! It won't be me though, as I already have mine.
BucketMan: Agreed. I'd love to see a Cthulu themed module. Especially now that we can have creepy ambient music in the background.
Mpolo: Maybe when you sleep you have the option to visit Dreamlands, where a completely separate parallel plot is going on...
AstroCreep: the only Lovecraft themed *band I know of is Cthangband, but the new maintainer has changed some names around to be more Tolkien-ish(some spirits if i remember right),which turned me off. are there any Lovecraft modules in the making? if not, any pointers on how i could try to make one?
BucketMan: Nerdanel's Zothiqband has some Cthulu references, but it's mostly based on works by Clark Ashton Smith, not Lovecraft. As to pointers...if you're new to module-making, my advice would be to first play with some of the existing modules to get some ideas about what's being done already. In particular take a look at Zombie Horror and Bone to Be Wild. They're both fairly simple, but have a good 'horror genre' ambiance that would be good influences for a Cthulu module, which should really be more than a bit scary. Once you have some ideas, start tinkering with the engine. To start with you'll probably just be making minor changes to get a feel for things, but several modules have gone way beyond this sort, and there's no need to feel limited to only changing skills, monsters and maps if you want to do more. Finally, don't be in a hurry. It may take a few months just to learn the engine. Building a module isn't something that's likely to be done in just a couple weekends.
NerdanelVampire: I agree about the above. Anyway, I'd love to get more module developers. It's been a bit dead here lately. Yes, I know it's partially my fault and I should look into developing Zothiqband further or try to figure out how to implement the (surprisingly complicated, as it turns out) background color capability in the engine because I really want it for Zothiqband to the point that it distracts me from doing other improvements...
EtMarc: Have you checked Steamband? It's 19th century themed, so it has (to my memory) some Lovecraft elements. At the least, the magic system is very close to it. As for the lack of module development, I should have the next version of BOB ready within a week. (hopefully)
NerdanelVampire: All this talk of modules has spurred me again. 
I just wrote a quick converter so that the next release of Zothiqband will now have ALL the vaults from ToME 2 making things more interesting (save for princess vaults, as random quests don't exist yet).