House rule mechanic ideas.

[Pyrixs]

I'm DMing my first campaign and I want to make a unique mechanic called Profane Knowledge for it. The setting is a world created by Eldritch beings that is intended to be a sacrifice which the players will find out about and earn their first point of Profane Knowledge and then throughout the campaign they can gain more points but I don't know how to apply it. I know I want it to give bonuses but also penalties that scale with how many points. I've placed the restrictions of no 3rd party content and mythic content is only allowed of all players agree to it since two of our group min max their characters a lot. Whether or not players get the points is up to them through their actions so I'm kinda at a lost of what to do or how it would effect them without it rendering their characters useless. Any ideas or help would be greatly appreciated.

[Azothath]

It would be simpler to treat it as a knowledge skill that can run off Knw(arcn, rlgn) at -5. You just set DCs as usual. That lets people decide if they want to put ranks/skill points into Knowledge (Arcana, Profane, Religion, or Sacred).

If you are in an investigative campaign where skills are more used, you might want to review the classes and give them plus 1 to 2 skill ranks per level in knowledge skills or appropriate skills making INT +2 +(1 or 2) focused ranks the baseline. For focus; Craft, Knowledge, Perform, Profession are your skills based on Class theme.

There are Horror Rules for horror campaigns as sanity and madness may prove handy.

Then Occult Rules with skill unlocks.

I personally would avoid Mythic. It just pushes the campaign into soap opera mode where no challenge by CR≤(APL+3) can really tax the PCs, it will be rocket tag combat in 3 rounds or less. But if you want silly and understand the game will blow up sooner than later, go for it. It is a Game.

[DM_aka_Dudemeister]

Maybe something like the Corruption Rules in Horror adventures could work.

Each point of Profane Knowledge increases the corruption, allowing players to choose unique powers, that come at a price?

[Azothath]

If you are running Lovecraftian Mythos, just understand that much of the McGuffins(magic items) are near artifact to artifact class from a PF1 perspective. While the McGuffins are plot drivers, books/movies end but PF1 adventures continue and you don't want these ultra-powerful magic items laying about cluttering up future plots or making things too easy, so clean up after your conclusions. Modules/APs are famous for just leaving them about.

[Goth Guru]

If you have McGuffins for McGuffins' sake sure.
A lot depends on why they created a world with a set expiration date.
Do the gods just want to see fireworks?
Is it a trap for Rovagug? Get him to manifest and delete the whole shebang.
Is it a training ground for outsider warriors recruited on judgement day?

Maybe several deities all agreed on the cutoff date for different reasons.

[Pyrixs]

I am drawing inspiration from the Lovecraft mythos I won't deny, and a lot of it is basically I have a starting point and an end point but I'm giving the players free run of the world with nudges here and there to guide them in the story without hard balling them in the direction of the story. The reason for the world sacrifice is to bring a deity from the Dark Tapestry into the main world. Azothath can you explain your knowledge idea more if it isn't too much of a hassle?

[Azothath]

Azothath wrote:

It would be simpler to treat it as a knowledge skill that can run off Knw(arcn, rlgn) at -5. You just set DCs as usual. That lets people decide if they want to put ranks/skill points into Knowledge (Arcana, Profane, Religion, or Sacred).

If you are in an investigative campaign where skills are more used, you might want to review the classes and give them plus 1 to 2 skill ranks per level in knowledge skills or appropriate skills making INT +2 +(1 or 2) focused ranks the baseline. For focus; Craft, Knowledge, Perform, Profession are your skills based on Class theme.

There are Horror Rules for horror campaigns as sanity and madness may prove handy.

Then Occult Rules with skill unlocks.

...

So let's say my PC Dr. Plockman Wiz 5 found this fine(0-6") sized regular pentagonal greenish stone about 4" thick with several symbols etched onto the top faces.

The GM sets the 'lore' DC at 25 while it is magic but not an artifact, and Spellcraft DC 25. The symbols in Outer Tongue DC 20.
Plockman casts Detect Magic and is dazed for a bit. Now he is really curious.
Plockman knows it's not common as his DC 10 "freebie" the GM remains silent and says "you kneed to make a knowledge check".
GM knows Plockman needs a Knowledge(arcana, profane, religion, sacred) result of 30 (as they are related) or a Knowledge(lore) result of 25 to know the name and general info about it.
Plockman knowing it is powerful casts Heighten Awareness (+2 comp), reviews his books (mwk tools) on Lore gaining +4 crcm after 4 min, then casts Identify (+10) Spellcraft and proceeds with his check.
Plockman rolls a "12" using Knw(arcn) +12 for 12+12+2+4=30, a success but not enough to succeed by 5 to gain another insight/clue.
Plockman rolls a "8" on Spellcraft +12 for 8+12+10=30, a success (DC 25 from above) and discovers the properties and command words of of the item.
Plockman rolls a "7" Linguistics +8 for 15 and fails to comprehend Outer tongue but senses it is close to Aklo. He knows later with Comprehend Languages he can understand it.

With skills like Lore, Profane, Sacred they are "specialized" but related to the more general Arcana and Religion, so there's a 5 DC offset to represent that. If Lore is more esoteric but related to sacred/profane, then you could go offset Lore +10, Sacred/Profane +5, and Arcana/Religion +0.

The difference comes in getting bonuses. Masterwork tools like books are there for arcana or religion but books on Lore will be rare and probably cost sanity to read. You'll have to make up spells (besides Contact other plane) to gain bonuses to Lore.

Lastly, if you Lore is so different than PF/D&D magic you might need a feat to understand its workings, much like the Technologist feat. Sure PCs hated they had to spend a feat, but if it is campaign centric and people want "to know" then it's a balancing cost.