I have a few suggestions, feel free to use them as you like:

Pacifism: determines when it's acceptable to commit violent acts in the colony. It could go on a range from not liking pacifism (people will get upset if they don't see violence for a while), to mild pacifism where it's bad to attack someone while they run away, all the way up to extreme pacifism where fighting back against any attacker is seen as horrible.

Hedonism/Utilitarianism: might work better as a meme but it'd be like a counter to the 'guilty' or 'pain is virtue' memes, where unhappiness and pain are seen as terrible. Could also require that people prefer comfier, more luxurious items too.

I have less specific ideas on this one, but it'd be neat to have precepts tied to how the colony adheres to authority. It could tie in easily with individualist/collectivist, where individualists see the authority figures just as normal people but collectivists revere them and see them as far more important.

Hope this helps! I've been wanting to make a mod that adds precepts myself, but I'm happy to share some ideas!

Eating venerated animal: Range from abhorrent "how could you? it's sacred!" to exalted "let's absorb the powers of our symbol through consumption!"

Superstitious: ideologies that discourage superstition would have no bonuses/buffs from it, so more stable; ideologies that encourage superstition would have pawns occasionally receive random buffs/debuffs. Like, "-2 I saw an ocelot! That's bad luck." or "+5 an aurora overhead! The gods must be please." (not sure if this is doable -- the superstitious part might be kind of complex? I dunno, idk anything about Rimworld modding)

This is really cool! Those are the only suggestions I have but I'm eager to see what comes of this mod in the future. :)

1. Handling the Dead: Cremation only? Burial only? Leave them where they lie, undisturbed? Mood debuff if all that delicious soul is wasted by not cannibalizing it? And similar options. An ideologion that demands the dead be buried and respected would potentially lead to a massive necropolis, for example... which is a pretty cool mutation of the default gameplay, for just one precept. This goes well with...

2. Grave Sites: An ideoligion that finds grave sites beautiful might bury their dead among the colony itself, as a kind of decoration. Or maybe they demand colonist grave sites be beautiful, leading to the creation of mausoleums or leaving natural spaces for grave sites. As opposed to a superstitious view of grave sites, whereby pawns will have a debuff if they pass too near a grave site, or a corpse left untouched as their ideoligion demands, etc.

3. Affinity for Destruction: Pawns might have a mood buff for witnessing an explosion, a fire, lightning, firing a mortar, etc. Incinerating enemies in flames or blasting them with mortar fire would be a bigger buff. This is a little wild, of course, but an ideoligion based around big guns, artillery, and IEDs changes the core gameplay in an exciting high risk high reward way. Another culture might find massive, impersonal means of destruction abhorrent, much like those who dislike automated turrets.

4. Affinity for Trade: An ideoligion might consider trade and economics to be a driving force in the universe and feel driven to trade as much as possible, leading he colony to emphasize producing trade goods and running caravans. By contrast, they might prefer to be fully self-sufficient, or possibly that trade is an inferior, weaker version of taking things by force.

5. Aesthetics: Beautiful people could be revered and desired by the community, and seeing ugly people might give a mood debuff beyond the usual relation penalties. Or, perhaps one ideoligion doesnt care about beauty at all in people. Maybe there is a high value placed on beautiful surroundings, amplifying the buffs from being in such spaces, but adding a small constant debuff when not in such a place... as opposed to a society that is extremely practical and minimizes buffs and debuffs for beauty/ugliness to something more neutral.

Filth


Abhorrent: Living in filth is worse than death.

Hated: ??????

Disliked: It's good to clean up after ourselves.

Acceptable: Our living space doesn't need to be spotless.

Liked: Dirt is dirt and dirt don't hurt.

Loved: ??????

Exalted: Clean surroundings lead to unclean thoughts.

I really would like Marriage, ranging from its shameful to be single to marriage is an abhorrent ancient ritual. It would be even better if it was gender specific!

Praise the sun: basically the opposite of the Darkness meme

Law and order: thoughts on imprisoning guilty criminals/ colonists or letting them leave (severe if they fled with loot or kidnapped sb); freeing prisoners after their sentence

Mutism: spiritual mutism; variant of blindsight

Nomadic: Need to change settlement location once every few years or even more often

Dont know if some of these concepts are already partially included in vanilla since I havent played that much with ideology

Sun/sky worship: Small mood buff for working and sleeping outside/debuff for being indoors. Workbench penalties swapped for indoors/outdoors. Platform burial/outdoor cremation. Rain dance ritual.

Harvest: Increased crop yield, ritual planting/harvest times. Fertility ritual/harvest festivals. Wicker Man sacrifice at the end of the season to bless fields for the next year's harvest.

Culture: Favor specific style or wide variety of art in colony, debuffs if no art or wrong art present. Slower art creation with higher end quality. Colony desire to purchase/raid new artworks from other settlements, refusal to sell artworks. Requirement to produce high quality art each season.

Epicurean: Desire for high quality meals at all times, even for prisoners/slaves. High debuff for serving paste, low debuff for eating simple meals. Longer cooking times yield lower food poisoning chance. Vomitarium building for lengthy Roman-style food orgies.

Scavenger/Dumpster Diver: Disdain for crafting colony items, preference for stealing/repurposing/purchasing items from other settlements/ruins. Furniture slowly degrades in colony even indoors, requiring regular repairs. Crafted items start at lower quality/negative beauty, but repeatedly refurbishing low-quality items has a chance to increase quality/beauty.

Luddism: Rejection of Modern Technology. The presence of industrial tier technology, use of electricity, industrial weapons, etc... is something the pawns find abhorrent and disgraceful and they want to live, at best, with medieval tech. I've done this voluntarily with a colony and so far it has been kind of successful despite the high amount of mutilated people and my food constantly rotting in my storage.

Pawns would get stacking debuffs by seeing modern appliances around like heaters, coolers, electric production facilities, electric appliances... Or they would just not be able to research electricity and not get industrial tier techs.

Some great ones above already! I'll add these:

Slave Gender: Only Male (strict) [female slaves impossible], Only Male (relaxed) [female slaves give mood debuff], Any Gender, -same for female slaves only-
Marriage Type: Only Homosexual, Any, Only Heterosexual
Physical Love Type: Only Homosexual, Any, Only Heterosexual

I'd like to expand on the "Formal Relationship" Types further:

- Marriage: (I view the one spouse to unlimited spouses as its own category) - spouses are more viewed as equals as opposed to members of the harem

- Harem: (from two concubines to unlimited - can select if you want the harem to have a chief spouse, etc.) - mood buffs and penalties depending on position in the harem (e.g. Master/Mistress of the harem [mood buff], chief spouse [mood buff], concubines [mood debuff if concubines are colonists, if concubines are slaves, should cancel out the mood debuff for sleeping in the same room as a slave, I think asking for sleeping in the same bed as a slave might be too difficult as that is not available in the vanilla at the moment]

- Both types of relationships should be able to exist in the colony but the harem only shows up when the male/female supremacy meme is selected
- Should be able to select if marriage/harem is available for different groups (e.g. regular colonists can marry but only those with special roles can have a harem, etc.)

Slave-only rituals and clothing (this might be complicated because you're only allowed 6 rituals) but I want to be able to sentence slaves to be scarred, have specific clothing requirements, etc.

I was thinking it would be cool if there was an implemented option for a caste system where specialist roles get extra buffs and colonists without a role would get a mood penalty. Could have its own meme or could be unlocked by collectivism.
I also don't know how hard this would be to implement but I thought it'd be cool if there were precepts for desired colony size, on one end you could get buffs for having very few colonists and penalties for having too many, and on the other end you could have buffs for having lots of colonists and penalties for having too few. could be called "large community: disliked" and "large community: preferred" or something like that.
Lastly, I just want to strongly second the idea of a precept that gives buffs to agriculture, like the mining speed precept for tunnelers.

can you add a meme called "Explorers" where your colonists like or need to go on a caravan or settle in a new area and get a fairly sizable mood buff if they do but if they don't for like a week then they get unhappy

Can you add one for incest? in the base game it is abhorred by everyone.

Not exactly a precept, but it would be cool to allow insects to be venerated.