New conduct, permaconflict, which must be enabled by setting an option. If you play the game with this, you constantly generate conflict, which likely makes some aspects of the game much easier and some much more difficult.

Not specified whether the permanent conflict would cause extra hunger like the ring does, or not cause any like artifacts do.

“Priest of Flame” conduct, only available to Priests: they start with a lit candle or other source of flame, and must keep a lit flame on them at all times to maintain the conduct.

A carrion-eater conduct in which your only source of nutrition is allowed to be corpses. No permafood, juice, prayer or anything else.

Scavenger conduct: never take an item from a shop or a chest (notably, this means you cannot take the wand of wishing).

“Saintly” conduct, which tracks that you have never abused your alignment.

“Psuedopacifist” conduct - you are allowed to kill monsters, but only in self-defense. This means you cannot kill a monster which generated peaceful, even if you anger it, and you cannot kill monsters which are incapable of taking action to harm you such as blue jellies.

Vow of poverty as a conduct. It is broken by ever having money in inventory (with a grace period of a few turns at the beginning of the game for roles that start with money, or define the conduct as never having money enter the inventory so you can spend initial gold, or a roleplay option similar to nudist that prevents you from generating with any money).

Track not buying protection from a priest as a conduct, as a weaker version of atheist.

New “pauper” conduct, in which you are not allowed to gain any gold pieces in your inventory (gold items like the gold ring and Candelabrum are fine, because they aren’t money).

An interesting side effect is that you can’t sell things in a shop since the shopkeeper will give you money directly for them, unless you manage to somehow remove all the shopkeeper’s gold, enabling you to sell and buy things for store credit.

New “true vegan” conduct, which is broken by using any animal product whatsoever, such as leather-based armor, anything made of bone including unicorn horns, anything made of dragonhide, tallow candles, etc. Picking up the items is okay but applying or equipping them is not.

Track a “magic resistance-less” conduct. It’s not actually broken by obtaining magic resistance at any point; it is only broken when magic resistance changes or negates an effect such as a polymorph trap or touch of death.

Giftless conduct, which is broken when receiving divine gifts from sacrificing. Possibly also when receiving an artifact via crowning.

A “never wore dragonhide” conduct, which includes “natural” dragon armor items like scales and scale mail.

Digless conduct: never dig any tile by any means (digging implements, wand of digging, spell of dig). Monsters digging don’t break the conduct.

Taciturn conduct, which requires that you not use your voice at all. This mostly means that you can’t #chat with things; there probably aren’t currently enough things in the game which require or incentivize speech to make such a conduct meaningful. To that end, a useful #chat system that lets you do many things with many types of monsters (e.g. the one described in #2576) would be useful.

Certain messages like “You scream in agony as your body begins to warp” would need to be changed to special YAFMs if you have taciturn conduct intact.

Polymonsterless conduct: you never intentionally polymorph a monster. (Though defining “intentionally” is probably quite tricky.)

Petless conduct: increment when the player starts with a pet or tames a monster.

This conduct could be accidentally broken by the taming effect of a magic trap, which is problematic. One solution is to have magic traps pacify instead of tame if the player has the pet option turned off, but mixing options and gameplay like that seems like a bad idea. Worth noting that polyselfless is another example of a conduct that can be broken accidentally and is far more likely to happen. Note that xNetHack’s implementation of petless conduct just turns the charismatic magic trap effect into a pacification of adjacent monsters regardless of whether you’re petless or not.

Another issue is the guardian angel; it would be especially cruel to unexpectedly break the conduct on the final level of the game. xNetHack’s implementation prevents the angel from appearing if you still have petless conduct intact when arriving on Astral.

Artifactless conduct: is broken whenever an artifact enters the player’s inventory (since the player never has to pick up an artifact).

True pacifist conduct, which prohibits you from directly hurting any monster.

A conduct that is broken if you use a unicorn horn. (Possibly, only if you get healing effects from a unicorn horn; using it as a weapon is fine.)

Conflictless conduct: never have a monster attack another monster while influenced by conflict. Would be best if you can safely ring-test conflict, perhaps it gives some message like “You feel aggravation” or “You feel irate” when wearing it (these messages would be shared with the ring of aggravate monster so as not to be unambiguous).

Track “did not enhance any skills” as a conduct.

New conduct for not hitting things with thrown items, and another conduct for not casting offensive spells.

Split weaponless conduct into melee-weaponless, ranged-weaponless, and spell-less conduct.

Conduct that tracks whether you ascend with your original pet. (Though this isn’t really in line with the other conducts, since it doesn’t require abstaining from anything. It might be better off as an achievement.)

A colorless or colorblind conduct, settable with OPTIONS=colorblind or something similar at the start of the game, as a permanent affliction. When you are colorblind, it is as if the color option is forced off, and any items with colorful random appearances cannot be distinguished from one another (all gems are just “a gem”, all colored potions (but ‘‘not’’ ones such as fizzy, bubbly, white, black) are just “a potion”, ditto for colorful spellbooks) until formally IDed. Figuring out how calling object classes works might be tricky, because having it work as it currently does would mostly nullify the identification challenges of being colorblind.

Add a conduct for tracking whether the player has not used any of each class of objects.