Eating a monster egg (possibly after using some cooking system to prepare it) has a chance of giving you some intrinsics that the monster corpse can ordinarily confer.
Cursed potions of invisibility remove any permanent intrinsic invisibility you have, but still give you the normal cursed duration of temporary intrinsic invisibility, so after that duration you will become visible again. Thus, they are a controllable way to remove the permanent intrinsic and are also still useful for characters without invisibility yet.
Magic traps can toggle much more types of intrinsics than just invisibility or see invisible. Probably not all intrinsics but at least many types of resistances.
Make it impossible to have fire and cold resistance intrinsically at the same time. If you eat a corpse that gains you one, you lose the other. Things like crowning that give you both now do not give either (unless perhaps you have neither, in which case you get a random one).
Extrinsic fire and cold resistance are not affected. This makes it valuable to have those extrinsics from a ring, underused colors of dragon armor, or an artifact.
All polymorphable monsters that currently resist both fire and cold must have one of those resistances taken away; otherwise you could have both at once by polymorphing into them.
Intrinsics that you can gain from eating that do not give you some increment of a percentage (for instance, teleport control) are impossible to gain as a permanent intrinsic. Instead it will always time out.
The current resistance system is unsatisfying, because most resistances separate the effects of something into a binary outcome: worse effects with no resistance, totally ignorable effects with it. Most resistances also are get-once-and-be-protected-forever, which is uninteresting in the long term.
Proposed solutions to this generally assume that there will be some distinction between resistance and immunity, which offers better (or total) protection but is not normally obtainable as a permanent intrinsic effect. This also enables partial resistances (as found in SporkHack) to be used, though some ideas still treat them as binary - either you have it or you don’t.
Dragonbane starts off as just a weapon with a damage bonus versus dragons, but it gains properties corresponding to every type of adult dragon you have killed with it. So when you kill a red dragon with it, it now gives you fire resistance and/or does fire damage, then you kill a black dragon and it now gives you fire and disintegration resistance and/or does fire and disintegration damage, and so on.
This doesn’t have to be Dragonbane, the concept of an artifact that powers up by killing different monsters could apply to something else, but Dragonbane is a good example since dragons have a big diversity of obvious properties and resistances.
To keep it from becoming overpowered, it could stack up to 2 or 3 properties from the last 2 or 3 unique types of dragons killed so long as neither property is something powerful like reflection or magic resistance (which would clear all other properties).
You can get some rare intrinsics by eating artifacts that confer them. For instance, eating Excalibur could give level-drain resistance, or eating Grayswandir could give hallucination resistance.
The chance would be much less than 100%, possibly even lower than the standard odds of getting an intrinsic from eating jewelry.
Remove all ways of immediately acquiring a permanent intrinsic (potion, corpse, wand, whatever). Instead, at some unpredictable point after you’ve cumulatively had that intrinsic for a couple thousand turns, you gain it permanently.
A damage type that shuffles around the player’s intrinsics, never taking any away for a net loss, but always rearranging them, so you could lose fire resistance but gain teleport control, or lose telepathy in exchange for intrinsic protection from shape changers.
Assuming a monster intrinsics implementation: When a gremlin steals an intrinsic, it gains that intrinsic (if monsters having that intrinsic is coded).
Chromatic dragon scales or scale mail, rather than providing all resistances at once, can be invoked to choose which one resistance it will provide. This resistance remains active until the next time you invoke it.
Lava gremlins: a different gremlin species that reproduces in lava instead of water. It has at least one physical damage attack and at least one fire attack, and the regular gremlin intrinsic-stealing attack, except they steal intrinsics during any time that is not night.
Triggering an anti-magic field, in addition to draining some of your energy, removes any magical buffs or debuffs applied to you, similar to how cancellation works as described in #2673.
Monsters can now zap cancellation at the player; effects of cancellation on the player include draining Pw (and possibly maximum Pw if Pw hits 0) and removing magical temporary intrinsics such as invisibility, speed, and detect monsters. It does NOT cancel the player’s entire inventory, as this does not happen when the player zaps cancellation at a monster.
Add a potion of resistance, which provides a cocktail of basic resistances (things like fire, cold, shock, sleep, and poison) for a limited time. In order to make this more useful and not just yet another candidate for stashing away, possibly all roles start with it identified.
You can wish for intrinsics. This gives you any intrinsic that you can actually get in your normal form. Wishes for intrinsic reflection, drain resistance, and the like will be unsuccessful. Not sure about intrinsics normally only possible by eating jewelry.
Monster spell that either generally or specifically debuffs the player. It targets beneficial timing-out intrinsics you have, such as speed, detect monsters, and see invisible, and reduces their time remaining, possibly removing them outright. Does not affect permanent intrinsics or extrinsics.
Spells that give temporary to-hit or damage buffs. Must be carefully balanced; this is intended for fighter roles more than wizards. It also shouldn’t last long enough or be cheap enough to be perpetually castable.
Generalize cockatrice-egg mechanics to all eggs: eggs of acidic monsters will be acidic, eggs of poisonous monsters will be poisonous. Possibly even have a (reduced) chance of getting intrinsics from a monster egg.
Monks can gain intrinsic immunity to just about everything by leveling up, but most of these are nullified if the monk is wearing body armor.
Anti-magic fields end a bunch of temporary magical intrinsics, such as speed or see invisible.
Status effect that temporarily lowers all attributes to 3.
Use timing-out intrinsics (beneficial ones gained from corpses) to invert the hunger clock: use the limit on how fast you can hunger as a restriction on how many intrinsics you are maintaining.
Black pudding globs convey only one of the three intrinsics they currently convey (maybe shock resistance), and brown pudding globs convey another (maybe cold resistance).
Amplification trinsic which is a counterpart to reflection: an attack that hits you will be amplified and continue past you (greater range and greater effects).
Make being on fire a status effect, which deals damage over time. (Other obvious things to make into damage-over-time effects: poison, bleeding/internal damage.)
The scroll of destroy armor, when confused, cursed, and naked, grants temporary disintegration resistance.
Split up the effects of magic resistance, as it is too extensive. It protects against magical force, death magic, teleportation, polymorph, etc.
The timeouts for intrinsic invisibility and see invisible from eating a stalker corpse should be very long.
