A variant cursed effect of a scroll of genocide: it removes most monsters of a given species, but sends the survivors to you looking for revenge.

A cursed amulet of reflection will behave as an “amulet of absorption”: instead of reflecting rays, nearby ones that weren’t going to hit you get redirected towards you instead. Also, rays that hit an amulet of absorption wearer don’t continue past them.

Alternatively, add the amulet of absorption as its own item, and make it usually generate cursed like other “bad” amulets.

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.

The scroll of gold detection, if read when confused (and cursed, possibly), detects silver items instead of gold pieces.

It’s probably desirable to keep the existing effect of trap detection in some form, so it’s a bit tricky to decide exactly which combinations of cursed and confused should keep that and which should detect silver.

Additional YAFMs that may replace the “You hear your heart beat” message for applying a cursed stethoscope at yourself:

• If hallucinating, “You hear a soothsayer with the weather forecast.” This is followed by either “Gehennom will get a rain of burning pitch later today.” or “The dungeon will be cool, with a stony gray overcast.”
• Otherwise, if undead, “You hear the ocean’s roar.”
• Otherwise, if a Wizard, “You hear yourself mumbling curses.”
• Otherwise, the usual heartbeat message.

Cursed tonal instruments are incapable of playing notes, and instead just make noise.

Cursed boots that you have worn for at least 300 turns should emit a stinking cloud when finally removed.

Cursed stethoscopes cosmetically stick to your hand when used, but you rip off some skin to get it off when you’re finished using it, which deals 1 damage every time you use one.

Zapping a cursed wand of make invisible turns invisible things it hits visible. (Or possibly transfer this effect to the cursed potion, since wand effects generally do not vary with beatitude).

You can throw cursed aklyses, because the tether is still welded to your hand. Because of this, they always return – which means there actually might be some circumstances where it’s beneficial to wield one versus a non-cursed one, for example attacking monsters in water or lava.

To compensate for this a bit, the cursed aklys could have an increased chance of hitting you when it returns.

Cursed arrows fired from a blessed bow or vice versa do not misfire.

Cursed bags of tricks create tame monsters instead of peaceful or hostile. This is a “bad effect” since you cannot use them for sacrificing.

Eating cursed rings or amulets gives the opposite of the normal effect (likely stripping an intrinsic instead of gaining it).

A cursed magic lamp may generate a demon lord (possibly pacified) instead of a djinni when rubbed. Possibly you could read the lamp to see the name of the demon lord it contains.

If you get hit by a cursed rock from a falling rock trap, you may become stunned for a few turns.

Weapons no longer stick to your hand when cursed, because that just makes the game less fun and strongly discourages experimenting with random weapons lying around (there are good weapons out there, but the risk of either ending up with a bad welded weapon, having to spend resources to get it unstuck, or spending identification resources on making sure it’s safe) means no one will give them a try. Instead, replace that behavior with a variety of other effects:

• The weapon occasionally turns on you when you try to attack with it, hitting you instead.
• The weapon occasionally deals an extra 1d8 shock damage to you and your opponent when it hits, possibly breaking rings.
• The weapon wakes up any sleeping monster you get near. Doesn’t actually identify as cursed until it wakes something up.

None of these are intended to be immediately obvious. While they are like object properties, they don’t necessarily have to be implemented like those: the curse behavior of a weapon could be deterministically computed from its object id hash.

Cursed wind instruments (bugle, whistle, most horns) stick to your face when used, preventing you from using #chat or making other forms of conversation (to shopkeepers, demon lords, priests, etc, though most of these are ambiguous on whether the hero needs to speak) and possibly also preventing eating.

Alternatively, using the cursed wind instrument could simply produce “You hurt your vocal cords!” and make you mute for some length of time.

Armor and weapons are heavier when they are cursed than their normal weight.

Breaking a wand of wind creates a stinking cloud centered on its space, because it’s “breaking wind”. Possibly only when cursed.

Corpses dropped by zombies are always or often cursed. Removing the curse from them makes them less likely to revive. This could even be made as strict as every time a zombie drops a corpse and a revival timer is actually set on it (as opposed to a rotting-away timer), it is made cursed.

Carrying a substantial number of cursed items in your inventory has some denigrating effect on you. One suggestion is that enough cursed items counts as a negative luckitem similar to a cursed luckstone.

Applying a cursed horn of plenty will cause it to vacuum up food items in your inventory or the surrounding area.

A cursed amulet of life saving, if saving you from HP-loss death, will restore a completely random amount of hit points.

Any cursed object, not just weapons, welds to your hands if you wield it.

When you first open an ice box that generated cursed, it may spawn a gelatinous cube or a group of P monsters.

When opening a tin with a tin opener, the beatitude of the tin opener is added to the tin similar to how markers and scrolls work (e.g. a blessed tin opener opening an uncursed tin will treat it like a blessed tin).

Playing a cursed tonal instrument accepts your input sequence of notes, but then prints “Your finger slips. You play ‘XXXXX’ instead”. This is either a random sequence of notes, or a sequence which is mostly the same as your intention but with one or two notes shifted slightly.

“Partial” magic mapping from a cursed scroll maps a contiguous chunk of about 1/7 of the map, rather than random tiles.

Wearing cursed rings causes you to hunger slightly faster than if they weren’t cursed.

A cursed potion of enlightenment grants you temporary darkvision.

Cursed two-handed weapons only weld to one hand at a time, allowing you to do things with the other hand. The only way to have no free hands at all is to wear a cursed shield and wield a cursed weapon.

Monsters pulled out of a bag of tricks are tame whether the bag is blessed or uncursed, and hostile only if it is cursed; however, all monsters created by it are temporary and disappear after several hundred turns.

Applying a cursed bag of tricks may make it bite you rather than releasing a monster, making you drop the bag. This does not use a charge.

Applying a cursed bag of tricks sometimes causes it to explode, causing magical explosion damage to you while also expending all of its create monster charges at once.

Enchanted boomerangs can continue flying after hitting a monster, with an enchantment/7 chance. (Add 2 to the effective enchantment if the boomerang is blessed; subtract 2 for each successive monster it hits.) If the boomerang is cursed, enchantment doesn’t matter - it will always fall on the first hit.

The reason behind this is twofold: because it makes boomerangs a more attractive weapon, and for the slapstick comedy value.

Dipping a unicorn horn into a potion of a type it normally “cures” will do nothing if the potion is cursed.

Beams and rays from wands have a slightly reduced range if the wand is cursed, and a boosted range if it is blessed.

Attempting to pick a lock with a credit card may result in it slipping through the crack (ending up either inside the box or on the other side of the door). The chance for this is getting a 1 on a rnd(Dex*2) roll (with an uncursed card; cursed cards will always slip through and blessed ones will never slip through). If fumbling, use Dex/4 instead of Dex*2.

Object materials: cursed gold items cannot be dropped.

When you put on cursed gear or worn gear becomes cursed, it gives you a message that it welds to the appropriate body part. When becoming uncursed, it gives you a message that it is no longer welded.

The cursed scroll of remove curse removes the curse from one item in your inventory at random, to give it at least a tiny bit of use.

Cursed potions of gain level work in Sokoban, but they always place you on the downstairs of the next level up instead of randomly, effectively letting you skip any level except the last one.

Blessings or cursings on spellbooks does not translate to automatic success or failure. Instead, it acts as a fairly large bonus or penalty to your effective Intelligence when reading it.

Confused cursed scroll of punishment decreases god anger by 1.

The scroll of teleportation now levelports when blessed and limits your possible teleport destinations to a small radius when cursed. Confused teleport gives you a single controlled horizontal teleport.

The “weakest” beatitude of the potion of acid (usually blessed in vanilla, but if #1918 is implemented it will be cursed) may not cure stoning.

Swap the blessed and cursed effects of the potion of acid, which means that blessed acid is more powerful acid, while cursed acid is kind of cruddy.

Hitting monsters with a non-cursed unicorn horn cures them of status afflictions. Hitting them with a cursed horn gives them status afflictions.

The cursed Book of the Dead will occasionally raise the dead around its location on its own without warning.

Flip the blessed and cursed effects of the scroll of create monster, with the argument that if beatitude influences an object’s effects at all, blessing should amplify them and cursing should reduce them.

However, consistency along these lines conflicts somewhat with the current behavior of objects, which is that blessing generally always gives the player a better effect and cursing gives them a worse one. The create monster scroll is in a weird place because both its blessed and cursed effects could be considered beneficial in different contexts.

Gold nuggets as a replacement for loadstones. They are expensive, but heavy, and generate cursed. Like loadstones, cannot be dropped when cursed.

Whetstones, imported from SLASH’EM, but with some additional effects.

• The behavior from SLASH’EM is that whetstones can be used at a water source to remove rust and negative enchantment from edged weapons and pick-axes.
• Cursed whetstones either weld themselves to your hand or have a chance of breaking a weapon rubbed on them.
• Blessed whetstones can uncurse a cursed weapon rubbed on them, but at the cost of removing the whetstone’s blessing.
• If slingshot is implemented, rubbing rocks on a whetstone will break them into slingshot.

A cursed bag of tricks can be applied at monsters to eat them up, which will add one charge to the bag. (The existing behavior of applying a cursed bag of tricks producing a monster like normal is suppressed.)

You can apply a cursed bag of holding (or possibly empty bag of tricks) at a ghost to capture a ghost, which can then be used to recharge a wand of undead turning.

You can only use cursed potions of gain level once or twice while carrying the Amulet. After a few uses, the Amulet will start to pull you back down as you rise up, wasting the potion.

Cursed weapons deal bonus damage to all angelic beings, like blessed weapons do to undead and demons.

Cursed amulets of life saving allow you to remain in the game, at the cost of bringing you back as a skeleton.

Karma stone: a type of gray stone that, if it is blessed or cursed, can be rubbed on another item to transfer the blessing or curse to that item, making the stone uncursed in the process. Cursed karma stones in inventory eventually transfer their curse to a random item on their own; the stone might remain cursed after doing this. The loadstone in the Mimic of the Mines is replaced with one of these.

Quaffing cursed invisibility removes the invisibility intrinsic if you had it. Possibly the same for see invisible.

Give cursed wands some bad effects other than rarely exploding, such as a cursed wand of fire also hitting your own inventory.

Attempting to light a cursed lamp or candle may burn your finger, dealing a little bit of damage: “Ouch! You burnt your finger!” (No damage if you are fire resistant).

Dipping cursed unicorn horns into harmless potions turns them into harmful potions.

Using a cursed tonal instrument makes the gears and tumblers in the castle drawbridge lie to you.

The scroll of create monster now summons only 1 monster (occasionally 2 or 3). The beatitude determines whether they will turn out allied with the reader (blessed), created normally with the usual probabilities of being peaceful (uncursed), or whether they will be hostile to the reader or omnicidal (cursed).

Gold objects deal extra blessed damage and extra cursed damage (i.e. extra damage from wielding a blessed weapon versus undead will be enhanced if the weapon is gold).

The cursed potion of see invisible removes any see invisible intrinsic that the player has.

The scroll of destroy armor, when confused, cursed, and naked, grants temporary disintegration resistance.

Change up and add new failure effects of spellbook reading:

• Any failure confuses you instead of paralyzing.
• The level 5+ confusion effect seems quite tame in comparison to the other effects, so replace it with paralysis.
• New effect: book tries to eat you
• New effect: level drain
• Spell enters your head automatically, but erases your knowledge of one/all of your other spells. (This could be quite annoying and may be better off as an Evil Patch Idea.)
• New effect (possible in combination with other effects, and for any book): book curses

Books no longer have a 1/3 chance of disintegrating when failing to read them; instead, a cursed book will always disintegrate.

Cursed potions of gain ability give you an ability point in something by taking it away from one of the other scores.

For variants with scrolls of consecration, the confused effect will remove the graveyard flag from a level if non-cursed, and add it if cursed.

The scroll of remove curse’s blessed effect is transferred to its uncursed effect. The blessed effect is now to uncurse everything in inventory, and then bless a few items. The cursed effect now randomly curses inventory as the curse items spell would do. May need to make this scroll rarer or more expensive to write in order to keep it balanced.

Blessed potions of polymorph, when quaffed, grant you immediate polymorph control over just that one polymorph either 50% or 100% of the time. To compensate, cursed potions of polymorph will ignore changing into a dragon and will try several times to roll a monster that will make you break out of your armor. Or the cursed potion could have a wildly variable duration, so you have no idea when it will end and cannot rely on it.

Sickness resistance negates the effects of potions of sickness. However, a cursed potion of sickness will now give you fatal illness instead of the normal poison effects.

Some version of key breaking, perhaps when trying to use a cursed key. However, this should not go the SLASH’EM route of allowing any unlocking device to break, since that just makes the player carry around extra keys. Skeleton keys should be made of bone and can break. Perhaps add a new key that is not breakable but is rarer than skeleton keys (stealing some of skeleton keys’ probability).

Lock picks and credit cards should possibly be able to break too.

Opening a cursed bag of holding does not tell you what has disappeared, or it just says “Things have disappeared from the bag!” without describing them.