Some mechanic (maybe involving forges?) that consumes valuable gems to add enchantment to weapons or rings, because gems tend to become useless at a fairly early point in the game.

Track the highest-reached enchantment of enchantable weapons and armor. If it gets cancelled or disenchanted below this peak amount, you can dip it in a potion of restore ability to immediately raise it back to that peak.

A random set of monsters, deterministic based on their ID number, will not throw a weapon that is usable for both melee and throwing (e.g. dagger, spear) if they have no other melee weapon. Probably over half of monsters should behave like this, but some monsters will indeed continue to throw their last dagger at you.

The enchantment on non-blessed weapons degrades by 1 point after a certain number of hits, roughly 100. Cursed weapons degrade in half the number of hits. Possibly, this auto-identifies the enchantment when it happens.

There could be some mechanism to prevent degradation by resetting the counter on a weapon, such as using a whetstone on it. (Not that this makes sense for non-slashing weapons.)

Take a page out of Brogue’s book for streamlining weapon identification: after a certain number of attacks, hits, or kills with a weapon, the weapon’s enchantment (but nothing else about it) becomes identified.

Possibly, it could take less time to identify a weapon the higher the absolute value of the enchantment. It should be pretty easy to tell that a weapon is really bad or good, compared to middling.

Behavior is undefined regarding stacking. E.g. if you drop 9 of your 10 daggers, use the other one a bunch, and come back to pick up the 9, should they still stack together? If not, it would make using stackable weapons very annoying. If you use the one dagger enough to identify it, should the others automatically become identified? Only if you try to stack them together? Not at all?

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.

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

When you begin the game as a monk, you are prompted (if you have not already configured in .nethackrc) whether you want to be a weaponless monk or a weapons monk. Using weapons when you have chosen to be weaponless, or vice versa, you take alignment penalties.

Elves can read the runes on any elvish weapons (and probably also the runed wand). This doesn’t have to say anything important, it could just describe the item.

You can use a forge to combine elemental wands with weapons, destroying the wand and conferring an object property of cold, fire, or shock on the weapon.

Ghosts, shades, and any other incorporeal monsters can’t wear armor or wield weapons. (With a possible exception if it’s cursed.)

Piercing weapons never generate as gold, because gold is a terrible material for maintaining a sharp point. Either that, or using a gold piercing weapon to attack things regularly decreases its enchantment.

Squirt gun: a weapon which can be loaded with a potion (using up the potion), giving it ammo for 5-10 shots. When you fire it, a liquid projectile flies through the air, and causes potion effects (identical to those of throwing a whole potion) to whatever monster it hits.

It would be silly to define a separate liquid projectile object for each type of potion; probably the best implementation would be to have a single “splash of potion” object and use some field on the object, like corpsenm, to track what sort of potion it is.

Loading water into the squirt gun can be used to discipline pets.

Put a cap on the number of weapons in a stack that can be enchanted by a single enchant weapon scroll. Maybe 20 for ammunition and 5 or 7 for other stacking weapons like daggers. It’s odd that you can multiply the total amount of enchantment points you’re getting just by wielding a larger number of weapons.

When you switch from a one-handed to a two-handed weapon and you are wearing a shield, you are asked if you want to remove the shield, and if you say yes it is automatically unequipped before wielding the new weapon.

Ballistae, a very large and heavy weapon that takes time to set up and prime, but can be used to launch javelins to deal a large amount of damage. Giants can wield them like crossbows. May appear as defenses in special levels like Fort Ludios and the Castle.

Revamping melee weapons:

1. Slashing (swords, axes) and blunt weapons (maces, flails) deal about the same base damage.
2. Swords’ main advantage is that they have a high chance of inflicting bleeding. Blunt weapons have a very low bleed chance but armor reduces their damage a lot less.
3. Bleeding steadily decreases the HP of the bleeding creature. It’s debated whether this should remove a few HP per turn (which would require increasing the HP of everything by a factor of 10 or so) or whether there should be a random chance (around 10%) of losing 1 HP on a given turn. (Possibly an algorithm that makes a monster lose 1 HP on one turn in every 10 - but the exact turn of HP loss isn’t predictable. For instance, if hash(monster id + (turns / 10)) % 10 == turns % 10, lose HP due to bleeding on this turn.)
4. Certain monsters are immune to bleeding, notably undead, golems, elementals, and others that don’t have vitals of any sort. These tend to be better killed with blunt weapons.
5. Bleeding can be fixed (or at least stanched) with bandages. Cloth items can be torn up to make bandages.

Revamped combat system:

1. All melee attacks randomly select a specific area of the body to hit, as well as regular misses, all out of the same pool.
2. Higher skill biases the pool “inward” on the body - some of the miss percentage will turn into outer limb hit percentage, some of the inner limb hit percentage will turn into a body hit percentage, etc. Head strikes are rare, but can inflict stunning as well as damage, although helms mitigate this somewhat.
3. Armor protects the area it covers, but its material or AC is a big factor in damage reduction: weak cloth armor takes full damage just like no armor, plate armor generally reduces damage completely except for rare armor-chink hits, etc.
4. Armor is strictly organized into four tiers of cloth, leather, mail and plate.
5. Positive weapon enchantment lowers the armor’s effective tier. Positive armor enchantment raises its effective tier. High armor enchantments are made substantially harder to come by.
6. Thrown daggers and knives are effectively useless against mail and plate armor, except for rare chink hits. Bow and arrow is useless against plate armor unless enchanted. Crossbow, however, is still useful against it. However, a successful shot deals a lot of damage.
7. On the monster side, many monsters (e.g. dragons) have effective full-body enchanted plate. Some monsters such as giants may also have powerful attacks that bypass armor.
8. Along with the limb-targeting system, it is also possible to break limbs. Broken limbs can be cured with prayer or most types of healing.

Dipping a weapon into a fountain can as a random effect raise its enchantment by one, to a maximum of +1.

You can use #force to pry open doors with edged weapons; however, this requires more Str and has a higher chance of breaking the weapon (perhaps dependent on the weapon’s weight.)

A weapon slipping out of your hand due to greasy fingers overrides it being welded to your hand by being cursed. Thus, you can get greasy fingers intentionally to get rid of a cursed weapon.

Weapons and armor that generate in shops can be randomly eroded at any erosion level. Perhaps 10% or 20% of items are eroded, the rest are not.

Unicorn horns are a one-handed weapon that does 1d3 damage, and train no skill (the skill is removed outright). However, when wielding one without gloves, you automatically “apply” it (not consuming any turns the same way as a stethoscope), every turn.

Chain whips and silver chain whips, which use whip skill.

Blowguns, a weapon which can be used as a launcher for darts. (Cavemen can thematically use these.)

Monsters that generate with weapons should automatically be wielding those weapons, unless they generate asleep or peaceful. The player shouldn’t get a free turn while they use theirs to wield the weapon (notable with player monsters on Astral).

In an effort to make unicorn horns not infinitely usable but also preserve their other good qualities: Split the unicorn horn into two items, the horn, a simple tool which now has a number of charges, and a “unicorn spear” / “hardened unicorn horn” which is a weapon.

Both items have the same base damage, are two-handed, and use the unicorn horn skill, but reading a scroll of enchant weapon while wielding a unicorn horn will transform it into the weapon version like how crysknives work. The weapon cannot be used to cure ailments.

Frisbees, a plastic weapon using boomerang skill. Deals only 1d2 damage, but can fly in a straight line at extremely long range. Frisbees thrown at dogs might tame them.

Rather than making weapons train 1-to-1 on all successful hits, make them train differently:

• Weapons train only when their natural damage die rolls a 1 / rolls a max (ignoring other weapon damage bonuses), so that weaker weapons train faster than stronger ones, and weapon skill for stronger weapons comes in later in the game rather than having all players reach Expert relatively early in the game. This has the oddity of incentivizing orcish weapons over regular, elven or dwarvish though.
• Make the enchantment of your weapon irrelevant to training or even make training slower with a positively enchanted weapon; if the weapon has magical homing assist technology, you’re not really building skill in how to use it that much.

Weapon differentiation - possibly a replacement of the old D&D “damage vs. small / damage vs. large” system currently in use. Weapons would do the same damage regardless of what size the target is, but might get a damage bonus or penalty based on if the target is vulnerable or resistant to piercing, slashing, or whacking/blunt weapons. Being resistant to this weapon type means that the damage is halved; being vulnerable to it means that the damage is multiplied by 1.5. Some obvious examples:

• Most undead are resistant to piercing damage. Skeletons are additionally vulnerable to blunt damage.
• Thick-hided animals are resistant to slashing damage.
• “Blunt is best against hard things, slashing is best against soft things, piercing is best against fleshy things”

Some weapons’ unidentified appearances are shared with other weapons, so characters who start the game without knowledge of many weapons have to play a bit of an ID game with them. For instance, scimitar and katana could just be changed to “curved sword”. This has problems, though: it doesn’t translate very well to tiles (tiles of weapons sharing a description would have to be made identical), and it’s vulnerable to weight-ID if two weapons with different weights share the same description.

Merge the damage versus small and damage versus large stats of weapons, since they don’t really matter that much and add mostly pointless complexity. Damage should be more dependent on skill than on the size of the target monster. The only problem is how to stop the highest-damage weapons from becoming used by everyone because they’re so optimal; perhaps skill should do something drastic like add an extra die with every skill level, allowing you to have weapons that are decent at low skill (by having multiple small base dice) but poorer at high skill (because adding more small dice doesn’t work as well).

2-handed weapons can be enchanted up to +7 as normal, but one-handed weapons can only go up to +5. Alternatively, +9/+7.

War hammers are a two-handed weapon, with much higher damage than they currently have. Slashing and (maybe) piercing weapons no longer get a Str bonus to damage, only bludgeoning ones do. Probably need to rebalance weapon damage types and attribute bonuses completely.