Have Zeus’s lightning bolts as an item or artifact you can throw. If an artifact weapon, it should automatically return like Mjollnir; otherwise, it could be an item that vanishes after striking a target but deals immense shock damage to that target.
Dipping ammo in various potions can endow it with a permanent object property related to the potion.
Ammo shot from launchers (but not thrown ones) should receive a damage bonus based either on Dexterity or on the launcher’s enchantment to compensate for the Strength-based damage bonus for thrown missiles or melee weapons.
Spell of collect arrows: it magically retrieves all objects on the current level that you’ve thrown or fired at some point in the past. (Possibly limited to weapon class objects).
Fireable ammo (that which is only capable of being used by launchers) cannot be enchanted. It instead uses the enchantment of its launcher as the enchantment.
In variants where your god can gift non-artifacts, they should sometimes gift you a stack of projectiles (ideally they can match it to some ranged weapon you have if they are feeling nice). It would be useful even when the player already has a favored melee weapon.
Carrying a loadstone makes all stone-type missiles (slung ammo, etc) deal double damage - increasing the payload of stones. Also, when blessed or uncursed, it doesn’t weigh as much as cursed.
Artifact bow that acts like an infinity bow in Minecraft: if you have bow-compatible ammo in your quiver, it shoots a phantom copy of that ammo (never multishotting) without using up the real ammo. When this phantom missile hits the floor, it disappears.
Snow golem, which is a ’ monster found in icy locales. Does not generate in Gehennom. It uses a spitting attack to launch snowballs (flavored as throwing them), which are an object which behaves like spat venom in that they disappear one way or another at the end of their flight. These deal damage and possibly knockback. The encyclopedia entry for snow golems uses “Frosty the Snowman” as reference material.
Invoking the Longbow of Diana gives you light arrows. These are a special object, weightless, created with the same enchantment as the Longbow, but attempting to enchant them further will fail (maybe making the enchanted arrows evaporate). If they leave your inventory for any reason, they will vanish. As a weapon, they are very powerful (to the point of probably instakilling most weaker monsters they hit). To prevent the player stockpiling them, the invoke effect will only top up the amount of them in your inventory to 5.
When a light arrow strikes a target or falls to the ground (and vanishes in the process), it permanently lights up the surrounding area.
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.
The closer someone is to iron bars when attempting to shoot ammo through them, the lower the chance is of it hitting the bars.
Disallow quivering things that can’t be used as missiles (and therefore have no business being in the quiver).
Bodkin arrows that have heavyshot (from DynaHack): instead of multishooting, they deal double or triple damage depending on how many you would have multishot otherwise.
Characters with at least Basic in sling can do something (use a touchstone? flint stone? any gray stone?) to break rocks into slingshot, which weigh 1 and have comparable to-hit and damage to flint stones. Slingshot may be weapon-class instead of rock-class. The higher the sling skill, the more shot that one can get out of a single rock. There should also be rare silver rocks, which can be broken into silver shot.
Monsters will only pick up projectile ammo if they are carrying an appropriate launcher; they will otherwise ignore it. (This does not apply to darts and daggers and other non-launcher missiles.)
“Homing” object property, which generates on ammo and guarantees a hit.
When you throw ammo without the proper launcher, the game makes it clear that you’re doing it wrong, e.g. “You clumsily throw the arrow”. This also abuses Wisdom.
Poisonous tree frogs, which only generate in trees. Applying darts or arrows to them can coat the darts or arrows with poison, but the poison can also get on your hands.
Type of arrow that is made out of enchanted worm teeth. Gives the racial arrow bonus to anyone using it.
Resolve the problem of having to double-enchant launchers and ammo and get double bonuses in one of two ways:
The Oracle centaur statues may contain sizeable piles of ranged ammunition, particularly arrows and crossbow bolts.
The game should ask to confirm when you try to throw something that is not intended to be thrown (for example, if you unwielded your bow and are now trying to throw arrows).
