Storm

ArrowStorm, DaggerStorm, or SilverStorm are the use of missile weapons as the primary way to deal damage in NetHack.

The preferred roles to do this are Rogues and Rangers, for their weapon proficiency and for their +1 multishot bonus, but roles with high skill in missile weapons also work (particularly Wizards and Valkyries for Expert daggers).

DaggerStorm
As a Ranger or a Rogue you get +1 multishot for thrown daggers, even when dagger is Unskilled, so, even as an early-game character, you can probably deal more damage by throwing daggers than by using a melee weapon, even in melee range.

The best type of daggers to do this is probably the silver dagger, due to his high damage bonus (+1d20) against the silver-hating monsters, but since they are hard to find, most people end up using a stack of elven daggers or just plain normal daggers.

Rogues also get a backstab bonus (+1dXL) against fleeing monsters, for each thrown dagger; in the end game, the damage of a stack of thrown, enchanted silver daggers against a fleeing silver-hating undead, assuming that every projectile hits and the character has maximum strength, as a level 30 Rogue with Expert dagger skill: 2      skill bonus +6      strength bonus +2.5    average of 1d4 against small monsters, becomes 1d3 (2) against large +7      enchantment +10.5   average of 1d20 silver damage against silver-haters +2.5    average of 1d4 blessed damage against undead +15.5   average of 1d30 backstab damage against fleeing monsters =45.5   average for a single blessed +7 silver dagger against a fleeing small silver-hating undead *2.5    1d4 daggers thrown in a single firing =113.75 *average* final damage (112.5 against large, absolute best case is 292! damage) Compare this to the average damage for Grayswandir, the best weapon in the game, twoweaponing it with another silver saber, with maxed skills (assuming, with the same Rogue, Expert two-weapon combat and Skilled saber): 2*(     Grayswandir's double damage  4.5     average of 1d8 against any +7       enchantment ) +6      strength bonus +10.5   average of 1d20 silver damage against silver-haters +2.5    average of 1d4 blessed damage against undead + 4.5     average of 1d8 against any +7      enchantment +6      strength bonus +10.5   average of 1d20 silver damage against silver-haters +2.5    average of 1d4 blessed damage against undead =72.5   average of the blessed +7 Grayswandir twoweapon with a blessed +7 silver saber against a silver-hating undead That said, a stack of silver dagger is one of the rarest item in the Mazes of Menace (stacks of 1d6 silver daggers are 0.3% of all the randomly-generated items), so most adventurers will settle for a stack of daggers, or elven daggers when possible, but even in that case, it's usually enough to kill most monsters before they even have a chance of landing a hit on you, since daggers are a ranged attacks, with the range depending purely on your strength (with St:25 you have 10 squares of range).

Unless you're using silver daggers, if there are spare scrolls of enchant weapon laying around, it's better to Fooproof your stack of enchanted daggers, since a lot of monsters can corrode iron, limiting your damage; it's also better to #name your stack of daggers giving it a unique name, and to set an autopickup exception for your own daggers, to help picking them up. Also, watch out when firing around water, since daggers that end up in a pool or a moat are hard to recover; better have a backup melee weapon for sea monsters.

One of the advantages of throwing daggers, as opposed to using a melee weapon, is the fact that you can use a wielded artifact weapon for the bonus it provides, and not just for the damage; Magicbane's damage is low, compared to other artifacts, but the perks it gives (MR and curse absorbing) are nice; Magicbane is a great weapon, even for Rogues (chaotics) because it also gives you a way to engrave a semipermanent Elbereth - great for the backstab bonus. Another way to scare monsters, that works at range, is a tooled horn, which is another great tool for Rogues.