Wizard

The wizard is one of the roles in NetHack. Wizards can be either neutral or chaotic, and can be humans, elves, gnomes or orcs. The guidebook says of them:

Wizards start out with a knowledge of magic, a selection of          magical  items,  and a particular affinity for dweomercraft. Al- though seemingly weak and easy to overcome at first sight, an ex- perienced Wizard is a deadly foe.

Wizards are relatively poor fighters with low HP and strength, but are the best spellcasters in the game. All categories of spells are unrestricted to them. They can also write unidentified scrolls and spellbooks (with a magic marker) more easily than any other class. Wizards with high intelligence are granted reduced-hunger casting. Wizards cannot use twoweapon. Wizards special spell is Magic missile, they have no bonus or penalty for emergency spells.

The wizard rank titles are: Evoker (xplvl 1-2), Conjurer (3-5), Thaumaturge (6-9), Magician (10-13), Enchanter/Enchantress (14-17), Sorcerer/Sorceress (18-21), Necromancer (22-25), Wizard (26-29), Mage (30)

Wizards can get Expert in the weapon skills of dagger, quarterstaff, and dart, as well as the attack, divination, escape, and matter spells. They can also become Skilled at Cleric, Healing, and Enchantment spells.

Intrinsics

 * Exp level 8: teleport at will if the wizard has teleportitis
 * Exp level 15: warning
 * Exp level 17: teleport control

Skills
It takes 6 skill slots to reach Expert in daggers, and 20 slots to max out all the spellcasting skills: 3x2 slots for the Skilled spells, 4x4 slots for the Expert spells, minus the 2 points already in attack and enchantment. This means that a level 30 Wizard who chooses to enhance all spellcasting skills to maximum should have 3 slots free to spend on other skills, such as unrestricted artifact weapon skills.

As part of skill slot management, a Wizard should defer enhancing any spell skill until there comes a point when doing so would provide an in-game benefit. The benefits from enhancing a spell skill are that it lowers spell failure rates, and (depending on the spell) sometimes augments the effects of a spell. When advancing spell skills, it is a good idea to check which spells you have in each school, and make sure that at least one of your spells would benefit from being enhanced, before using up the skill slot.

It is important to note that a great many spells enjoy augmented effects when advancing from Basic to Skilled (notably, fireball, cone of cold, remove curse, and detect monsters), but only two spells enjoy augmented effects when going from Skilled to Expert (namely, jumping and protection), and of these two, Wizards can only become Expert in jumping. Therefore, for spells other than escape spells, a Wizard gains no benefit from advancing to Expert unless there is a currently known high level spell (e.g. finger of death, cancellation, polymorph) whose failure rate would be lowered by such advancement.

In particular, there is almost never any need to advance divination spells to Expert, since all divination spells have the same effects at Skilled as at Expert, and none of the divination spells are of very high spell level. The skill slots saved thereby are valuable to have available for weapons, especially early in the game.

Starting equipment

 * quarterstaff
 * cloak of magic resistance
 * three random scrolls (not fire, amnesia, or blank paper)
 * two spellbooks.
 * The first is always a blessed spellbook of force bolt,
 * the other is random from the list of spellbooks level 3 and lower.
 * three random potions (not hallucination or acid)
 * two random rings (not aggravate monster, hunger, or +0 chargeable rings)
 * random wand (not wishing or nothing; wands of polymorph combined with a ring of polymorph control are also not allowed.)
 * if an Elf, random non-magical musical instrument
 * 20% chance of magic marker
 * 20% chance of blindfold

Strategy

 * Wizards should dump their quarterstaff as soon as they find any kind of non-cursed dagger unless trying for the Staff of Aesculapius via wishing.
 * They can and should reach expert in dagger. They need not enhance even their attack spell until this is done. At expert, it is possible to throw up to three daggers in a turn, so it is recommended to acquire a good number of daggers that stack together.  Wizards may find it worthwhile to make a brief sortie into the Gnomish Mines, where daggers are plentiful.  Also, daggers have a bonus to hit, which makes it easier to train with using them.  Elven daggers are especially useful.
 * Early in the game, a Wizard may find it useful to cast force bolt at a boulder, pick up the resulting stones (as many as can be carried while staying unburdened), and quiver them. Thrown stones can kill many low-level monsters before they reach the Wizard, and inflict substantial damage on those that are not killed outright.  Of course, stones should be replaced with darts, daggers, or other missiles as they become available.
 * Compared to Wizards, roles such as the Valkyrie or Barbarian are almost mono-chromatic in combat--they bash with their primary weapons and only switch tactics for special occasions. Wizards need to develop a much more diverse toolkit, since so many monsters are resistant to one or more forms of magical attack.  A fire resistant opponent may be especially vulnerable to cold attacks; an opponent with reflection can probably still be stoned by a cockatrice corpse.  The wizard player should read the wiki entries for new opponents to learn their immunities and weaknesses (so as to not waste time zapping demons with finger of death) and never be reluctant to make a tactical retreat and come back better-prepared.  Ultimately, nothing has "stab resistance," so a wizard should always  have a good physical combat option to fall back on.
 * They should sacrifice as soon as they find an altar, as their first guaranteed gift is Magicbane which is an excellent weapon, and in addition is an athame with which you can engrave Elbereth in the stone in one move, without dulling. It is also great as wielding it catches 95% of all curses, great when confronting a spellcaster. Actually at high levels and after the quest, spells are much better for attack than any weapon. So keep Magicbane wielded at all times, and use spells for attack.
 * The Wizard quest fairly easy, the Dark One is a pushover, and the reward--The Eye of the Aethiopica--is so fantastically useful that a Wizard should probably go on the quest as soon as possible. One of the many things the Eye does is vastly enhance strategic mobility through the Mazes of Menace--in particular, getting the player out of trouble in an instant.  Many Wizards set up a base camp on level 1 of Sokoban and leave most of their worldly possessions there, going back whenever they need to read a spellbook or pick up more food.  Note that adjacent monsters may follow the wizard through the Eye's magical portal, but this also has its uses--such as luring Wraiths out of a graveyard level.
 * They should try to read any non-cursed spellbook as soon as they find it. They will be warned of any chances of failure. They also have higher intelligence which makes it easy to read spellbooks. Combining the two they can start reading uncursed level 1 spellbooks at XL1.
 * If a wizard starts with a wand of polymorph, they may consider polymorphing their starting force bolt spellbook. Since it is blessed, the resulting polymorphed books will also be blessed and will automatically be readable (though not necessarily castable) to the wizard.  However, multiple polymorphing will eventually destroy the spellbook.
 * In the mid-game it is common for wizards who have the correct spells, (magic missile and create monster) to find an altar with a priest(ess) and continually create monsters and offer the high level ones to their god(dess) to increase luck, and hit points. The large number of monsters killed also means a large number of items which usually results in a few good potions, scrolls, wands and some other magical items.
 * The helm of brilliance is a favorite helmet for spellcasters, but wizards might be better off skipping it. For starters, their spellcasting failure rates are usually low enough to cast any spell they need without boosting their intelligence past 18. They will also have little need for the enhanced Power recovery, since their quest artifact gives much faster recovery anyway. Wizards are probably better off trying for the cornuthaum--it can safely be enchanted to +7, and gives the wearer clairvoyance as well as a boost to Charisma. Failing a cornuthaum, the next best choice may be an elven leather helm, which can also be enchanted to +7. Just be careful when reading a scroll of earth--boulders can take away up to 20 hit points if they fall on your head.
 * Wizards depend on spellcasting and spellbook reading, but start with no food, so they often have hunger problem in early game. Remember to always eat corpses and #pray when Weak — saving your food rations for when you cannot pray. Note that not only can wizards begin with a ring of slow digestion, they also can begin with hungerless casting as long as they have 17 or greater Intellegence.
 * Because there can be so much variation in the starting equipment, it makes them a common class for reroll scummers.

Encyclopedia entry
Ebenezum walked before me along the closest thing we could find to a path in these overgrown woods. Every few paces he would pause, so that I, burdened with a pack stuffed with arcane and heavy paraphernalia, could catch up with his wizardly strides. He, as usual, carried nothing, preferring, as he often said, to keep his hands free for quick conjuring and his mind free for the thoughts of a mage. [ A Dealing with Demons, by Craig Shaw Gardner ]