Price identification

From NetHackWiki
Jump to navigation Jump to search

Price identification is the tactic of using the price of an item to informally identify it. One can use the "buy price", the price of an item in shops, or the "sell price", the price that a shopkeeper offers when you try to sell an item. The sell price is easier to use because the buy price includes an unpredictable random factor that may disguise certain prices as other ones. Even if you have enough scrolls of identify and no conducts in mind, pricing lets you use those scrolls to prioritize the most important items.

NetHack 3.6.0 and 3.6.1 introduced changes to the price mechanics that make older price guides slightly inaccurate. The tables in § Price tables are duplicated for the 3.4.3 and 3.6.0 mechanics. If you're playing an older version and not using the tables, see the § History section before drawing conclusions based on prices.

Price derivation

Base price

Each item in NetHack has a base price, which is modified in various ways to produce the final selling price. Positively-enchanted weapons and armor have an additional 10 zm added to their base price for every point of enchantment.

Some items are considered "worthless"; you cannot sell them, but their buying price is calculated as though they had a base price of 5 zm:

Unidentified valuable gems and worthless glass are always bought as though they were valuable, and sold for only a few zorkmids, regardless of their "true" value, so price identification can't be used to distinguish them. Gray stones are priced like other items, so you can price-identify them.

Buying

When you buy an item, you are charged the base price, modified as follows. All multipliers are applied in sequence:

  • Your charisma grants a modifier to the buying price.[1]
Charisma: ≤ 5 6–7 8–10 11–15 16–17 18 ≥ 19
Buy price multiplier: 2 112 113 1 34 23 12
  • Some characters are considered "suckers", and will be charged 13 more. You are a sucker if:[2]
  • When buying unidentified objects, in 14 of cases the shopkeeper will charge 13 more. This surcharge is tied to the individual item or stack; merged stacks will inherit the higher of the two prices, while split stacks will inherit the price of the original stack.

Selling

When you sell an item, you are normally offered 12 the base price; if you're a sucker, as above, you are offered 13 the base price instead. 14 of shopkeepers will pay 14 less for unidentified objects. This modifier is consistent for a given shopkeeper, so you can determine whether a given shopkeeper is affected by selling an informally-identified item.

Further strategies

General stores are very useful for price identification because they will offer to buy all types of items. However, you can still price-identify any object (unbreakable or in a bag of holding) in any store by throwing the item into the shop from outside. If the item is fragile, you can have your pet carry it in, in a container if the item is cursed. Beware that this will relinquish ownership of the item (and the container, if any) to the shopkeeper, who will then try to sell it to you. You will need to pay the asking price or steal the item to get it back, but in a pinch, this can provide a price for an object that the shopkeeper would not normally be interested in.

Some items in an item class are 4/3 the price of other items in the class, which can give ambiguous results when buying if the random surcharge applies. A 60zm scroll of enchant weapon could appear to be one of the 80zm scrolls, a level 3 spellbook can appear to be level 4, and there are many 150zm items that can seem to be 200zm. Selling items is more reliable in this case because the random selling modifier applies to the shopkeeper; if selling an item results in what appears to be an impossible price, you know that this shopkeeper is "greedy", and all other selling prices from them can be adjusted accordingly.

Common uses

The item which is most commonly price-IDed is the scroll of identify, which is far cheaper than the other scrolls. In addition, magic lamps cost more than oil lamps, and enchanted armor costs more than their unenchanted versions.

Price-IDing can also be useful to identify bad items. The scroll of amnesia has a base price of 200zm, ten times as much as a scroll of identify. A potion of sickness has a base price of 50zm, a potion of hallucination 100zm, and a potion of blindness 150zm.

Non-Wizards will find it helpful to price-identify the difficulty level of spellbooks to determine whether they are safe to read. The base price of a spellbook is 100 zorkmids times its difficulty level. The derived sell price is half that.

Stealing powerful wands

An expensive wand (base price 500zm) is either wishing or death. In general, you should have a pet steal such an item; if you don't have a pet, both wands are well worth buying. If you have neither a pet nor the gold, either should be pretty easy to obtain: throw a tripe or food ration at a wild dog or cat, or sell junk to the shopkeeper.

One might be tempted to zap the wand (wishing for a wand of death if it's a wand of wishing) at the shopkeeper, but for early characters, this is a bad idea: the death ray might miss, which can easily lead to a quick YASD, given shopkeepers' speed and damage output. Furthermore, wishing for a wand of death from a wand of wishing is generally a waste anyways, given that by the time you really need one, you can get the one Orcus carries. If you're truly concerned about your character's ability to survive long enough to buy or steal the wand, wishing for 5000 gold pieces is a safe way to be able to do so, though it is also a waste of a wish. If you really want to kill the shopkeeper, wish for a blessed figurine of an Archon, though be aware that this has a 10% chance of backfiring.

Price tables

In the tables below, two numbers are shown in parentheses with the buying price. The first number in parentheses is the price if you are charged either the unidentified surcharge or the sucker markup. The second number is the price with both of those surcharges. For the selling price, the number in parentheses is the amount of a randomly discounted offer. Numbers in bold are prices that leave the base price ambiguous.

Magical armor

Boots

Prices in NetHack 3.4.3 and earlier
Base cost Cha ≤ 5 Cha 6–7 Cha 8–10 Cha 11–15 Cha 16–17 Cha 18 Cha ≥ 19 Selling price Boot types
8 16 (20/26) 12 (15/19) 10 (13/17) 8 (10/13) 6 (8/10) 6 (7/9) 4 (5/6) 4 (3) elven boots, kicking boots
30 60 (80/106) 45 (60/79) 40 (53/70) 30 (40/53) 23 (30/40) 20 (27/36) 15 (20/26) 15 (12) fumble boots, levitation boots
50 100 (132/176) 75 (99/132) 66 (88/117) 50 (66/88) 38 (50/66) 34 (44/59) 25 (33/44) 25 (19) jumping boots, speed boots, water walking boots
Prices in NetHack 3.6.0 and later
Base cost Cha ≤ 5 Cha 6–7 Cha 8–10 Cha 11–15 Cha 16–17 Cha 18 Cha ≥ 19 Selling price Boot types
8 16 (21/28) 12 (16/21) 11 (14/19) 8 (11/14) 6 (8/11) 5 (7/9) 4 (5/7) 4 (3) elven boots, kicking boots
30 60 (80/107) 45 (60/80) 40 (53/71) 30 (40/53) 23 (30/40) 20 (27/36) 15 (20/27) 15 (11) fumble boots, levitation boots
50 100 (133/178) 75 (100/133) 67 (89/119) 50 (67/89) 38 (50/67) 33 (44/59) 25 (33/44) 25 (19) jumping boots, speed boots, water walking boots

Fumble boots and levitation boots are both 30zm, but are of different weights. They are often cursed.

Speed boots, jumping boots, and water walking boots are all priced at 50zm. They are easily identified once worn: speed boots auto-identify if you are not already very fast (potion of speed or haste self spell), jumping boots allow you to jump, and boots of water walking are otherwise mundane.

Elven boots cause you to "walk very quietly" and self-identify if you are not already stealthy. Kicking boots are made of metal, and consequently add to spell failure percentage.

Cloaks

Prices in NetHack 3.4.3 and earlier
Base cost Cha ≤ 5 Cha 6–7 Cha 8–10 Cha 11–15 Cha 16–17 Cha 18 Cha ≥ 19 Selling price Cloak types
2 10 (12/16) 7 (9/12) 6 (8/10) 5 (6/8) 4 (5/6) 4 (4/6) 2 (3/4) 1 mummy wrapping
40 80 (106/140) 60 (79/105) 53 (70/93) 40 (53/70) 30 (40/53) 27 (36/47) 20 (26/35) 20 (15) leather, orcish ("coarse mantelet")
50 100 (132/176) 75 (99/132) 66 (88/117) 50 (66/88) 38 (50/66) 34 (44/59) 25 (33/44) 25 (19) alchemy smock ("apron"), displacement, dwarvish ("hooded cloak"), oilskin ("slippery cloak"), protection, robe ("robe")
60 120 (160/212) 90 (120/159) 80 (106/141) 60 (80/106) 45 (60/80) 40 (54/71) 30 (40/53) 30 (23) elven ("faded pall"), invisibility, magic resistance
Prices in NetHack 3.6.0 and later
Base cost Cha ≤ 5 Cha 6–7 Cha 8–10 Cha 11–15 Cha 16–17 Cha 18 Cha ≥ 19 Selling price Cloak types
2 10 (13/18) 8 (10/13) 7 (9/12) 5 (7/9) 4 (5/7) 3 (4/6) 3 (3/4) 1 (1) mummy wrapping
40 80 (107/142) 60 (80/107) 53 (71/95) 40 (53/71) 30 (40/53) 27 (36/47) 20 (27/36) 20 (15) leather, orcish ("coarse mantelet")
50 100 (133/178) 75 (100/133) 67 (89/119) 50 (67/89) 38 (50/67) 33 (44/59) 25 (33/44) 25 (19) alchemy smock ("apron"), displacement, dwarvish ("hooded cloak"), oilskin ("slippery cloak"), protection, robe ("robe")
60 120 (160/213) 90 (120/160) 80 (107/142) 60 (80/107) 45 (60/80) 40 (53/71) 30 (40/53) 30 (23) elven ("faded pall"), invisibility, magic resistance

The cloaks of displacement and protection both cost 50zm, and are the only ones at that price with a randomized appearance. If a cloak costs 60zm and has a randomized appearance, then it is either invisibility, magic resistance, or a +1 cloak of the first two types.

Other armor

All magical randomized helms (brilliance, opposite alignment, and telepathy) cost 50zm; the helmet costs 10zm.

All magical gloves (dexterity, fumbling, and power) cost 50zm; leather gloves cost 8zm.

Positive enchantment on a piece of armor increases the base price by 10zm per point of enchantment. In theory, a +2 or better pair of fumble boots might be confused for one of the much more useful 50zm boots, but the probability for positive enchantments on harmful items is too low to be worth worrying about.

Scrolls

Prices in NetHack 3.4.3 and earlier
Base cost Cha ≤ 5 Cha 6–7 Cha 8–10 Cha 11–15 Cha 16–17 Cha 18 Cha ≥ 19 Selling price Scroll types
20 40 (52/68) 30 (39/51) 26 (34/45) 20 (26/34) 15 (20/26) 14 (18/23) 10 (13/17) 10 (8) identify
50 100 (132/176) 75 (99/132) 66 (88/117) 50 (66/88) 38 (50/66) 34 (44/59) 25 (33/44) 25 (19) light
60 120 (160/212) 90 (120/159) 80 (106/141) 60 (80/106) 45 (60/80) 40 (54/71) 30 (40/53) 30 (23) blank paper ("unlabeled scroll"), enchant weapon
80 160 (212/282) 120 (159/211) 106 (141/188) 80 (106/141) 60 (80/106) 54 (71/94) 40 (53/70) 40 (30) enchant armor, remove curse
100 200 (266/354) 150 (199/265) 133 (177/236) 100 (133/177) 75 (100/133) 67 (89/118) 50 (66/88) 50 (38) confuse monster, destroy armor, fire, food detection, gold detection, magic mapping, scare monster, teleportation
200 400 (532/708) 300 (399/531) 266 (354/472) 200 (266/354) 150 (200/266) 134 (178/236) 100 (133/177) 100 (75) amnesia, create monster, earth, taming
300 600 (800/1066) 450 (600/799) 400 (533/710) 300 (400/533) 225 (300/400) 200 (267/356) 150 (200/266) 150 (113) charging, genocide, punishment, stinking cloud
Prices in NetHack 3.6.0 and later
Base cost Cha ≤ 5 Cha 6–7 Cha 8–10 Cha 11–15 Cha 16–17 Cha 18 Cha ≥ 19 Selling price Scroll types
20 40 (53/71) 30 (40/53) 27 (36/47) 20 (27/36) 15 (20/27) 13 (18/24) 10 (13/18) 10 (8) identify
50 100 (133/178) 75 (100/133) 67 (89/119) 50 (67/89) 38 (50/67) 33 (44/59) 25 (33/44) 25 (19) light
60 120 (160/213) 90 (120/160) 80 (107/142) 60 (80/107) 45 (60/80) 40 (53/71) 30 (40/53) 30 (23) blank paper ("unlabeled scroll"), enchant weapon
80 160 (213/284) 120 (160/213) 107 (142/190) 80 (107/142) 60 (80/107) 53 (71/95) 40 (53/71) 40 (30) enchant armor, remove curse
100 200 (267/356) 150 (200/267) 133 (178/237) 100 (133/178) 75 (100/133) 67 (89/119) 50 (67/89) 50 (38) confuse monster, destroy armor, fire, food detection, gold detection, magic mapping, scare monster, teleportation
200 400 (533/711) 300 (400/533) 267 (356/474) 200 (267/356) 150 (200/267) 133 (178/237) 100 (133/178) 100 (75) amnesia, create monster, earth, taming
300 600 (800/1067) 450 (600/800) 400 (533/711) 300 (400/533) 225 (300/400) 200 (267/356) 150 (200/267) 150 (113) charging, genocide, punishment, stinking cloud

If the scroll costs 20zm, 50zm, or 60zm, it is uniquely identified. Identification of more expensive scrolls usually involves using the spell or scroll of identify. If you choose to read an unknown scroll, you should always make sure the unknown scroll is not cursed, and never read it while confused.

If the scroll costs 80zm, it is either enchant armor or remove curse. Both are harmless, unless the scroll is cursed or you are confused. Before reading, you may want to bless the scroll, wear only armor you want to enchant, and hold all the cursed items you want to uncurse.

Among scrolls that cost 100zm, there are two dangerous scrolls, fire and destroy armor. Before reading, to protect from ill effects of the former, put all your scrolls, potions, and spellbooks into a container, or into a closet, or leave them on a different level, or just leave them at least 2 squares from you (but then you should beware of the danger of them being picked up by a monster if you encountered a scroll of teleportation. To protect from ill effects of both scrolls, make sure all your armor, except a shirt covered by a body armor or cloak, and body armor covered by a cloak, is something you can afford to lose.

If the scroll costs 200zm, the only dangerous scroll is amnesia, but it is really bad, and you cannot protect from it. Unless you have identified the scroll of amnesia, don't read an unkown 200-zorkmid scroll. Identify it by other means.

If the scroll costs 300zm, the only dangerous scroll is punishment. In Nethack 3.4.3, there is a simple way to get rid of the heavy iron ball, involving a pit and a boulder, but since 3.6.0, it doesn't work. Don't read the scroll unless you have non-cursed scroll of remove curse or a wand of opening, or unless you know and can cast a knock spell, or can polymorph into a nymph or metallivore. Alternatively, you can bless the scroll and then read it. Blessed scrolls of punishment are harmless, and blessed scrolls of genocide and charging are more powerful than uncursed scrolls. Finally, if you are absolutely sure it is not a scroll of genocide, you can read it while confused. Beware! Reading a scroll of genocide while confused would genocide your own race, thus killing you, even if you are wearing an amulet of life saving.

Potions

Prices in NetHack 3.4.3 and earlier
Base cost Cha ≤ 5 Cha 6–7 Cha 8–10 Cha 11–15 Cha 16–17 Cha 18 Cha ≥ 19 Selling price Potion types
0 10 (12/16) 7 (9/12) 6 (8/10) 5 (6/8) 4 (5/6) 4 (4/6) 2 (3/4) 0 water (uncursed)
50 100 (132/176) 75 (99/132) 66 (88/117) 50 (66/88) 38 (50/66) 34 (44/59) 25 (33/44) 25 (19) booze, fruit juice, see invisible, sickness
100 200 (266/354) 150 (199/265) 133 (177/236) 100 (133/177) 75 (100/133) 67 (89/118) 50 (66/88) 50 (38) confusion, extra healing, hallucination, healing, holy water ("blessed clear potion"), unholy water ("cursed clear potion"), restore ability, sleeping
150 300 (400/532) 225 (300/399) 200 (266/354) 150 (200/266) 113 (150/200) 100 (134/178) 75 (100/133) 75 (57) blindness, gain energy, invisibility, monster detection, object detection
200 400 (532/708) 300 (399/531) 266 (354/472) 200 (266/354) 150 (200/266) 134 (178/236) 100 (133/177) 100 (75) enlightenment, full healing, levitation, polymorph, speed
250 500 (666/888) 375 (499/666) 333 (444/592) 250 (333/444) 188 (250/333) 167 (222/296) 125 (166/222) 125 (94) acid, oil
300 600 (800/1066) 450 (600/799) 400 (533/710) 300 (400/533) 225 (300/400) 200 (267/356) 150 (200/266) 150 (113) gain ability, gain level, paralysis
Prices in NetHack 3.6.0 and later
Base cost Cha ≤ 5 Cha 6–7 Cha 8–10 Cha 11–15 Cha 16–17 Cha 18 Cha ≥ 19 Selling price Potion types
0 10 (13/18) 8 (10/13) 7 (9/12) 5 (7/9) 4 (5/7) 3 (4/6) 3 (3/4) 0 (0) water (uncursed)
50 100 (133/178) 75 (100/133) 67 (89/119) 50 (67/89) 38 (50/67) 33 (44/59) 25 (33/44) 25 (19) booze, fruit juice, see invisible, sickness
100 200 (267/356) 150 (200/267) 133 (178/237) 100 (133/178) 75 (100/133) 67 (89/119) 50 (67/89) 50 (38) confusion, extra healing, hallucination, healing, holy water ("blessed clear potion"), unholy water ("cursed clear potion"), restore ability, sleeping
150 300 (400/533) 225 (300/400) 200 (267/356) 150 (200/267) 113 (150/200) 100 (133/178) 75 (100/133) 75 (56) blindness, gain energy, invisibility, monster detection, object detection
200 400 (533/711) 300 (400/533) 267 (356/474) 200 (267/356) 150 (200/267) 133 (178/237) 100 (133/178) 100 (75) enlightenment, full healing, levitation, polymorph, speed
250 500 (667/889) 375 (500/667) 333 (444/593) 250 (333/444) 188 (250/333) 167 (222/296) 125 (167/222) 125 (94) acid, oil
300 600 (800/1067) 450 (600/800) 400 (533/711) 300 (400/533) 225 (300/400) 200 (267/356) 150 (200/267) 150 (113) gain ability, gain level, paralysis

If the potion is water (clear potion), price gives some information about its beatitude. If the price is 0, the water is uncursed; otherwise it is either holy or unholy water.

If the price is 250zm, you can ensure it is not cursed, then try to apply it. If it is a potion of oil, it will be lit. Do not do this when the potion is owned by a shop, or you will be forced to pay for the potion and will be charged Yendorian Fuel Tax.

Otherwise, price identification of a potion usually includes quaffing it. See Potion § Price identification then quaffing for more information.

Rings

Prices in NetHack 3.4.3 and earlier
Base cost Cha ≤ 5 Cha 6–7 Cha 8–10 Cha 11–15 Cha 16–17 Cha 18 Cha ≥ 19 Selling price Ring types
100 200 (266/354) 150 (199/265) 133 (177/236) 100 (133/177) 75 (100/133) 67 (89/118) 50 (66/88) 50 (38) adornment, hunger*, protection, protection from shape changers, stealth, sustain ability, warning
150 300 (400/532) 225 (300/399) 200 (266/354) 150 (200/266) 113 (150/200) 100 (134/178) 75 (100/133) 75 (57) aggravate monster*, cold resistance, gain constitution, gain strength, increase accuracy, increase damage, invisibility, poison resistance, see invisible, shock resistance
200 400 (532/708) 300 (399/531) 266 (354/472) 200 (266/354) 150 (200/266) 134 (178/236) 100 (133/177) 100 (75) fire resistance, free action, levitation, regeneration, searching, slow digestion, teleportation*
300 600 (800/1066) 450 (600/799) 400 (533/710) 300 (400/533) 225 (300/400) 200 (267/356) 150 (200/266) 150 (113) conflict, polymorph*, polymorph control, teleport control
Prices in NetHack 3.6.0 and later
Base cost Cha ≤ 5 Cha 6–7 Cha 8–10 Cha 11–15 Cha 16–17 Cha 18 Cha ≥ 19 Selling price Ring types
100 200 (267/356) 150 (200/267) 133 (178/237) 100 (133/178) 75 (100/133) 67 (89/119) 50 (67/89) 50 (38) adornment, hunger*, protection, protection from shape changers, stealth, sustain ability, warning
150 300 (400/533) 225 (300/400) 200 (267/356) 150 (200/267) 113 (150/200) 100 (133/178) 75 (100/133) 75 (56) aggravate monster*, cold resistance, gain constitution, gain strength, increase accuracy, increase damage, invisibility, poison resistance, see invisible, shock resistance
200 400 (533/711) 300 (400/533) 267 (356/474) 200 (267/356) 150 (200/267) 133 (178/237) 100 (133/178) 100 (75) fire resistance, free action, levitation, regeneration, searching, slow digestion, teleportation*
300 600 (800/1067) 450 (600/800) 400 (533/711) 300 (400/533) 225 (300/400) 200 (267/356) 150 (200/267) 150 (113) conflict, polymorph*, polymorph control, teleport control

An asterisk (*) indicates that this ring is generated cursed 90% of the time.

The most useful rings to price-identify are the most expensive and most powerful rings: the 200zm and 300zm rings.

All 200zm rings, provided they are non-cursed, are useful and safe to wear. These include the rings of free action, slow digestion, searching, levitation, regeneration, fire resistance and teleportation. It is important to only wear rings from this group known to be non-cursed, since uncontrolled teleportitis or a cursed ring of levitation may be hazardous. The ring of levitation auto-identifies when worn; the effects of the other 200zm rings, with the probable exceptions of fire resistance or teleportation if you already have the intrinsics, will eventually become clear if you wear the rings. The ring of regeneration can also be quickly tested for: wear it, throw a (preferably non-breakable) object up to lose a few hit points, and watch if you re-gain them every turn.

The 300zm rings include the rings of conflict, teleport control, polymorph, and polymorph control. The first two are among the most coveted items in the game and are frequent wish targets, however the ring of polymorph means that 300zm rings are not generally safe to wear. Conflict can still be easily identified by wearing it for a turn or two around a peaceful monster (remember that a shopkeeper, aligned priest, or your Quest leader are probably not wise choices). Teleport control can also be identified by putting on the ring and triggering a teleport (via trap, scroll, wand, etc.) If your 300zm ring is neither of these, do not wear it; use a scroll, spell, a handy sink or a source of enlightenment to reliably identify the other 300zm rings. Alternately, a riskier method of determining whether a 300zm ring is safe to wear is simply to wear it for a few hundred turns without wearing a shirt, cloak, or body armor (or wearing junk armor); that way, if you polymorph you will not break your useful armor.

Wands

Prices in NetHack 3.4.3 and earlier
Base cost Cha ≤ 5 Cha 6–7 Cha 8–10 Cha 11–15 Cha 16–17 Cha 18 Cha ≥ 19 Selling price Wand types
100 200 (266/354) 150 (199/265) 133 (177/236) 100 (133/177) 75 (100/133) 67 (89/118) 50 (66/88) 50 (38) light, nothing
150 300 (400/532) 225 (300/399) 200 (266/354) 150 (200/266) 113 (150/200) 100 (134/178) 75 (100/133) 75 (57) digging, enlightenment, locking, magic missile, make invisible, opening, probing, secret door detection, slow monster, speed monster, striking, undead turning
175 350 (466/620) 262 (349/465) 233 (310/413) 175 (233/310) 132 (175/233) 117 (156/207) 87 (116/155) 87 (66) cold, fire, lightning, sleep
200 400 (532/708) 300 (399/531) 266 (356/472) 200 (266/354) 150 (200/266) 134 (178/236) 100 (133/177) 100 (75) cancellation, create monster, polymorph, teleportation
500 1000 (1332/1776) 750 (999/1332) 666 (888/1184) 500 (666/888) 375 (500/666) 334 (444/592) 250 (333/444) 250 (188) death, wishing
Prices in NetHack 3.6.0 and later
Base cost Cha ≤ 5 Cha 6–7 Cha 8–10 Cha 11–15 Cha 16–17 Cha 18 Cha ≥ 19 Selling price Wand types
100 200 (267/356) 150 (200/267) 133 (178/237) 100 (133/178) 75 (100/133) 67 (89/119) 50 (67/89) 50 (38) light, nothing
150 300 (400/533) 225 (300/400) 200 (267/356) 150 (200/267) 113 (150/200) 100 (133/178) 75 (100/133) 75 (56) digging, enlightenment, locking, magic missile, make invisible, opening, probing, secret door detection, slow monster, speed monster, striking, undead turning
175 350 (467/622) 263 (350/467) 233 (311/415) 175 (233/311) 131 (175/233) 117 (156/207) 88 (117/156) 88 (66) cold, fire, lightning, sleep
200 400 (533/711) 300 (400/533) 267 (356/474) 200 (267/356) 150 (200/267) 133 (178/237) 100 (133/178) 100 (75) cancellation, create monster, polymorph, teleportation
500 1000 (1333/1778) 750 (1000/1333) 667 (889/1185) 500 (667/889) 375 (500/667) 333 (444/593) 250 (333/444) 250 (188) death, wishing

It is usually better to engrave ID wands to determine their identity, however base 175zm wands found in shops are all useful (cold, sleep, fire, or lightning), price identification can distinguish a wand of sleep from a wand of death without using another charge, any wand that makes engravings vanish that has a base price of 150zm is a wand of make invisible, and any wand that gives no message when engraved with a base price of 100zm is a wand of nothing.

Spellbooks

Prices in NetHack 3.6.0 and later
Base cost Cha ≤ 5 Cha 6–7 Cha 8–10 Cha 11–15 Cha 16–17 Cha 18 Cha ≥ 19 Selling price Spellbook types
100 200 (267/356) 150 (200/267) 133 (178/237) 100 (133/178) 75 (100/133) 67 (89/119) 50 (67/89) 50 (38) Level 1 books: force bolt, protection, detect monsters, light, sleep, jumping, healing, knock
200 400 (533/711) 300 (400/533) 267 (356/474) 200 (267/356) 150 (200/267) 133 (178/237) 100 (133/178) 100 (75) Level 2 books: magic missile, drain life, create monster, detect food, confuse monster, slow monster, cure blindness, wizard lock
300 600 (800/1067) 450 (600/800) 400 (533/711) 300 (400/533) 225 (300/400) 200 (267/356) 150 (200/267) 150 (113) Level 3 books: remove curse, clairvoyance, detect unseen, identify, cause fear, charm monster, haste self, cure sickness, extra healing, stone to flesh
400 800 (1067/1422) 600 (800/1067) 533 (711/948) 400 (533/711) 300 (400/533) 267 (356/474) 200 (267/356) 200 (150) Level 4 books: cone of cold, fireball, detect treasure, invisibility, levitation, restore ability
500 1000 (1333/1778) 750 (1000/1333) 667 (889/1185) 500 (667/889) 375 (500/667) 333 (444/593) 250 (333/444) 250 (188) Level 5 books: magic mapping, dig
600 1200 (1600/2133) 900 (1200/1600) 800 (1067/1422) 600 (800/1067) 450 (600/800) 400 (533/711) 300 (400/533) 300 (225) Level 6 books: create familiar, turn undead, teleport away, polymorph
700 1400 (1867/2489) 1050 (1400/1867) 933 (1244/1659) 700 (933/1244) 525 (700/933) 467 (622/830) 350 (467/622) 350 (263) Level 7 books: finger of death, cancellation

Determining the level of a spellbook can be very useful for spellcasters, since it can eliminate books that are much too high level to be read, and reveal books that should be easy to read. However, knowing the level of a spellbook is not very helpful unless the book is also BUC identified.

Amulets

All amulets cost 150zm and weigh 20, so they cannot be distinguished using price identification.

Variants

SLASH'EM

Price identification is more complicated in SLASH'EM, partly due to the addition of several new items, and partly due to discriminatory role-based markups:

  • Barbarians pay triple the base price ("Barbarians are gullible")
  • Rogues pay double the base price ("Rogues are untrustworthy")
  • Samurai pay double the base price ("Samurai are from out of town")

Furthermore, in the black market, magical items cost 50 times the base price, and nonmagical items cost 25 times the base price. These markups are applied in this order, after any relevant unidentified item surcharge, sucker markup, and charisma modifier.

Relevant parts of above tables that change are given in the table below.

Prices in SLASH'EM
Category Base cost Cha ≤ 5 Cha 6–7 Cha 8–10 Cha 11–15 Cha 16–17 Cha 18 Cha ≥ 19 Selling price Item types
Rings 100 200 (266/354) 150 (199/265) 133 (177/236) 100 (133/177) 75 (100/133) 67 (89/118) 50 (66/88) 50 (38) adornment, hunger*, mood, protection, protection from shape changers, sleeping* stealth, sustain ability, warning
150 300 (400/532) 225 (300/399) 200 (266/354) 150 (200/266) 113 (150/200) 100 (134/178) 75 (100/133) 75 (57) aggravate monster*, cold resistance, gain constitution, gain dexterity, gain intelligence, gain strength, gain wisdom, increase accuracy, increase damage, invisibility, poison resistance, see invisible, shock resistance
Wands 150 300 (400/532) 225 (300/399) 200 (266/354) 150 (200/266) 113 (150/200) 100 (134/178) 75 (100/133) 75 (57) digging, enlightenment, healing, locking, magic missile, make invisible, opening, probing, secret door detection, slow monster, speed monster, striking, undead turning
175 350 (466/620) 262 (349/465) 233 (310/413) 175 (233/310) 132 (175/233) 117 (156/207) 87 (116/155) 87 (66) cold, draining, fire, lightning, sleep
200 400 (532/708) 300 (399/531) 266 (354/472) 200 (266/354) 150 (200/266) 134 (178/236) 100 (133/177) 100 (75) cancellation, create monster, fear, polymorph, teleportation
300 600 (800/1066) 450 (600/799) 400 (533/710) 300 (400/533) 225 (300/400) 200 (267/356) 150 (200/266) 150 (113) create horde, extra healing, fireball
Potions 50 100 (132/176) 75 (99/132) 66 (88/117) 50 (66/88) 38 (50/66) 34 (44/59) 25 (33/44) 25 (19) blood ("blood-red potion"), booze, fruit juice, see invisible, sickness
100 200 (266/354) 150 (199/265) 133 (177/236) 100 (133/177) 75 (100/133) 67 (89/118) 50 (66/88) 50 (38) amnesia ("sparkling potion"), clairvoyance, confusion, extra healing, hallucination, healing, holy water ("blessed clear potion"), unholy water ("cursed clear potion"), restore ability, sleeping
150 300 (400/532) 225 (300/399) 200 (266/354) 150 (200/266) 113 (150/200) 100 (134/178) 75 (100/133) 75 (57) blindness, ESP, gain energy, invisibility, monster detection, object detection
300 600 (800/1066) 450 (600/799) 400 (533/710) 300 (400/533) 225 (300/400) 200 (267/356) 150 (200/266) 150 (113) gain ability, gain level, invulnerability, paralysis
350 700 (932/1242) 525 (699/931) 466 (621/828) 350 (466/621) 263 (350/466) 234 (311/414) 175 (233/310) 175 (132) vampire blood ("blood-red potion")
Robes 25 50 (66/88) 37 (49/66) 33 (44/58) 25 (33/44) 19 (25/33) 17 (22/30) 12 (16/22) 12 (9) robe
50 100 (132/176) 75 (99/132) 66 (88/117) 50 (66/88) 38 (50/66) 34 (44/59) 25 (33/44) 25 (19) power, protection, weakness
Cloaks 40 80 (106/140) 60 (79/105) 53 (70/93) 40 (53/70) 30 (40/53) 27 (36/47) 20 (26/35) 20 (15) leather, orcish ("coarse mantelet"), poisonous
60 120 (160/212) 90 (120/159) 80 (106/141) 60 (80/106) 45 (60/80) 40 (54/71) 30 (40/53) 30 (23) elven ("faded pall"), invisibility, lab coat ("white coat"), magic resistance

UnNetHack

In UnNetHack, the random 25% reduction of selling price applied to the whole shop. That means if an item sells 38 of its base price, that shopkeeper will pay 25% less for everything you sell there.

GruntHack

In GruntHack, shopkeepers that hate your race increase the buy price of every item by 33% (multiplying by 43), and cut the sell price of every item by 66% (dividing by 3).

Also, the base price of any item is increased if it has object properties: by 100 for one property, 500 for two properties, 1000 for three properties, and so on.

FIQHack

In FIQHack, all items in shops are automatically identified for tourists. This includes items that you sell to shopkeepers.

History

In NetHack 3.4.3, the random modifiers for unidentified items also applied to identified items; all surcharges and price reductions are also applied sequentially, using integer arithmetic. For example, if a character with charisma 7 buying an item with base price of 100 is charged an unidentified surcharge, the shopkeeper's price is calculated as follows:

  • 100 base price
  • 43 unidentified surcharge multiplier = 100 × 43 = 133
  • 32 charisma multiplier = 133 × 32 = 199

In 3.6.* versions, the calculation accumulates integer multipliers and divisors for all adjustments, then applies these once at the end to get the effective price. Thus for the same example, the calculation will be:

  • (43) × (32) = 126
  • 100 × 126 = 200

This sometimes results in prices 1 to 2 zorkmids higher or lower than would be obtained in previous versions. The stated intention of this change is to make price identification harder by ensuring that the price of items marked up twice more often equals another base price, e.g. 200zm instead of 199zm. Another consequence of this method is that the order in which adjustments are applied no longer matters.

Before NetHack 3.6.1, the random modifier for selling unidentified items was determined per-sale, not per-shopkeeper. By repeatedly dropping the item, declining the sale, and picking it up again, you'd eventually get two different quotes, the higher of which was the correct one.

References

External links

Various external tools exist for the purpose of aiding in price IDing:

  • Clippy
  • Determine Objects by their Price, which is more accurate due to taking some more corner cases into account, but less broad because it only works magical items and excludes weapons, armor, tools, and gems.
  • Consolidated item tables on alt.org, which are 3.4.3-specific and lists the base price of every single item (which has not changed since)
  • NetHack Shopping Spoiler, another 3.4.3-specific resource mirrored on alt.org
  • DizzyPrice via archive.org, an open-source price ID tool updated to the new rounding method for the NetHack 3.6.0 series.
  • #annotate at NetHackathon, a companion app that contains a price ID tool and several other note-taking features