Armour, its erosion and enchantment, and magic cancellation in NetHack 3.4

armr-340.html Last edited 2002-06-19 for NetHack 3.4.0
Compiled for 3.2.2 by Kevin Hugo.
Updated for 3.4.0 by Dylan O'Donnell <psmith@spod-central.org>.
Converted to HTML by Kate Nepveu <knepveu@steelypips.org>.

Contents

• Table of armor
• Armor erosion and enchantment
• Magic cancellation

Armor is listed above by category, then by increasing armor class, and finally by increasing price. Alternative Japanese names for items are given in parentheses (). The COST field denotes the base price of each item. WGT specifies the weight (100 zorkmids weighs 1).

Armor comprises 10% of all randomly-generated items in the main dungeon, 0% in containers, 12% on the Rogue level, and 20% in hell. PR is the relative probability of each subtype; the suffix specifies the chance of blessed/cursed:

Initial enchantment depends on whether the item was blessed or cursed, and is exponentially distributed. Armor is never generated erodeproof except for: splint mail at the start of the game for a Samurai, or on the Samurai Quest; as equipment for certain monsters; and sometimes in Rogue level bones piles. Dragon armor is sometimes randomly generated for player-like monsters on the Astral Plane, but is otherwise never randomly generated.

The base amount that your armor class is reduced (disregarding enchantment or damage) is shown in the AC field. The material of each piece of armor, described by M, affects whether the item can be damaged. In addition, metallic armor can increase your spell failure rate, and iron helmets protect from falling rock traps. The materials are as follows:

Some armors have EFFECTS. The number of hash signs (#) in this column describes the degree of magic cancellation (see below). Other effects are also possible:

      Knights without boots    Anyone with boots
         ~~~~~~~~~~~~~~~~~~~~~    ~~~~~~~~~~~~~~~~~
                                     X
             X.X                   XXXXX
            X...X                  XXXXX
            ..@..                 XXX@XXX
            X...X                  XXXXX
             X.X                   XXXXX
                                     X

Finally, some types of armor have a different APPEARANCE when unidentified. Those listed with an asterisk (*) are randomized within their armor category. Boots with the appearance "snow boots" make ice act like normal terrain (but the Fumble armor property still happens at its normal rate). Gloves and boots with the appearance "riding gloves" and "riding boots" give a (non-cumulative) bonus to the chance of successfully saddling a steed. Helmets with the appearance "visored helmet" provide defence against the blinding attack of ravens and the spitting attack of cobras.

Armor erosion and enchantment

(Adapted from the spoiler "enchant.lim" by Peter Snelling and Boudewijn Waijers.)

Your armor class is reduced by the base amount shown above. However, if armor is damaged, that amount of reduction is lowered by the greatest degree of erosion (damaged = 1, very damaged = 2, and thoroughly damaged = 3), but that will not lower the AC reduction beyond zero. The armor's material determines what types of attacks can cause damage (see above).

There are several ways to prevent erosion. Samurai, Angels, "player" monsters, lawful demons, and Roguelike bones piles may be generated with erodeproof armor. Specify "erodeproof","rustproof", "corrodeproof", "fireproof", or "rotproof" when wishing for an armor (any of these will do, and will be ignored if not applicable). You can temporarily prevent rust and corrosion damage by (a)pplying grease to your armor from a can of grease. An item can also be permanently erodeproofed by reading a non-cursed scroll of enchant armor while confused (also removes damage) or a cursed scroll of destroy armor while confused (does not remove damage).

Your AC is then further reduced by the enchantment (e.g., +1) of the armor. The enchantment may be changed by reading scrolls of enchant armor while wearing the armor. One piece of worn armor is randomly selected, so you should remove armor you don't want enchanted. A blessed scroll may add several enchantments, an uncursed scroll adds one enchantment, and a cursed scroll removes one enchantment. Other effects are possible -- notably, dragon scales can be converted to dragon scale mail -- please refer to the spoiler "scrl-340.html". The enchantment of armor may also be affected by wands or spells of cancellation, spell of drain life if not currently in inventory, or by a disenchanter's special attack.

If armor is enchanted above +3 (+5 for cornuthaums if you are a Wizard or for elven armor), then there is a chance of it being destroyed if it is enchanted further. Thus, the maximum safe enchantment is +5 (+7). This is obtained by reading uncursed or blessed scrolls until +3 (+5) is reached, and then reading a blessed scroll. If by chance this results in +4 (+6), you could bring the enchantment back down to +3 (+5) -- by reading a cursed scroll of enchant armor -- before trying again.

Magic cancellation

(Adapted from the spoiler "protect", by Peter Snelling, Boudewijn Waijers, and Michal Pawlak.)

Magic cancellation affects the chance of success of the following special melee attacks: fire, cold, electricity, sleep, poison, paralysis, level drain, "sticking to" ("You cannot escape from the mimic!" -- but not grab-attacks by, for example, owlbears or krakens), lycanthropy, teleport, intrinsic speed stealing (shades and skeletons), energy drain, slime and disenchanting. Note that it does NOT affect the success probability of ray attacks, nor does it help against "defensive attacks" (like a floating eye's paralysis).

The chances of any one of the above special attacks succeeding are calculated in the following way:

• The attack must first hit (i.e. pass your AC). You take the associated physical damage (if any) if the hit is successful and you are not resistant to that type of attack.
• Some of the attacks succeed only sometimes anyway:
  • 1/3 Drain level and paralysis
  • 1/4 Lycanthropy, steal speed and drain energy
  • 1/5 Sleep
  • 1/8 Poison
• The attack must finally pass the cancellation test. The probability of this depends on the greatest cancellation factor (the number of #s above) among all your armor:

  None	150/150 (100%)
  #	101/150 (~67%)
  ##	52/150 (~35%)
  ###	3/150 (2%)
  Monster cancelled	0/150 (0%)

If all the above tests have been passed, then you suffer the effect of the special attack. For example: if you are wearing a gray dragon scale mail, and are attacked by a vampire, then 1/3 of his successful bites will end in you losing a level. If you however wear a lowly orcish cloak over your armour (MC=2), the probability will immediately drop to about 1/9 (1/3 * 52/150) and an oilskin cloak will reduce the probability to below 1%.

Note that the magical cancellation is different from intrinsic resistances for fire/cold/electricity attacks. If you are hit by a fire attack while fire resistant you get no physical damage, but there's still a chance of losing your scrolls/spellbooks/potions. If you are protected from a fire attack by cancellation, the attack fails and your equipment is safe.

Incidentally, if you wondered about the similarity between the name of this property ("magic cancellation") and the name of a certain wand and spell -- it is no accident. Zapping the attacker with the wand/spell of cancellation makes the last test always fail and you will never suffer from special attacks by this creature.

Do NOT confuse this property with magic resistance, which is obtained by something entirely different; see the spoiler drgn-340.html.

Acknowledgements

Thanks to Bruce Cox for proofreading the original version of this file.
Further corrections and clarifications provided by Mitch Gold, Pat Rankin, Adrian Rowley, Warrendy, and Sascha Wostmann.

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