nethack spoiler site http://www.nethack.de/ Maintainer: Sascha Wostmann (sascha@nethack.de) ----------------------------------------------------------------- Spell Failure version 1.1 by Kevin Hugo Starting in Nethack 3.2.0, shields and metallic armor began to hinder spellcasting. Many characters would have 100% spell failure even for low-level spells. The solution is simple: take off the troublesome armor before spellcasting. This spoiler file further explains the factors accounted for in spell failure. What causes spells to fail? ~~~~~~~~~~~~~~~~~~~~~~~~~~~ - Your armor. Metallic body armor, metallic helmets (except helm of brilliance), metallic gloves, metallic shoes, and any shield (although a small shield is not as bad) will penalize you. Fighter-type classes are not penalized as much as the other classes. The following items are "safe" for spellcasting: All shirts All dragon scales and dragon scale mails Leather jacket, leather armor, studded leather armor Crystal plate mail All cloaks Elven leather helm, fedora, helm of brilliance Cornathaum (wizards only) All gloves except gauntlets of power All boots except iron boots So the "best" armor class you could achieve for spellcasting -- not including your intrinsic protection or item enchantments -- is with any shirt, any dragon scale mail, a clock of protection, a helm of brilliance, gauntlets of dexterity, and high boots. Of course, there are other combinations that yield a lower AC or spellcasting ability but have strategic advantages. - The level of the spell, as follows: 1 Detect monsters, force bolt, healing, knock, light, sleep. 2 Confuse monster, create monster, cure blindness, detect food, magic missle, wizard lock. 3 Cause fear, charm monster, clairvoyance, cure sickness, detect unseen, extra healing, hasten self. 4 Detect treasure, fireball, invisibility, levitation, restore ability. 5 Cone of cold, dig, identify, magic mapping, remove curse. 6 Create familiar, polymorph, teleport away, turn undead. 7 Cancellation, finger of death. What improves spellcasting success? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + Your class. Each class has its own base ability, armor penalties, bonuses for emergency spells, and a spell that they are especially good at. See the table below. + Your intelligence (ABCERSTW) or wisdom (HKPV). + Your experience level. + Certain "emergency" spells get an extra bonus. They are healing, extra healing, cure blindness, cure sickness, restore ability, and remove curse. The amount of the bonus depends on your class. Note that the tourist is actually penalized for these spells. + If you have the teleport intrinsic, teleport will always work at random intervals or when you fall into water. How is the spell failure calculated? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ We first calculate the variable "splcaster," which is the sum of the following items (marked with #). An increasing total is worse for spellcasting, and is limited to a maximum of 20. # The "Base" value from the table below, depending on the character's class. # If an "emergency" spell, the "Emerg" field. # If wearing any shield, the amount in the "Shield" field. # If wearing metallic body armor, the amount in the "Suit" field. # If wearing metallic helmets other than the helm of brilliance, add 4 (metal helmets interfere with the mind). # Metallic gloves add 6 (casting channels through the hands). # Metallic boots add 2 (all metal interferes to some degree). # Add -4 if the spell is special to that class (see table). Class Base Emerg Shield Suit Stat Special Spell ~~~~~ ~~~~ ~~~~~ ~~~~~~ ~~~~ ~~~~ ~~~~~~~~~~~~~ A 5# 0# 2# 10# Int Magic mapping B 14# 0# 0# 8# Int Haste self C 12# 0# 1# 8# Int Dig E 5# 0# 1# 10# Int Detect unseen H 3# -3# 2# 10# Wis Cure sickness K 8# -2# 0# 9# Wis Turn undead P 3# -2# 2# 10# Wis Remove curse R 8# 0# 1# 9# Int Detect treasure S 10# 0# 0# 8# Int Clairvoyance T 5# 1# 2# 10# Int Charm monster V 10# -2# 0# 9# Wis Cone of cold W 1# 0# 3# 10# Int Magic missle Next, we calculate a base chance of success, which is 5.5 times your intelligence or wisdom, depending on your class. Now, you need to gain 4 experience levels for each spell level; your chance will be reduced by 7 times the square of this difference if you haven't, and increased with diminishing returns if you have. The result is clipped to the range of 0% to 120% success. If you are wearing a shield larger than a small shield, the chance is reduced to 1/4 its amount (except if it is your class' special spell -- then it is only halved). Finally, the chance of success is adjusted by the variable splcaster by the following formula: chance = (chance * (20-splcaster) / 15) - splcaster The result is clipped to the range of 0% to 100% success. With suggestions by Sascha Wostmann and Petrosky .