Magicbane
) Magicbane  

Base item  athame 
Damage vs. small  1d4 + 1d4 + (special) (28) 
Damage vs. large  1d3 + 1d4 + (special) (27) 
Tohit bonus  +2 +1d3 
Bonus versus  fail monster MR check or player without MR 
Weapon skill  dagger 
Size  onehanded 
Affiliation  
When carried 
(none) 
When wielded 

When invoked 
(none) 
Base price  3500 zm 
Weight  10 
Material  iron 
Magicbane is an artifact athame. It is considered a dagger for skill purposes, and has a 40% chance of having a magical effect on the victim as well as inflicting damage.^{[1]} Throwing Magicbane can have the same effect on a monster it hits. Care should be taken not to throw at an enemy that can pick it up and wield it, conferring magic resistance to the monster.
Like all athames, when blessed or uncursed Magicbane can also engrave a semipermanent Elbereth without dulling and in one turn.
Contents
Magical effects
The "bonus" effects that Magicbane can produce are:
Each of these effects produces the following message:
 "The magicabsorbing blade probes/stuns/scares/cancels the <monster>!"
When hallucinating, the messages corresponding to these bonus effects are changed to "prod", "amaze", "tickle" and "purge" respectively.^{[2]}
Any bonus effect adds an additional 1d4 damage. Though the chance of some type of magical bonus effect is always 40%, Magicbane's level of enchantment affects the probability of each type of effect differently.
When a spellcasting monster is cancelled, some magical energy is also absorbed, and your current and maximum energy are increased by 1 (“You absorb magical energy!”)^{[3]}. Cancellation is the only one of Magicbane's effects that can absorb magical energy. This effect happens every time the cancellation attack hits, not just the first time when the monster is actually cancelled, so this could be farmed.
In addition, Magicbane catches and resists 95% of curses sent to the wielder and gives magic resistance.
Enchanting
Magicbane has two reactions if it's enchanted to +0 or above:
 "Your right hand itches!" (+0 or +1)
 "Your right hand flinches" (+2 or higher)
Magicbane enchanted to +2 has the best chance of inflicting valuable magical effects. The chance of stunning drops progressively from +0, scaring and cancellation drop progressively after +2, and cancellation is eliminated after +5; probing takes their place. However, the average damage it inflicts increases with each level of enchantment, which is typically desirable for dealing maximum damage as a primary weapon. ^{[4]}.
Increasing Magicbane's enchantment from +6 to +7 is typically not worth the effort. As with other weapons, you need to lower it to +5 to safely attempt to enchant to +7. But lowering Magicbane's enchantment can be very difficult. Because it's an athame, engraving with it will not dull it. Because it's an artifact, it will resist most attempts at disenchantment from a cursed scroll of enchant weapon. The drain life spell can work, but typically takes many attempts. Hitting a disenchanter with Magicbane can also work, though note that the disenchanter may be able to disenchant your armor if you stand around hitting it for too long (the attack is subject to magic cancellation, so this is rarely a major issue by the time you're worried about enchanting Magicbane to +7).
If you have copious amounts amounts of holy water and unholy water on hand, it is also possible to lower Magicbane's enchantment by cursing it with unholy water and engraving a single letter with it. Remember to rebless it afterward.
Generation
Wizards receive Magicbane as their first gift from their god after sacrificing at an altar.
As with all artifacts associated to a specific role. Magicbane will always match the initial alignment of the wizard, regardless of it's generation method (wish, bones levels).
Archliches have a minuscule (1/1170, or approximately 0.085%) chance of being generated with Magicbane. Even hunting them until extinction yields only a 9.75% chance of Magicbane appearing, and if you can safely hunt archliches, you probably don't need Magicbane anyway.
Damage
Strength, skill and blessed damage bonuses are also added.
Note the progressive drop of stun from +0, the progressive drop of scare and cancel after +2, and cancel is eliminated after +5 while average damage keeps increasing.
Enchantment  Monster Resisted  Base Damage  Chance of +1d4 Extra  Chance of +1d4 Stun  Chance of +1d4 Scare  Chance of +1d4 Cancel  Mean Damage 

+0  No  (1d4 or 1d3) + 1d4  8 / 20  8 / 20 * 10 / 11  4 / 20  2 / 20  7.66 or 7.16 
Yes  1d4 or 1d3  8 / 20  8 / 20 * 6 / 7  3 / 20  1 / 20  4.86 or 4.36  
+1  No  (1d4 or 1d3) + 1d4 + 1  8 / 20  8 / 20 * 9 / 11  4 / 20  2 / 20  8.57 or 8.07 
Yes  (1d4 or 1d3) + 1  8 / 20  8 / 20 * 5 / 7  3 / 20  1 / 20  5.71 or 5.21  
+2  No  (1d4 or 1d3) + 1d4 + 2  8 / 20  8 / 20 * 8 / 11  4 / 20  2 / 20  9.48 or 8.98 
Yes  (1d4 or 1d3) + 2  8 / 20  8 / 20 * 4 / 7  3 / 20  1 / 20  6.57 or 6.07  
+3  No  (1d4 or 1d3) + 1d4 + 3  8 / 20  8 / 20 * 7 / 11  2 / 20  1 / 20  10.01 or 9.51 
Yes  (1d4 or 1d3) + 3  8 / 20  8 / 20 * 3 / 7  1 / 20  0 / 20  7.05 or 6.55  
+4  No  (1d4 or 1d3) + 1d4 + 4  8 / 20  8 / 20 * 6 / 11  2 / 20  1 / 20  10.92 or 10.42 
Yes  (1d4 or 1d3) + 4  8 / 20  8 / 20 * 2 / 7  1 / 20  0 / 20  7.91 or 7.41  
+5  No  (1d4 or 1d3) + 1d4 + 5  8 / 20  8 / 20 * 5 / 11  2 / 20  1 / 20  11.83 or 11.33 
Yes  (1d4 or 1d3) + 5  8 / 20  8 / 20 * 1 / 7  1 / 20  0 / 20  8.77 or 8.27  
+6  No  (1d4 or 1d3) + 1d4 + 6  8 / 20  8 / 20 * 4 / 11  1 / 20  0 / 20  12.49 or 11.99 
Yes  (1d4 or 1d3) + 6  8 / 20  8 / 20 * 0 / 7  0 / 20  0 / 20  9.5 or 9  
+7  No  (1d4 or 1d3) + 1d4 + 7  8 / 20  8 / 20 * 3 / 11  1 / 20  0 / 20  13.40 or 12.90 
Yes  (1d4 or 1d3) + 7  8 / 20  8 / 20 * 0 / 7  0 / 20  0 / 20  10.5 or 10  
+8  No  (1d4 or 1d3) + 1d4 + 8  8 / 20  8 / 20 * 2 / 11  1 / 20  0 / 20  14.31 or 13.81 
Yes  (1d4 or 1d3) + 8  8 / 20  8 / 20 * 0 / 7  0 / 20  0 / 20  11.5 or 11  
+9  No  (1d4 or 1d3) + 1d4 + 9  8 / 20  8 / 20 * 1 / 11  0 / 20  0 / 20  15.09 or 14.59 
Yes  (1d4 or 1d3) + 9  8 / 20  8 / 20 * 0 / 7  0 / 20  0 / 20  12.5 or 12  
+10 or more  No  (1d4 or 1d3) + 1d4 + Enchantment  8 / 20  8 / 20 * 0 / 11  0 / 20  0 / 20  (6 or 5.5) + Enchantment 
Yes  (1d4 or 1d3) + Enchantment  8 / 20  8 / 20 * 0 / 7  0 / 20  0 / 20  (3.5 or 3) + Enchantment 
Exact mechanics
The base damage is 1d4 to small monsters and 1d3 to large monsters. If the monster fails a magic resistance check, an additional 1d4 damage is added to the base damage and the further special attacks are more likely. This magic resistance check is, however, an unusual one, because it doesn't consider level bonuses. There is an 8 / 20 (40%) chance of an additional +1d4 damage and possibly more. Given there is additional damage:
 There is a chance of an additional +1d4 stun damage.
 If the monster failed the previous magic resistance check, the probability of this stun damage is .
 If the monster passed the magic resistance check, the probability of this stun damage is .
 There is a chance of an additional +1d4 scare damage or +2d4 scare & cancellation damage.
 The roll for scare or cancellation damage is scaled by , where is integer division. The base roll for scare damage is and the base roll for cancellation damage is . ^{[5]}
 If the monster failed the previous magic resistance check, the probability of scare damage is simply and the probability of cancellation damage is simply .
 If the monster passed the previous magic resistance check, the probability of scare damage is and the probability of cancellation damage is .
 Exactly one of the following occurs:
 The probability of +1d4 scare damage is .
 The probability of +2d4 scare & cancellation damage is . (Note that this means there is a probability of +1d4 scare and a probability of +1d4 cancellation, which is used in the table below.)
 The probability of no scare or cancellation damage is .
 If there is also no stun damage, the attack probes. The probe has a 1 in (abs(enchantment) * 3) of being insightful and actually probing the monster, otherwise nothing happens. The +0 magicbane will always successfully probe the target.
 The roll for scare or cancellation damage is scaled by , where is integer division. The base roll for scare damage is and the base roll for cancellation damage is . ^{[5]}
 Finally, there is a 1in12 chance of confusing the target with any magical attack. This chance is not affected by enchantment.
The monster can resist the scare and cancellation effects using a Magic resistance (monster) check (if you are attacked, you resist if you have Magic resistance instead), but the extra damage of these effects is dealt even in that case. The monster cannot resist the stun, probe, or confuse effects.^{[1]}
SLASH'EM
) Magicbane  

Base item  athame 
Damage vs. small  1d4 + 4 + (special) (28) 
Damage vs. large  1d3 + 4 + (special) (27) 
Tohit bonus  +2 +3 
Bonus versus  fail monster MR check or player without MR 
Weapon skill  dagger 
Size  onehanded 
Affiliation  
When carried 
(none) 
When wielded 

When invoked 
(none) 
Base price  3500 zm 
Weight  10 
Material  iron 
The damage is the same in SLASH'EM, except failing a magic resistance check adds +4, not +1d4. (In the table above, this is replacing '+ 1d4' with '+ 4' in the base damage column when 'Monster Resisted' is 'No', which adds 1.5 to the mean damage in these cases.)^{[6]}
SLASH'EM gives the option of wielding artifacts as one's secondary weapon, but note that Magicbane will not convey its curse or magic resistance unless it is wielded as a primary weapon.
Additionally, even a +0 Magicbane hits all monsters, even if they normally require an enchanted weapon to hit. Technically, it is the only such weapon in SLASH'EM, although Lightsabers (considered tools by the game) can also hit all monsters at +0.
See also
References
 ↑ ^{1.0} ^{1.1} Mb_hit in artifact.c
 ↑ artifact.c in NetHack 3.6.0, line 942
 ↑ artifact.c in NetHack 3.6.0, line 1040
 ↑ http://www.steelypips.org/nethack/343/art2343.html
 ↑ (The rolls are out of 20, but require at least an 8 out of 20, which is why 8 is used as the denominator below).
 ↑ Source:SLASH'EM 0.0.7E7F2/artifact.c.