Disruption

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Revision as of 23:22, 20 August 2022 by Hordes (talk | contribs) (an average of +150% per hit and 2/3 chance to proc is 100%)
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Version 0.28: This article may not be up to date for the latest stable release of Crawl.

Disruption is a special brand found only on the artefact great mace, Undeadhunter. Each time it strikes an undead target and deals damage dam, there is a 2/3 probability for the target to be blasted with disruptive energy up to an additional +300% damage. On average, you deal an extra +100% damage to undead targets.

Damage Calculation

Unlike most brands, bonus damage is not linearly distrubuted. Additional damage is calculated according to the formula:

random2avg((1 + (dam * 3)), 3))[1]

random2avg[2] takes the average of 3 rolls, here, which means the resulting extra damage approximates a normal distribution with a mean of 3/2 × dam[3] and a standard deviation of approximately 1/2 × dam[4].

Following the normal distrubution[5], additional damage dealt is between +100% and +200% damage, 68% of the time, and between +50% and +250% damage 95% of the time. (Assuming it deals extra damage at all)

History

  • In 0.9, Disruption was made an exclusive brand to the Undeadhunter.
  • Prior to 0.4, Disruption was a normal brand found on random melee weapons. Holy wrath was enhanced in its stead.

References

  1. art-func.h:637 (0.28.0)
  2. random.cc:327 (0.28.0)
  3. random2avg returns an int, which shifts the mean slightly downwards from this value due to the effect of integer truncation for division in C++.
  4. More exactly: 1/2 × sqrt[(dam × dam) + (dam / 3)]. The difference between the two calculations is negligible, as the increase is between 0.08 and 0.083(3) for any dam above 1.
  5. https://en.wikipedia.org/wiki/68%E2%80%9395%E2%80%9399.7_rule
Brands
Melee weapons AntimagicChaosDistortionDrainingElectrocutionFlamingFreezingHeavyHoly wrathPainProtectionReachingSpectralSpeedVampiricVenom
DisruptionDragon slayingReapingSilver
Launchers AntimagicDrainingElectrocutionFlamingFreezingHeavyPenetrationSpeed
Throwing weapons AtropaCurareDaturaDispersalPoisonedSilver