Difference between revisions of "Magic contamination"

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'''Magic contamination''' is a potential side effect of powerful magic, divine wrath or favour, or the incompetent use of magic.
 
'''Magic contamination''' is a potential side effect of powerful magic, divine wrath or favour, or the incompetent use of magic.
  
== Overview ==
+
==Overview==
 
 
 
Various activities cause harmful magical energies to accumulate in your body. A small amount of magical contamination is basically harmless, and will dissipate over time without any further effect. Larger amounts of accumulated magic contamination (five or more points) will make you start to Glow with magical energy; glowing is bad for two reasons.
 
Various activities cause harmful magical energies to accumulate in your body. A small amount of magical contamination is basically harmless, and will dissipate over time without any further effect. Larger amounts of accumulated magic contamination (five or more points) will make you start to Glow with magical energy; glowing is bad for two reasons.
 +
*A glowing target is easier to hit.
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*You may suffer damage and mutations from the magical energies your body has absorbed.
  
* A glowing target is easier to hit.
+
==Accumulation==
* You may suffer damage and mutations from the magical energies your body has absorbed.
 
 
 
== Accumulation ==
 
 
Your magic contamination level can be increased by:
 
Your magic contamination level can be increased by:
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===Haste===
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*Spending time under the influence of [[Haste]] while not [[Berserk]].
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*+1 point for becoming hasted using a Haste spell or [[wand of hasting]].
 +
*+1 point for having your already-in-force Haste effect extended by:
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**Rage extension (Z)
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**A potion of haste or berserk rage (Z)
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**Xom sending you berserk.
 +
**Invoking Okawaru's Haste power
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*+2 points for having your Haste extended by:
 +
**The Haste spell or a wand of hasting. (Z)
  
=== Haste ===
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===Invisibility===
* Spending time under the influence of [[Haste]] while not [[Berserk]].
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*Spending time [[invisible]].
* +1 point for becoming hasted using a Haste spell or [[wand of hasting]].
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*+1 point for making yourself invisible with a [[wand of invisibility]] or the [[Invisibility]] spell.(Z)
* +1 point for having your already-in-force Haste effect extended by:
 
** rage extension (Z)
 
** a potion of haste or berserk rage (Z)
 
** Xom sending you berserk.
 
** invoking Okawaru's Haste power
 
* +2 points for having your Haste extended by:
 
** the Haste spell or a wand of hasting. (Z)
 
 
 
=== Invisibility ===
 
* Spending time [[invisible]].
 
* +1 point for making yourself invisible with a [[wand of invisibility]] or the [[Invisibility]] spell.(Z)
 
  
=== Might ===
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===Might===
* +1 point for extending Might by:
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*+1 point for extending Might by:
** quaffing a potion of Might (Z)
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**Quaffing a potion of might (Z)
** invoking Okawaru's Might power
 
  
=== Teleport Control ===
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===Teleport Control===
* +1 point every time you ''successfully'' control a teleportation. (Z)
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*+1 point every time you ''successfully'' control a teleportation. (Z)
* +1 point every time you make a ''fully-controlled'' blink. (Z)
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*+1 point every time you make a ''fully-controlled'' blink. (Z)
  
=== Miscasts and Miscast Effects ===
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===Miscasts and Miscast Effects===
* [[Miscasting]] spells.
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*[[Miscasting]] spells.
* Being struck by the Divinations miscast effect of Sif Muna's wrath.
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*Being struck by the Divinations miscast effect of Sif Muna's wrath.
* Wielding or unwielding a weapon with the [[distortion]] brand. (Z)
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*Wielding or unwielding a weapon with the [[distortion]] brand. (Z)
* The capriciousness of [[Xom]] inflicting a miscast effect on you.
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*The capriciousness of [[Xom]] inflicting a miscast effect on you.
* Zot traps (which apply random miscasts).
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*Zot traps (which apply random miscasts).
  
=== Other ===
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===Other===
* Quaffing a [[potion of resistance]]. (Z)
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*Quaffing a [[potion of resistance]]. (Z)
* Equipping an [[artifact]] which emits (or, even worse, glows with) mutagenic radiation.
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*Equipping an [[artifact]] which emits (or, even worse, glows with) mutagenic radiation.
  
 
Any behaviour marked with (Z) will reduce the piety of worshippers of Zin.
 
Any behaviour marked with (Z) will reduce the piety of worshippers of Zin.
  
=== Spending Time ===
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===Spending Time===
 
For purposes of the above, "spending time" under the influence of an effect means having that effect in force when the handle_time() function is called (roughly once every 20 turns). When this occurs:
 
For purposes of the above, "spending time" under the influence of an effect means having that effect in force when the handle_time() function is called (roughly once every 20 turns). When this occurs:
* 60% chance of +1 contamination if you are invisible.
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*60% chance of +1 contamination if you are invisible.
* 60% chance of +1 contamination if you are hasted and not berserk.
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*60% chance of +1 contamination if you are hasted and not berserk.
  
=== Base contamination for miscasts ===
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===Base Contamination for Miscasts===
 
To figure the baseline contamination level for a miscast, use the following calculation.
 
To figure the baseline contamination level for a miscast, use the following calculation.
  
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       With C being your final number. Fractional points are rounded randomly.
 
       With C being your final number. Fractional points are rounded randomly.
  
=== Contaminating miscast effects ===
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===Contaminating Miscast Effects===
 
The following miscasts can give you up to 18 contamination:
 
The following miscasts can give you up to 18 contamination:
* Severity-3 Enchantments (25% chance)
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*Severity-3 Enchantments (25% chance)
* Severity-3 Translocations (25% chance)
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*Severity-3 Translocations (25% chance)
* Severity-2 Transmutations (25% chance)
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*Severity-2 Transmutations (25% chance)
  
 
The following miscasts can give you up to 34 contamination:
 
The following miscasts can give you up to 34 contamination:
* Severity-3 Transmutations (25% chance)
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*Severity-3 Transmutations (25% chance)
  
== Dissipation ==
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==Dissipation==
 
Dissipation of magic contamination is handled by the handle_time() function. Each time it is called:
 
Dissipation of magic contamination is handled by the handle_time() function. Each time it is called:
 
+
*If you are neither Hasted (whether berserk or not) nor Invisible, you have a 50% chance of harmlessly dissipating one point of magic contamination.
* If you are neither Hasted (whether berserk or not) nor Invisible, you have a 50% chance of harmlessly dissipating one point of magic contamination.
+
*If you have 5 or more points of magic contamination, there is a 50% chance of a violent discharge occurring. The effects of this are as follows:
* If you have 5 or more points of magic contamination, there is a 50% chance of a violent discharge occurring. The effects of this are as follows:
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**If you are in a [[Zin|Sanctuary]], there is a ((total contamination + 1) * 4)% chance of being told that Zin has prevented a violent discharge of magical energies.
** If you are in a [[Zin|Sanctuary]], there is a ((total contamination + 1) * 4)% chance of being told that Zin has prevented a violent discharge of magical energies.
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**If the previous check failed (either the random roll was too high, or you weren't in a sanctuary to begin with), then there is a ((total contamination + 1) * 4)% chance of some of your contamination discharging violently. When this occurs:
** If the previous check failed (either the random roll was too high, or you weren't in a sanctuary to begin with), then there is a ((total contamination + 1) * 4)% chance of some of your contamination discharging violently. When this occurs:
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***If your contamination total is 10 or higher then there is a 50% chance of a magical [[#Explosions from glow|explosion]] erupting from your body.
*** If your contamination total is 10 or higher then there is a 50% chance of a magical [[#Explosions from glow|explosion]] erupting from your body.
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***You receive one mutation. 20% of the time this will be an entirely random mutation; the rest of the time it will be from the list of bad mutations. Mutation resistance applies as normal.
*** You receive one mutation. 20% of the time this will be an entirely random mutation; the rest of the time it will be from the list of bad mutations. Mutation resistance applies as normal.
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***A random amount of magic contamination (always at least one point, never more than 25% of your current contamination amount) is removed.
*** A random amount of magic contamination (always at least one point, never more than 25% of your current contamination amount) is removed.
 
  
 
The magical explosions unleashed by violent discharge of magic contamination do damage specified by:
 
The magical explosions unleashed by violent discharge of magic contamination do damage specified by:
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For example, if you are not undead, and have 50 points of magical contamination (this is a really, really severe problem...), you will take 3d25 (3-75) of unresistable damage (AC applies).
 
For example, if you are not undead, and have 50 points of magical contamination (this is a really, really severe problem...), you will take 3d25 (3-75) of unresistable damage (AC applies).
  
== Anti-magic and contamination ==
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==Antimagic and Contamination ==
 
Reading a [[scroll of vulnerability]] will harmlessly reduce your magic contamination by 1d5 points.  This is a good reason to carry and save these rare scrolls, as their other effect, halving the MR of nearby monsters, is generally not that useful to most characters.
 
Reading a [[scroll of vulnerability]] will harmlessly reduce your magic contamination by 1d5 points.  This is a good reason to carry and save these rare scrolls, as their other effect, halving the MR of nearby monsters, is generally not that useful to most characters.
  
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==History==
 
==History==
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Prior to 0.10, this effect was simply called [[glow]], a term which ambiguously referred either to magic contamination, or to the relatively harmless glow from [[Sticky Flame]] or [[Corona]].
  
Prior to 0.10, this effect was simply called [[glow]], a term which ambiguously referred either to magic contamination, or to the relatively harmless glow from [[sticky flame]] or [[corona]].
+
[[Category:Magic]][[Category:Game mechanics]][[Category:Status effects]]
 
 
[[Category:Magic]] [[Category:Game mechanics]]
 

Revision as of 20:50, 25 April 2013

Version 0.11: This article may not be up to date for the latest stable release of Crawl.


Magic contamination is a potential side effect of powerful magic, divine wrath or favour, or the incompetent use of magic.

Overview

Various activities cause harmful magical energies to accumulate in your body. A small amount of magical contamination is basically harmless, and will dissipate over time without any further effect. Larger amounts of accumulated magic contamination (five or more points) will make you start to Glow with magical energy; glowing is bad for two reasons.

  • A glowing target is easier to hit.
  • You may suffer damage and mutations from the magical energies your body has absorbed.

Accumulation

Your magic contamination level can be increased by:

Haste

  • Spending time under the influence of Haste while not Berserk.
  • +1 point for becoming hasted using a Haste spell or wand of hasting.
  • +1 point for having your already-in-force Haste effect extended by:
    • Rage extension (Z)
    • A potion of haste or berserk rage (Z)
    • Xom sending you berserk.
    • Invoking Okawaru's Haste power
  • +2 points for having your Haste extended by:
    • The Haste spell or a wand of hasting. (Z)

Invisibility

Might

  • +1 point for extending Might by:
    • Quaffing a potion of might (Z)

Teleport Control

  • +1 point every time you successfully control a teleportation. (Z)
  • +1 point every time you make a fully-controlled blink. (Z)

Miscasts and Miscast Effects

  • Miscasting spells.
  • Being struck by the Divinations miscast effect of Sif Muna's wrath.
  • Wielding or unwielding a weapon with the distortion brand. (Z)
  • The capriciousness of Xom inflicting a miscast effect on you.
  • Zot traps (which apply random miscasts).

Other

Any behaviour marked with (Z) will reduce the piety of worshippers of Zin.

Spending Time

For purposes of the above, "spending time" under the influence of an effect means having that effect in force when the handle_time() function is called (roughly once every 20 turns). When this occurs:

  • 60% chance of +1 contamination if you are invisible.
  • 60% chance of +1 contamination if you are hasted and not berserk.

Base Contamination for Miscasts

To figure the baseline contamination level for a miscast, use the following calculation.

     A= (spell_level ^ 2) * margin_of_failure
     B= A+250
     C= B/500
     With C being your final number. Fractional points are rounded randomly.

Contaminating Miscast Effects

The following miscasts can give you up to 18 contamination:

  • Severity-3 Enchantments (25% chance)
  • Severity-3 Translocations (25% chance)
  • Severity-2 Transmutations (25% chance)

The following miscasts can give you up to 34 contamination:

  • Severity-3 Transmutations (25% chance)

Dissipation

Dissipation of magic contamination is handled by the handle_time() function. Each time it is called:

  • If you are neither Hasted (whether berserk or not) nor Invisible, you have a 50% chance of harmlessly dissipating one point of magic contamination.
  • If you have 5 or more points of magic contamination, there is a 50% chance of a violent discharge occurring. The effects of this are as follows:
    • If you are in a Sanctuary, there is a ((total contamination + 1) * 4)% chance of being told that Zin has prevented a violent discharge of magical energies.
    • If the previous check failed (either the random roll was too high, or you weren't in a sanctuary to begin with), then there is a ((total contamination + 1) * 4)% chance of some of your contamination discharging violently. When this occurs:
      • If your contamination total is 10 or higher then there is a 50% chance of a magical explosion erupting from your body.
      • You receive one mutation. 20% of the time this will be an entirely random mutation; the rest of the time it will be from the list of bad mutations. Mutation resistance applies as normal.
      • A random amount of magic contamination (always at least one point, never more than 25% of your current contamination amount) is removed.

The magical explosions unleashed by violent discharge of magic contamination do damage specified by:

dice_def(3, you.magic_contamination * (you.is_undead ? 4 : 2) / 4)

For example, if you are not undead, and have 50 points of magical contamination (this is a really, really severe problem...), you will take 3d25 (3-75) of unresistable damage (AC applies).

Antimagic and Contamination

Reading a scroll of vulnerability will harmlessly reduce your magic contamination by 1d5 points. This is a good reason to carry and save these rare scrolls, as their other effect, halving the MR of nearby monsters, is generally not that useful to most characters.

One of the aspects of Sif Muna's wrath is reducing the remaining duration of all your enchantments to 1 turn; when this occurs, your magic contamination level is also reduced by 1d5 points.

History

Prior to 0.10, this effect was simply called glow, a term which ambiguously referred either to magic contamination, or to the relatively harmless glow from Sticky Flame or Corona.