Bad mutations

Version 0.34: This article is up to date for the latest stable release of Dungeon Crawl Stone Soup.

Here is a list of all the bad mutations you can acquire. Although some may have situational uses, they are at best mixed blessings. Regardless, "bad mutation" is a technical term used by the game, not a qualitative judgement. Any of these can be acquired through any source of bad mutations.

Offensive

Reckless

Rank	Effect	Flavor
1	Your SH is halved, but the damage you deal with two-handed weapons is increased by 15%	Your SH is halved, but you deal more damage with two-handed weapons
Bad mutation, or good mutation? If life gives you lemons, smack life upside the head with a triple sword.
Bad mutation

Defensive

Deformed Body

Rank	Effect	Flavor
1	Reduces body armour base AC by 40%.	Armour fits poorly on your strangely shaped body.
Does not stack with Jiyva's Pseudopods mutation. AC bonus from Armour skill is affected. Does not affect AC from any other source (i.e. other equipment, armour enchantment, the protection ego, etc.).
Species notes: Nagas and Armataurs start with this mutation. Draconians, octopodes and felids cannot gain this mutation as they cannot wear body armour.
Bad mutation

Screaming

Rank	Effect	Flavor
1	Chance to shout loudly whenever the player is damaged (same noise as tt).	You occasionally shout uncontrollably at your foes.
2	Greater chance for louder shouts.	You sometimes yell uncontrollably at your foes.
3	Greatest chance for loudest shouts.	You frequently scream uncontrollably at your foes.
Bad mutation

Teleportitis

Rank	Effect	Flavor
1	You are sometimes teleported next to a monster.	You are occasionally teleported next to monsters.
2	More frequent teleportation.	You are often teleported next to monsters.
Species Notes: Formicids can not teleport and thus can not get this mutation. Teleportitis gives the player a few turns of a !Tele! status before they will be teleported towards monsters, can be cancelled by reading a Scroll of teleportation.
Bad mutation

Electricity Vulnerability

Rank	Effect	Flavor
1	rElec-	You are vulnerable to electricity.
Qazlal may give you this mutation as a punishment.
Bad mutation

Heat Vulnerability

Rank	Effect	Flavor
1	rF-	You are vulnerable to heat.
2	rF--	You are very vulnerable to heat.
3	rF---	You are extremely vulnerable to heat.
Qazlal may give you this mutation as a punishment.
Bad mutation

Cold Vulnerability

Rank	Effect	Flavor
1	rC-	You are vulnerable to cold.
2	rC--	You are very vulnerable to cold.
3	rC---	You are extremely vulnerable to cold.
Qazlal may give you this mutation as a punishment.
Bad mutation

Consumable usage

Booming Voice

Rank	Effect	Flavor
1	Produce Gong-level noise (40) when reading scrolls in view of enemies.	When reading scrolls in sight of hostile monsters, your voice resounds with a truly stupendous volume.
Bad mutation

No Potion Heal

Rank	Effect	Flavor
1	Potions heal 50% of what they would normally.	Potions are less effective at restoring your health.
2	Potions do not restore any HP.	Potions cannot restore your health.
Includes potion of curing, potion of heal wounds, and potion of ambrosia. Note that other effects (curing status, ambrosia MP regen) are unaffected. Also, Gozag's effects are unaffected.
Species information: Vine Stalkers start at rank 2.
Bad mutation

General

Spiteful Blood

Rank	Effect	Flavor
1	When falling below 50% max HP, an erythrospite may spawn adjacent to you	Your shed blood may rise up to attack you
2	When falling below 50% max HP, 2 erythrospites may spawn adjacent to you	Your shed blood may rise up to attack you as a group
At the first rank, if one spawns, a second will not be able to spawn until the player heals fully (and then gets significantly reinjured). This scales to rank 2.
Bad mutation

Spatial Entanglement

Rank	Effect
1	66% chance, whenever you move via a translocation, of pulling a single random monster along for the ride
If you move to somewhere in LoS of your old position, it pulls a random monster previously in LoS of you (preferring monsters not still in LoS of your new location). If you move teleport further away, it can pull a random monster from anywhere else on the floor. The monster pulled is stunned for one turn, ensuring the player can always act again before they can.
Bad mutation

Potion Fungus

Rank	Effect
1	Sometimes shares the effect of beneficial potions they drink with other monsters
This *can* affect allies, but since there are a lot more enemies in the game than allies (and many characters have no allies at all), this is intended to be primarily a negative mutation.
Bad mutation

Initially attractive

Rank	Effect
1	You sometimes pull newly seen creatures towards you
2	You frequently pull newly seen creatures towards you
50% chance of waking up any monsters pulled by it (though not alerting themselves to the player's position, so stealthy characters may still remain briefly unnoticed).
Bad mutation

Meek

Rank	Effect
1	-3 Slaying
2	-5 Slaying
3	-7 Slaying
All of your attacks are less effective, dealing less damage and being a little less accurate.
Bad mutation

Poor Constitution

Rank	Effect	Flavor
1	A 1/9 chance to inflict weakness whenever you take damage that is greater than 1/15th of your max HP	Your body sometimes grows weak upon taking damage.
2	A 1/6 chance to inflict weakness whenever you take damage that is greater than 1/15th of your max HP If weakness is inflicted, there is an additional 1/2 chance to inflict slowness.	Your body sometimes grows weak and slow upon taking damage.
Bad mutation

Devolution

Rank	Effect	Flavor
1	Gain further malmutations until trait expires.	You have hidden genetic defects.
2	Same as previous level, though lasts longer.	You have terrible hidden genetic defects.
Triggers about every 1/4 XL's worth of XP, providing another bad mutation. Every two activations it reduces its level by one.
Bad mutation

Frail

Rank	Effect	Flavor
1	Max HP -10%	You are frail.
2	Max HP -20%	You are very frail.
3	Max HP -30%	You are extremely frail.
Bad mutation

Low MP

Rank	Effect	Flavor
1	Max MP -10%	Your magical capacity is low.
2	Max MP -20%	Your magical capacity is very low.
3	Max MP -30%	Your magical capacity is extremely low.
Bad mutation

Reduced Attributes

Rank	Effect	Flavor
1	-3 to STR, INT or DEX	You are weak You are dopey. You are clumsy.
2	-6 to STR, INT or DEX	You are very weak You are very dopey. You are very clumsy.
While it's possible to gain this mutation multiple times, each attribute is limited to 2 ranks.
Bad mutation

Inhibited Regeneration

Rank	Effect	Flavor
1	No regular HP regeneration when monsters are in line of sight.	You do not regenerate when monsters are visible.
Jiyva's regen and Trog's Hand function normally, though all other external regeneration sources fail. For this mutation's history, see Inhibited Regeneration#History.
Species Notes: Ghouls start at rank 1. Vampires have this mutation when Bloodless, and thus unable to get it randomly.
Bad mutation

Subdued Magic

Rank	Effect	Flavor
1	Spell Power-, Spell Success+	Your spells are a little easier to cast, but a little less powerful.
2	Spell Power--, Spell Success++	Your spells are easier to cast, but less powerful.
3	Spell Power---, Spell Success+++	Your spells are much easier to cast, but much less powerful.
Each level gives -20% (additively stacked, then multiplied) to raw spellpower and -2% (additive) to raw spell failure rate. Generally, the impact will be less than -20% power and -2% failure, respectively.
Bad mutation

Persistent Drain

Rank	Effect	Flavor
1	Your health recovers twice as slowly from being drained.	You begin to recover more slowly from draining effects.
Bad mutation

See Also

• Good mutations
• Demonspawn mutations
• Jiyva mutations

History

• In 0.34, several new good mutations were added, with some adjusted, alongside the major mutation rework.
• In 0.33, Deterioration was replaced with Poor Constitution. Deformed armour base AC reduction decreased from 50% to 40%.
• In 0.31, Persistent Drain was introduced.
• In 0.30, Heat and Cold Vulnerability became regular mutations.
• In 0.29, No Unsafe Potions became a regular mutation. Many mutations were increased/reduced to 2 levels.
• In 0.28, Devolution was introduced.
• In 0.27, Blurry Vision was replaced with No Unsafe Scrolls.
• Prior to 0.22, MP-Powered Wands was different and considered a bad mutation.
• Prior to 0.20, the Inhibited Regeneration mutation had 3 ranks.
• Prior to 0.17, the Forlorn mutation was available.
• Prior to 0.15, the Slow/Fast metabolism mutations were available as random mutations.
• Prior to 0.14 the Slow Movement mutation occurred randomly and levels 1 and 2 of the Slow Healing mutation cut natural regeneration by 33% and 66% respectively, regardless of enemy presence.
• Prior to 0.13, Reduced Attributes could be acquired up to 14 times, giving you -1 per rank.

ouch.cc:997 (0.34.1)