diff --git a/bonemarketsolver/data/adjustments.py b/bonemarketsolver/data/adjustments.py
index 7fcba4e..bfc7500 100644
--- a/bonemarketsolver/data/adjustments.py
+++ b/bonemarketsolver/data/adjustments.py
@@ -5,29 +5,8 @@ from enum import Enum
 
 from .costs import Cost
 from ..objects.action import Action
-from ..read_char import *
-
-
-def _narrow_challenge_6(stat: int):
-    if 0 < stat < 11:
-        chance = stat/10
-    elif stat < 1:
-        chance = .1
-    else:
-        chance = 1
-
-    return chance
-
-
-def _implausibility(stat: int):
-    chance = _narrow_challenge_6(stat)
-
-    if chance == 1:
-        return 0
-    else:
-        failure_actions = (1 / chance) - 1
-        implausibility = 2 * failure_actions
-        return implausibility
+from ..read_char import Char
+from ..challenge_functions import narrow_challenge, mean_outcome
 
 
 class Adjustment(Enum):
@@ -35,23 +14,23 @@ class Adjustment(Enum):
 
     CARVE_AWAY_AGE = Action(
             "Carve away some evidence of age",
-            cost = Cost.ACTION.value / _narrow_challenge_6(Char.MITHRIDACY.value),
+            cost = Cost.ACTION.value / narrow_challenge(6, Char.MITHRIDACY.value),
             antiquity = -2,
-            implausibility = _implausibility(Char.MITHRIDACY.value)
+            implausibility = mean_outcome(0, 2, narrow_challenge(6, Char.MITHRIDACY.value))
             )
 
     DISGUISE_AMALGAMY = Action(
             "Disguise the amalgamy of this piece",
-            cost = 25*Cost.JADE_FRAGMENT.value + Cost.ACTION.value / _narrow_challenge_6(Char.KATALEPTIC_TOXICOLOGY.value),
+            cost = 25*Cost.JADE_FRAGMENT.value + Cost.ACTION.value / narrow_challenge(6, Char.KATALEPTIC_TOXICOLOGY.value),
             amalgamy = -2,
-            implausibility = _implausibility(Char.KATALEPTIC_TOXICOLOGY.value)
+            implausibility = mean_outcome(0, 2, narrow_challenge(6, Char.KATALEPTIC_TOXICOLOGY.value))
             )
 
     MAKE_LESS_DREADFUL = Action(
             "Make your skeleton less dreadful",
-            cost = Cost.ACTION.value / _narrow_challenge_6(Char.KATALEPTIC_TOXICOLOGY.value),
+            cost = Cost.ACTION.value / narrow_challenge(6, Char.KATALEPTIC_TOXICOLOGY.value),
             menace = -2,
-            implausibility = _implausibility(Char.KATALEPTIC_TOXICOLOGY.value)
+            implausibility = mean_outcome(0, 2, narrow_challenge(6, Char.KATALEPTIC_TOXICOLOGY.value))
             )
 
     def __str__(self):
diff --git a/bonemarketsolver/data/appendages.py b/bonemarketsolver/data/appendages.py
index 91fae0b..4c29475 100644
--- a/bonemarketsolver/data/appendages.py
+++ b/bonemarketsolver/data/appendages.py
@@ -5,8 +5,8 @@ from enum import Enum
 
 from .costs import Cost
 from ..objects.action import Action
-from ..read_char import *
-from ..challenge_functions import narrow_challenge, mean_outcome
+from ..read_char import Char
+from ..challenge_functions import narrow_challenge, broad_challenge, mean_outcome
 
 
 class Appendage(Enum):
@@ -128,7 +128,8 @@ class Appendage(Enum):
             cost = Cost.ACTION.value + Cost.IVORY_FEMUR.value,
             value = 6500,
             limbs_needed = -1,
-            legs = 1
+            legs = 1,
+            implausibility = mean_outcome(0, 4, narrow_challenge(7, Char.MONSTROUS_ANATOMY.value))
             )
 
     IVORY_HUMERUS = Action(
@@ -136,9 +137,12 @@ class Appendage(Enum):
             cost = Cost.ACTION.value + Cost.IVORY_HUMERUS.value,
             value = 1500,
             limbs_needed = -1,
-            arms = 1
+            arms = 1,
+            implausibility = mean_outcome(0, 2, narrow_challenge(6, Char.KATALEPTIC_TOXICOLOGY.value))
             )
 
+    # TODO: Base challenge: Narrow, Mithridacy 1
+    #       Difficulty increases by 2 for each Fin or Tentacle already attached to your skeleton.
     JURASSIC_THIGH = Action(
             "Apply a Jurassic Thigh Bone to your (Skeleton Type)",
             cost = Cost.ACTION.value + Cost.JURASSIC_FEMUR.value,
@@ -148,6 +152,8 @@ class Appendage(Enum):
             antiquity = 1
             )
 
+    # TODO: Base challenge: Narrow, Mithridacy 6
+    #       Difficulty increases by 1 for each limb that is NOT a KNOTTED_HUMERUS
     KNOTTED_HUMERUS = Action(
             "Apply a Knotted Humerus to your (Skeleton Type)",
             cost = Cost.ACTION.value + Cost.KNOTTED_HUMERUS.value,
@@ -157,6 +163,8 @@ class Appendage(Enum):
             amalgamy = 1
             )
 
+    # TODO: Base challenge: Monstrous Anatomy 4
+    #       No failure info on wiki
     OBSIDIAN_TAIL = Action(
             "Apply an Obsidian Chitin Tail to your (Skeleton Type)",
             cost = Cost.ACTION.value + Cost.OBSIDIAN_TAIL.value,
@@ -172,9 +180,11 @@ class Appendage(Enum):
             value = 250,
             tails_needed = -1,
             tails = 1,
-            implausibility = 1
+            implausibility = mean_outcome(1, 4, narrow_challenge(4, Char.MITHRIDACY.value))
             )
 
+    # TODO: Base challenge: Narrow, Monstrous Anatomy 1
+    #       Difficulty increases by 2 for each Fin already attached to your skeleton.
     TERROR_BIRD_WING = Action(
             "Add the Wing of a Young Terror Bird to your (Skeleton Type)",
             cost = Cost.ACTION.value + Cost.TERROR_BIRD_WING.value,
@@ -191,7 +201,7 @@ class Appendage(Enum):
             value = 250,
             tails_needed = -1,
             tails = 1,
-            antiquity = 1
+            antiquity = mean_outcome(0, 1, narrow_challenge(4, Char.MONSTROUS_ANATOMY.value))
             )
 
     UNIDENTIFIED_THIGH = Action(
@@ -202,27 +212,19 @@ class Appendage(Enum):
             legs = 1
             )
 
-    WITHERED_TAIL = Action(
-            "Apply a Withered Tentacle as a tail on your (Skeleton Type)",
-            cost = Cost.ACTION.value + Cost.WITHERED_TENTACLE.value,
-            value = 250,
-            tails_needed = -1,
-            tails = 1,
-            antiquity = -1
-            )
-
     WITHERED_TENTACLE = Action(
             "Put a Withered Tentacle on your (Skeleton Type)",
             cost = Cost.ACTION.value + Cost.WITHERED_TENTACLE.value,
             value = 250,
             limbs_needed = -1,
             tentacles = 1,
-            antiquity = -1
+            antiquity = -1,
+            implausibility = mean_outcome(0, 2, narrow_challenge(5, Char.MONSTROUS_ANATOMY.value))
             )
 
     REMOVE_TAIL = Action(
             "Remove the tail from your (Skeleton Type)",
-            cost = Cost.ACTION.value,
+            cost = Cost.ACTION.value * 1 / broad_challenge(220, Char.DANGEROUS.value),
             tails = -1
             )