Ironshank

is an illness that is diagnosed by the initial feeling of stiff legs and aching joints, and the leg bones will have increased growth and calcification, severely restricting movement. can be contracted by drinking, cooking with, or falling into. Many creatures that are made of or use as a form of attack can also make the player contract, such as ,  tripping the player character into a puddle of it, or  spewing the liquid at the player character using Bilge Sphincter.

Onset
After the initial contraction of, there is a check every day (1,200 game ticks) afterwards. The creature must make a toughness saving throw with difficulty 13. This means that a 20 sided dice is rolled, with the modifier for toughness added on to the result. This must be greater than or equal to 13 to succeed. If this roll succeeds, the stage of onset will decrease by 1. This has succeeded if the message "You feel a bit better." appears. Else, the message will be "Your legs ache at the joints". The initial stage of onset is 0. If the stage successfully reaches -2 (two successful saves in a row), the creature has shaken off the without further complications.

If the total stage reaches 3, or the total amount of days infected with reaches 5 (6,000 in game ticks), the creature will gain full blown.

Prevention
Aside from having a larger Toughness modifier to help against the saving throws, the infected can consume either, , or. This adds an additional +2 bonus to the saving throw. Using both will not stack the bonus. However, consuming a recipe that has +3 to disease saves as an effect does.

Full Infection
After a full contraction of, after every 4 days (4,800 in game ticks), the creature will lose 6-10 Movement Speed, and gain AV of the current total penalty divided by 15, rounding down.

If at the max -80 Movement speed penalty this message is displayed instead:

At this point, the creature will have a total bonus of 5 AV.

It is possible to fully offset this movement speed bonus with Level 4 Multiple Legs.

Curing Ironshank
Curing must be done according to the, which is to drink a a mixture of , which is desalinated , and a randomly generated liquid. This must be drank from once a day (1,200 in game ticks). The proportions are not important, so if one liquid is hard to come by it can be "diluted" by making the cure one dram one liquid and the rest the other liquid.

The randomly generated liquid will be chosen to be either:
 * Blood
 * Honey
 * Wine
 * Oil
 * Asphalt
 * Sap

Drinking the cure is successful if "The pain in your joints subsides." appears in the message log.

The Movement Speed penalty will decrease by 6-10, with the AV bonus decreasing to match. Once the penalty reaches 0, the player character has fully cured. Curing this grants the Footloose achievement.

It is possible to put off fully curing to keep the AV bonus but keep the movement speed penalty to manageable levels.