Iron Body is an exercise used to strengthen your body against all kinds of blows. Common techniques include slapping your body at least 200 times a day, and increasing the force of the blows every few days. After your body builds up the resistance, you switch to punches, and after that to bags of beans, gravel or even metal. It may take years for the exercise to be complete, if this is a thing that can be ever completed -- you can always become more resilient, more durable.

For most part, this skill is a passive skill. You only gain the passive benefits of this skill when unarmed. Wisdom only affects the active use of this skill. Actively using this skill does not affect the passive use in any way.