Meditation Skill
After a short training period your Meditation skill will reach 100 with no real effort. You do not need to train this skill actively, because it goes up on its own while your mana regenerates.
Meditation passively affects your mana regeneration rate.
Meditation is also an active skill. Activate it from your skill list and you will start meditating. While meditating, your mana regenerates faster than normal. Any movement (such as walking) or someone attacking you will break your concentration and stop the meditation.
While meditating you cannot wear metal, scale, studded or bone armor. Only cloth and non-studded leather can be worn. Leather and cloth are known as "medable" armor. There will be times when you want to use non-medable armor, but even if you are wearing 5 pieces of medable armor, a single piece of non-medable armor ruins the whole thing and your entire suit is treated as non-medable.
Non-medable armor affects both active and passive meditation. Wearing non-medable armor lowers your mana regeneration rate.
Keep in mind that metal, scale, studded and bone armor is medable if it carries the "mage armor" property. Also, while you are actively meditating, your weapon and shield will be automatically unequipped unless they have spell channeling.