Magic

In Rokugan, magic is a very real thing. Spirits of the elements dwell in everything and shugenja are trained to get the spirits to do their bidding. In addition, monsters stalk the lands, and society is keenly aware of the Shadowlands, where nightmares walk about in putrid flesh.

Dangers of Spellcraft
Not every spell is cast perfectly. Usually, failed incantations merely have no effect, but sometimes, the kami are angered and lash out. All sorts of disasters are possible if this should happen, one of the most devastating being the shugenja being driven mad. Most in this situation are unstable for the rest of their lives, scarred in one of the elements. Each time that shugenja casts a spell from that particular element, he stands a chance of losing control of himself. (Phoenix p. 52)