Whenever a Chaos Dwarf with this special rule suffers a Miscast during the game, after resolving the effects of the Miscast on them normally, they must take a Toughness test. If this is failed they suffer a single additional wound which may not be prevented in any way (even by ward saves etc). However the first time they suffer a wound in this manner, they also gain a bonus of +1 Toughness for the rest of the game. Subsequent failures simply cause additional wounds to be inflicted instead.