[Neo the Warrior Cat]

The name of the spell you are referring to, IIRC, is Nahjal's Reckless Dweomer.

It says in the spells description that it deliberately creates a wild surge wich your mage then tries to shape into the desired spell. Since it is a planned surge your spellcasting level plus the bonus from the Chaos Shield spell are added to the wild surge roll. There are 100 different outcomes to this roll. So use carefully...