Some spells allow the Wizard the option to focus more magical force into their casting, thus extending the effective range, amount of damage caused or area of effect. Where this is an option, it is clearly stated in the spell's effect, as is the extra casting cost required to achieve the additional effect.

If you roll high enough so that the casting value of the boosted version of the spell is reached, you may choose whether or not you want to cast the standard or boosted version of the spell.