Text (TE+errata): ~this~ deals X damage divided as you choose among any number of target creatures and/or players. [Oracle 1999/05/01]
X can be zero. [D'Angelo 2003/05/19]
If X is greater than zero, you cannot choose zero targets. You must choose between 1 and X targets. If X is zero, you cannot choose any targets. [DeLaney 2003/05/19]