FOES AFFECTED BY AREA ATTACKS
*Substitute a d24 if one is available.
Adjust the number rolled based upon foe size. For example, double the number affected if the foes are small and divide the number rolled by 4 for large numbers.
At the DM option specifying a particular target in a group ('I center the effect on the wizard') bump the dice range one category to the left. Crowded groups are treated as average density and average groups as sparse. Half the numbers rolled for sparse groups.
The special 'vs PCs' column is designed to take into account that most players are smart enough to avoid crowding up against a dragon or fireball-lobber. A DM could probably get away with occasionally using this column for tactically-minded NPC groups.