Combined Casting: If two or more wizards cast the same spell at the same time, add 1/2 of the weaker affect roll(s) (rounded down) to the stronger/strongest one and use that as the overall affect roll.<br/><br/>Example: Charlie Weasely is trying to stun a small dragon using the stupefy spell, which dragons are very resistant to.  Knowing that he can't do it alone, he gets three other wizards to cast it at the same time.  They hold until all 4 are able to act and roll to hit.  Only 3 of them hit.  They roll a 15, 12, and 11 on their affect rolls.  The total affect roll would be 15 + (12/2) + (11/2), which equals 15 + 6 + 5, for a total of 26, far more than Charlie could have gotten on his own.