Saving Throws and Damage

Damage dealt via saving throws uses these rules.
Damage against Multiple Targets
When you create a damaging effect that forces two or more targets to make saving throws against it at the same time, roll the damage once for all the targets. For example, when a wizard casts Fireball, the spell's damage is rolled once for all creatures caught in the blast.
Half Damage
Many saving throw effects deal half damage (round down) to a target when the target succeeds on the saving throw. The halved damage is equal to half the damage that would be dealt on a failed save.