Bounce

Bouncing is a property of some skills which allows them to hit enemies after their initial target. Unlike piercing attacks, bounce is not limited to targets in a straight line.

Bounces are consumed for each target after the initial target. For example, a skill with 1 bounce can hit up to 2 targets. 2 bounces hit up to 3 targets, etc.
Skills can bounce to the same foes/allies multiple times (i.e. a skill with more than 1 bounce can bounce between 2 targets multiple times, such as foe 1 to player 1 to foe 1 to player 1, etc.).
Skills that can bounce between foes & allies may bounce between foes or allies consecutively and may bounce only between foes or allies
The target of the bounce is typically the closest valid target
The range of the bounce may be shorter than the range of the initial skill
Skills can bounce even after the target is defeated if the skill was cast when the target was valid.
The speed of the bounce projectile appears to be based on the speed of the initial skill (fast attacks = fast bounces, slow attacks = slow bounces). It is thus easier to evade slow bouncing attacks.
Some skills may not bounce to the same foe if it was already hit by the skill (e.g. Magic Bullet).
If there are not enough valid targets, then the additional bounces are wasted.
Bounces may be reflected