Multistrike

Multistrike was a secondary attribute introduced in Warlords of Draenor that provided a chance for spells and abilities to fire up to two additional times, at 30% effectiveness (both damage and healing).

In PvE, character spells and abilities had two chances to deal an additional 30% damage. Each hit could offer up to 100% + 30% + 30% = 160% total damage.

In PvP, character spells and abilities had one chance to deal an additional 30% damage. Each hit could offer up to 100% + 30% = 130% total damage. Multistrike was exactly half as valuable in PvP, point for point.

For example, a character might cast a Frostbolt against its target, hitting for 1000 damage, and then score a multistrike, causing a second Frostbolt to hit the target (with no additional mana cost or casting time) for 300 damage. In other words, sometimes the ability would hit just once for normal damage; sometimes it would hit twice, with the second hit dealing 30% damage; and occasionally it would hit three times, with the second and third hits each dealing 30% damage. Multistrikes didn't "Double dip" into stats like Versatility or Mastery, so if a character had 10% Versatility and their Frostbolt hit for 1100, the Multistrike would hit for 330 (as apposed to 363 if it gained the benefit twice).

Multistrikes crit independently of the main attack. That is, the main attack did not have to crit in order for the multistrike to crit. As seen on the attack table, assuming the character currently had 20% crit chance and 10% multistrike chance, each multistrike roll would look like this: