Pets set to Assist will attack any target that its master attacks. Attacking a new target will cause the pet to switch to that target after a few seconds. The Assist stance also incorporates the Defensive pet stance; pets set to Assist with no current target will attack any target that attacks itself or its master.
Pets in Assist will not register their master's attack until the attack itself is completed; it is usually preferable to manually command the pet to Attack before the cast is complete, especially when opening with abilities with a long cast time (such as ), or if using the pet to tank.
Assist was introduced in Patch 4.2, replacing Aggressive. Although less dangerous than its predecessor, Assist is still hard to control. Pets set to Assist cannot reliably be made to attack a specific target other than that of the player; they will always switch to the player's current target, even if repeatedly commanded to Attack another. This can be problematic when dealing with multiple enemies, such as when quickly dealing with adds while mostly focusing on a more important target. This can be particularly disadvantageous for melee pets, causing them to waste much time running from one target to another. Setting the pet to Defensive (or Passive) is often preferable in these situations, allowing the player to focus the pet upon a specific target. As with Defensive, pets in Assist with no current target will immediately attack any target that attacks it or its master, which can be problematic in instances.
When soloing, Assist can be useful for causing the pet to immediately assist the player in attacking their current target, although using the Attack command is still quicker and more effective, especially when using the pet to tank.