This page covers a general game mechanic and a widely used game term, and is not itself a specific player ability.
A Knock back (also known as punting) is in general the ability to lift and knock a character backwards away from a combatant some distance, even possibly quite far. Before patch 3.3 WotLK, receiving a knock back could also cause a player to become dismounted from their ground or flying mount.
Player's abilities which emit a knock back effect can either knock an enemy or yourself backwards a certain distance. In some cases, as with hunters Disengage when out-of-combat, will also cause the player to dismount. Historically, the ability to 'knock back' is one that was only given to some mobs or NPCs (Non-Player Characters) as a special ability, with rare exceptions such as Disengage. They were sought after by players in the past and were implemented in Wrath of the Lich King as a more pervasive feature of many more abilities for other classes and races. If you have knock back effect, use it wisely. For example, Hunters benefit from the extra range the knock back gives them.
Player abilities with a knock back effect:
- Hunters's talent Disengage: 13 yard "self" knock back, considered similar to blink. As of Patch 5.4, disengage can be used out of combat.
- Shaman's talent Thunderstorm: 20 yard knock back. Theorically, this spell has the most powerful knock-back.
- Mage's talent Blast Wave: between 10 and 15 yard knock back. As of Cataclysm no longer emits a knock-back effect.
- Patch 5.4.0 (10-Sep-2013) Hunters can now use Disengage out-of-combat.
- Patch 4.1.0 (26-Apr-2011): Mage Blast wave no longer causes knock back.
- Patch 3.3.0 (08-Dec-2009): Knock back effects no longer dismount players. If on a flying mount, you will be knocked back a short distance before being able to resume flying.
This is likely due an abuse of player knock back abilities in PvP to causing flagged players to fall to their death.
- Patch 1.6.0 (12-Jul-2005): Knock back effects are now synchronized with any associated missile impacts.