Focus

Focus is the resource that both Hunters and their pets expend to use their respective abilities. Focus is similar to the Rogue's Energy resource, in that it is a constant 100 points (105/110 with the Hunter Beast Mastery talent Kindred Spirits). By default the focus bar is full and when used, it regenerates fairly slowly (see below). The regeneration rate is not affected by being in combat.

Hunter

 * 6 focus per second, automatic. (see )
 * 9 focus generated using Steady Shot or Cobra Shot, 12/15 focus with Termination.
 * 50 focus instantly after casting Fervor.
 * 3 focus sometimes from Invigoration.
 * 6 focus per 3 seconds, casting Rapid Fire with Rapid Recuperation.
 * 25 focus instantly, when Rapid Killing is triggered with Rapid Recuperation.

Hunter pet

 * 5 focus per second, automatic.
 * Increased by 10/20/30% with Bestial Discipline.
 * 5 focus sometimes generated from Go for the Throat.
 * 50 focus instantly after casting Fervor.

Past implementations
During early stages of World of Warcraft development, Hunters themselves used Focus and it only regenerated when standing still. However, this distinguishing feature was dropped before launch.