You deflect all attacks and take 30% less damage for 5 sec, but you cannot attack.
Deterrence is a hunter ability learned at level 78. For five seconds it enables the hunter to escape melee, ranged, and spell damage and also reduces damage taken by 30%. While unable to attack, the hunter can use traps, non-damaging abilities, command their pet, and also use [Kill Command].
0500Patch 5.4.0 (10-Sep-2013) Deterrence now has a 3-minute cooldown (up from 2 minutes) but has 2 charges.
0400Patch 4.3.2 (31-Jan-2012): Deterrence now also reduces damage taken by 30% while active.
0400Patch 4.1.0 (26-Apr-2011): Deterrence no longer requires a melee weapon to be equipped.; The area damage of the paladin ability Hammer of the Righteous will no longer hit hunters with Deterrence active.
0400Patch 4.0.6 (8-Feb-2011): Deterrence now provides 100% chance for melee attacks to miss instead of 100% parry chance. This means that attacks that cannot be parried, notably some rogue abilities, can now be prevented by Deterrence, and the hunter will gain the benefit of Deterrence even if disarmed.
0300/0400Patch 4.0.1 (12-Oct-2010): No longer a talent, now available to all hunters.
0300Patch 3.3.0 (08-Dec-2009): Now also increases the chance for ranged attacks to miss the hunter by 100% while under its effect.
0300Patch 3.2.0 (04-Aug-2009): This ability now allows the hunter to parry spells and attacks from behind as well as in front. Now has a new visual spell effect.
0300Patch 3.0.8 (2009-01-20): Design changed to grant 100% parry and 100% chance to "deflect" spells coming from the front, but prevents the Hunter from attacking. Lasts 5 sec. 90 sec. cooldown.
0200/0300Patch 3.0.2 (14-Oct-2008): Cooldown reduced to 3 minutes, and now also increases your chance to resist spells by 60%. Now has a new spell effect.