Abilities that Impair and Hinder enemies in The Secret World are reduced in duration when they are applied repeatedly to same enemy target. The mechanic of Impairs and Hinders losing duration is referred to as "diminishing returns.” Impairs and Hinders suffer diminishing returns independently of each other, meaning that a target that has been recently impaired will still suffer full duration hinders, and vice versa.

Whenever an Impair or Hinder is applied to any target (players or non-player characters) a 15 second effect is also applied to that target that will reduce the duration of any sequential state of the same type by 34%. This effect stacks additively when multiple abilities that apply the same state are used on the same target. A target that has been recently affected by two of the same type of negative states will be protected by an effect that will reduce the duration of any sequential effects of the same type by 68%. A target that has been recently affected by three of the same type of negative states will be protected by an effect that completely negates any sequential negative states of the same type.

Example:
Player A encounters Player B in PvP and impairs Player B with Stunning Swirl. Player B is impaired for three seconds. Two seconds after Player B recovers from Player A's Stunning Swirl, Player C arrives and uses Domino Effect on Player B as well. Because 15 seconds have not passed, the normal duration of Domino Effect's impair will be reduced by 34%, making it only last 1.98 seconds. After another second passes, poor Player B is then attacked by Player D with Slow the Advance. Since the diminishing returns applied by impairs are not shared by hinders, Player B will be hindered for the full 8 second duration.