Barrier Decay Threshold
From Titan Quest 2 Wiki
Barrier Decay Threshold in Titan Quest 2 (TQ2) refers to the amount of Barrier that remains after using the Barrier Skill and it has fully "decayed". 3 seconds after using Barrier it will begin to decay, at a rate called Barrier Decay Rate, until there is no Barrier remaining. However, if you have any amount of Barrier Decay Threshold, instead of it draining to "0" it will drain to the number of Barrier Decay Threshold, preserving some Barrier.
Titan Quest 2 Barrier Decay Threshold Guide
There are not many ways to increase your Barrier Decay Threshold in Titan Quest 2, but there are some. Below is a list of ways:
