Passive effects provided by any source other than a player's abilities are not affected by a player's active or passive abilities. In addition, most passive abilities cannot trigger other passive abilities.

Example:
A Signet that a player has equipped provides a barrier when a player lands a critical hit. This barrier will not be affected by any of a player's equipped passive abilities that modify barriers because the barrier is provided by the Signet. This barrier will also not be applied if an equipped passive ability or damage over time effect critically hits.