Automatic reduction to 0 hp on a critical hit

[TheShadow]

Is it possible to create a trait for an NPC that when it is hit by a crit it automatically drops to 0hp? This is a homebrew variation on minions that I would like to automate but I am not sure it is possible in 5E FG.

[LordEntrails]

No such trait in regular FG. But it is possible for you to create an extension that would support such a trait.