Level Up (A5E) Adept - Brutal Defense

[Steampunkette]

And, of course, all of this separate Flaw-based issue also requires:

1) A Critical Hit to be landed with a piercing weapon. (1 out of 20, 1/3rd of weapon attacks, so 1/60th of attacks or less depending on enemies)
2) The Player and/or Narrator remembering the Flaw rule that one time.
3) The table actually following through with that rule rather than just ignoring it.

'Cause people make mistakes in TTRPGs all the time, or ignore rules they don't particularly like.

 

[lichmaster]

And, of course, all of this separate Flaw-based issue also requires:

1) A Critical Hit to be landed with a piercing weapon. (1 out of 20, 1/3rd of weapon attacks, so 1/60th of attacks or less depending on enemies)

Or more, considering advantage. Plus, the chance not to be critted decreases relatively quickly when you're attacked several times.
I can see level 4-5 characters being peppered by many arrows from goblins, and quite some armors piercing this way

2) The Player and/or Narrator remembering the Flaw rule that one time.

I think this is also a matter of how the information is presented.
I relly love LU, but I feel a lot of small but interesting rules like this one are a bit scattered sometimes.
For example, this thing of the armor breaking when being critted or crit failing a save if the armor has this flaw should be mentioned in the combat chapter, under Critical Hits and Fumbles and in the Saving Throws paragraph of the Ability Scores Chapter, but they aren't.