small change to make heavy armor mastery feat viable at higher levels

[Malifice]

For ease of use, I actually just have it apply to all attacks. subtracting 3 damage from everything is almost nothing from Dragon's Breath or a high level spell, but outright shuts down a lot of attacks from Goblin archers or Kobold Slingers.

Its already a strong feat.

Saving 3 damage from each incoming B, P and S attack is pretty huge.

Over the course of your [6 encounter/ 2 short rest] adventuring day, thats a ton of saved HP. Its more than you get from the Tough feat that grants +2 HP/ level.

Tough at 10th level is what... 20 extra HP? HAM at the same level will save you over 60 HP over the course of your standard adventuring day, presuming you get hit around 20 times in 6 encounters (3 attacks hit you per encounter).

Dont forget HAM also grants +1 to Strength as well.