If it fits your world…go for it!!!
But, I like that rule. Only a true defense expert will have 10 versions of this between long rests, and a semi-defense expert will have 3…
It increases the value of Con a bit too much, however I love surge dice and this acts similar but only for defense.
If you’re to adjust it a tad, it would fit for a low/high fantasy where the hero’s survive more than expected.
Add these 4 points to all, and they can send them to other players if fighting enemies…but those who use effort points get more than 4 or certain classes get more.
Or if blessed you’re get 1 for the next d4 rounds.
It seems small but it’s not. It is surprising what X for the next D4 rounds can change the survivability of the game becomes.
If Shadows affect only self, but healer types affect only others…or all others in close…or near, it really affects the survival of the party.
It also ties everyone to their roles.
It’s a small thing that provides a huge difference.