Unfortunately this rule creates bookkeeping, which I would pass on to the players.

Say you have 20 wounds. You're hit and take 5 wounds. Your Apothecary tries to First Aid you and fails his test. That was an attempt to treat those wounds, which was not successful.

You are then hit for 5 more wounds. Your Apothecary tries to First Aid you and succeeds. It turns out he can restore 10 wounds because of his skills etc. However he can only restore 5 of those 10, because your most recent 5 wounds were untreated (and could be healed with First Aid) but the previous 5 wounds were attempted to be treated before, so they cannot be attempted to be healed again with First Aid.

Yes, this creates a need to keep dumb records. Add to it that you can always spend Fate to heal wounds and doing so does not interact with the treated/untreated dichotomy. If you take 15 wounds and spend a fate to heal 1d10 and get a 7, you can keep spending fate to heal up the rest of that 10, to the limit of your fate for the session.

I find the more serious problem to be First Aid taking up only 1 Full Action. That's like 10 seconds out of combat. We've changed it to require 15 minutes out of combat time otherwise there is no way the team will be running around wounded and will be at full wounds for every fight, in all likelihood, and it makes the choice to stop and heal up more tactical if they're running on a timer.

Thank you for taking the time top explain, but you seem to be proceeding from the premise that Wounds are a thing a character suffers or loses. This seems to be a common misconception with the game, perhaps because of the way hit points work in common fantasy RPGs like Dungeons & Dragons and Pathfinder.

In actuality, Wounds is a threshold, and the characters suffers Damage. The Wounds threshold indicates how much Damage the characters can suffer before suffering Critical Effects along with the Damage.

15 minutes seems quite a lot to me, as long as there is no critical damage. Applying some spray-on skin or bandages doesn't take that long. Even more if you're a ******* Apothecarius!

Kshatriya is correct, and I like the idea of the time frame, mostly.

Well Avdnm, it is kind of hard to spray on fake skin or apply bandages when you have a self enclosed rigid ceramite plate between you and the wound. Granted space marine blood makes its own spray-on skin and practically alleviates the need for bandages, but when you want to get to that injury to make sure you are sewing the marine's muscles back together "the correct way" before they heal incorectly. Well in that case, you gotta take off that armor man.

15 minutes seems quite a lot to me, as long as there is no critical damage. Applying some spray-on skin or bandages doesn't take that long. Even more if you're a ******* Apothecarius!

Personally I like a bit more threat than every character starting every battle at full health. Which is how things go with the RAW.

Thank you for taking the time top explain, but you seem to be proceeding from the premise that Wounds are a thing a character suffers or loses. This seems to be a common misconception with the game, perhaps because of the way hit points work in common fantasy RPGs like Dungeons & Dragons and Pathfinder.

In actuality, Wounds is a threshold, and the characters suffers Damage. The Wounds threshold indicates how much Damage the characters can suffer before suffering Critical Effects along with the Damage.

I don't know what you'e trying to say, but it seems to be a comment on game meta-design. Regardless, what I posted is how healing of non-critical damage with first aid is implemented per the RAW.