Play
The players have split up briefly. Moss has just been in lone combat, driving a mighty newt back into the river.
Ref: Okay, if you’re taking a moment to rest you can restore your Guard back to full. That Vigour loss will be harder to recover.
Moss: Oof. That thing took away like 4 of my with one bite. VIG
Ref: Wait… Hang on. Your max is 6 VIG right? If you lost half of that in one Attack it should have been a Mortal Wound.
Moss: Oh. Well, I’d probably be dead right, since Tal wasn’t around to help me?
Tal: We can say Tal showed up to help?
Ref: You know what, I don’t think we should go back and change things. The combat went the way it did, we’ll just make sure we remember next time.
Moss: Aah, I dunno, I feel bad. Feels like I’ve cheated.
Tal: I don’t feel cheated!
Moss: No I mean like I should be dead. I want things to be fair.
Ref: But you probably would have used the Deny Feat to block the Damage if you’d known, right? I think the end result would be the same. Not like you came out without a scratch. If it’s really important then we can roll back and redo the combat. Maybe just go back to right before you took that bite?
Ref scrambles through their notes to try to work out who had taken Damage.
Moss: No, no, you’re right that feels dumb. As long as you both know it was an accident.
Ref: Yeah of course. Hey, first excuse I get this newt is coming back to finish the job.
Thoughts
This is going to happen. You might notice immediately, or you might realise months into a campaign that you’ve interpreted a rule differently than the book intended.
The important thing is that you look back and ask yourself what harm has been done.
In most cases the game will have worked just fine. Maybe things will feel better when you start using the correct rule, but I’d warn against going back to change the past, even if the consequences would be severe.
When this happens in plain view of the group you can encounter Moss’ reaction here. Some players won’t mind, or might enjoy that they got away with something, but others can feel that the reality of the game world has somehow been compromised.
Ref handled it pretty well here, explaining that the situation wouldn’t be all that different with the correct ruling. I think they were right to offer to roll things back for Moss, but I’m also glad that Moss didn’t take them up on it. I’m not sure what would be gained by repeating the combat.
But what if the opposite had happened. What if Moss had been killed by the newt, but later realised that the correct rule would have had them live? This is a more difficult situation to manage. Here I’d lean on the principle of being generous to the players, but try to do so without completely invalidating the play that’s already happened. Perhaps Moss was dragged into the water, assumed to be dead, but re-emerged days later. If Moss had already created a new Knight, perhaps that character becomes a non-player character, being a new contact in the Realm.