The Blade Mastery feat says this:
You master the shortsword, longsword, scimitar, rapier, and greatsword. You gain the following benefits when using any of them:
- You gain a +1 bonus to attack rolls you make with the weapon.
- On your turn, you can use your reaction to assume a parrying stance, provided you have the weapon in hand. Doing so grants you a +1 bonus to your AC until the start of your next turn or until you’re not holding the weapon.
- When you make an opportunity attack with the weapon, you have
advantage on the attack roll.
Its second feature says that using your reaction, you can get a +1 bonus to AC. This lasts until you're not holding your weapon. Does this mean that in multiple consecutive rounds you can use your reaction to get a +1 bonus as long as you're holding the weapon, which could (theoretically) allow you to have, for example, +6 to AC after a minute like this? Or can the bonus only apply once, RAW?
Best Answer
This is playtest material, so the wording isn't always as hammered-out as we hope final material is, but... I think you're reading the text wrong. It says:
... which you interpret as "the benefit lasts as long as one or the other is true". I can see that. There's another possible interpretation which I believe is the intention: "the benefit ends when one of these things happens". English has an ambiguity around the word "or", leading to both interpretations matching RAW — but personally I think it's pretty clear which is meant. And this is supported by the first part of the description: you're able to assume a parrying stance provided you have a weapon in hand.
One could read this as a requirement only to start such a stance (because it says "assume"), but I think it's pretty obvious that the intent is to require a weapon in hand the whole time.