The Armorer Artificer's Arcane Armor feature says:
If the armor normally has a Strength requirement, the arcane armor lacks this requirement for you.
This is in reference to the following regarding certain heavy armors:
If the Armor table shows "Str 13" or "Str 15" in the Strength column for an armor type, the armor reduces the wearer's speed by 10 feet unless the wearer has a Strength score equal to or higher than the listed score. [PHB, pg 144]
However, the Encumbrance variant says, in part:
When you use this variant, ignore the Strength column of the Armor table in chapter 5.
If you carry weight in excess of 5 times your Strength score, you are encumbered, which means your speed drops by 10 feet. [PHB, pg 176]
Is there guidance for how to apply the Arcane Armor feature at a table that uses the Encumbrance variant?
Best Answer
Since encumbrance is a variant rule, the book does not cover how it would interact with Arcane Armor.
In the absence of an official rule, it'll be up to your DM to make a decision.
If I were the DM here, I'd probably just rule that the weight of the Arcane Armor doesn't count against your encumbrance limit when you're wearing it -- it's basically power armor, so it's logical that the armor's enhancements allow it to support its own weight and inertia. That seems like the simplest rule, and in line with the original intent of removing the strength limit.
That said, I personally don't care that much if one of my players can lug around an extra twenty pounds of stuff, but a DM who's using variant encumbrance probably cares a lot about the fine details of how much you can carry. So he may be more willing than I am to delve into complicated rulings about how the class feature operates.