Correct about the any damage wording. The problem is that Babau demon slime damage by the RAW rules can not hurt an average non-magical longsword. Let along a magic longsword.
By RAW acid damage vs objects is half damage and it only does 1d8 damage to start with. Metal starts at hardness 10 which reduces elemental damage like DR. So even if NOT half damage the slime could not hurt the weapon anyways. LOL
I assume most DMs play it that its not half dmg and bypasses hardness. IMHO the most was is full damage and it treats weapons as half hardness leaving Adamatine immune. But its not what it actually says in the statblock.
Sorry couldn't resist as it came up during the RotW AP.
Well...technically there is still some RAW wriggle room...
"Energy attacks deal half damage to most objects. Divide the damage by 2 before applying the object's hardness. Some energy types might be particularly effective against certain objects, subject to GM discretion."
I would be such a GM that would rule the slime as being effective against metal and wooden weapons, given you get a save and the hardness still.
So ya, there's no straight forward calculations you can do. But I suppose you could still impose a "Broken" condition automatically as there is already an broken adjustment that you can apply earlier if needed?
Unless someone has an example where a weapon would NOT be broken at half-damage? So far I think it's only half-damage or earlier.
