Your RPG StackExchange answer admits near the end “[…]as written, Tricksy Darkness has no effect because it doesn’t explicitly mention preventing nonmagical illumination, it’s logical to assume that it was intended to do something[…]“ The assumption that it should do something is the basis for the author’s claim that it blocks non-magical light.

Magical darkness behaves exactly like normal darkness in 2014 5e and 2024 5e, unless other rules modify its behavior. By default, it doesn’t block line of sight, darkvision, magical light, or even non-magical light unless something specifically says it does, like in the darkness spell for instance.

That all said, Tricksy wouldn’t do anything if it didn’t block nonmagical illumination, so it’s reasonable to run it as though it does.

That’s my point. It never says it blocks even non-magical illumination, so therefore, does functionally nothing.

And running it as though it doesn’t block nonmagical darkness results in nonsensical behavior. You’re in a torchlit chamber and use the ability - now there’s a cube of darkness, blocking the light of all four nonmagical torches.

You’re in a torchlit chamber and use the ability - now there’s a cube of darkness, blocking the light of all four nonmagical torches nothing. Just illuminated by torchlight until a rule update does something other than make it bigger to fix the issue.

But Umbral Sight works with normal darkness too, and if it doesn’t prevent magical or non-magical light from illuminating it, people don’t have to rely on darkvision to see them in that magical darkness (if it’s illuminated by anything). At least the Hallow darkness effect prevents illumination, so that does work for Gloom stalkers, but this is quite literally useless.

Hiding the spell and the action it takes are kind of superfluous to the jumping rule that says “[…] each foot you clear on the jump costs a foot of movement.”

Update: We finished the campaign last night on Friday the 13th (9/13/24). We all got out alive, with the majority of our loot, from the 23rd level, at level 19 (334411 XP 😁), but opted not to fight Halaster in the condition we were in.

All the information is on the task.

But you’d have to go outside the walls to get to the turrets. And you’re in a situation where you have someone who can cast 8th level spells. I’m not sure this advice is sound. 🤨

You don’t even need to homebrew. Spell scrolls exist. It’s not unreasonable to think a spell scroll of mighty fortress would be stored away for safekeeping somewhere for a long time before the PCs find it. 👍🏻

Still better than the 50,000 gp construction cost and 400 days for a “Keep or small castle” using Building a Stronghold. Actual time spent on labor amounts to a minute per week for a high enough level wizard.