Out of curiosity, what exactly is the difference between 'BS' and 'difficult'? All attacks with an element of randomization will have will depend a tiny bit on luck to some degree. I've had a few moments where DDBB trapped me, but mostly it's just an extremely hard and confusing card.
And also, isn't Trauma in the Glimmering Depths static? I know the MoF version is, unless the Recollection version completely changes it up.
BS = factor which modifies difficulty.
Consider the difficulty a base, C.
When I say "It's more BS than difficult", I mean that luck is more involved than what it should really be.
Overall difficulty can be considered being a relation between the two, say
OD α (C ? BS).
i.e. overall difficulty is proportional to a base difficulty, give or take a "luck" factor. Some cards have a higher degree of "BS" than others. And the longer the card goes for, the larger the luck factor is involved (usually). An example is Eternal Meek throwing a high speed wall at me from the start of the card, shaped "∩". Contrast with... BoWaP. Static. Fixed difficulty.
Recollection "Trauma in the Glimmering Depths" is (partial) static I believe. But it's so
damned hard to navigate. I can never position myself correctly, and even if I could, I have an absurd chance of clipping a bullet.