I imagine myself as a wizard with my staff and pointy hat, but the hat is too big and falls down over my eyes. What spells can I cast? Not many come to mind. Even teleport requires me to see where I’m going. I guess I can find familiar and use its eyes, but that’s not an example of the third case.You could, and that would allow for multiple options which - in this case anyway - exist:
You need line of vision AND line of effect
You need line of vision but NOT line of effect (if you can see the target point you're good, even if there's a transparent obstruction in the way)
You need line of effect but NOT line of vision (you can cast without seeing or even having a target point as long as there's nothing in the way)
You need NEITHER line of effect nor line of vision (you can cast into an unseen space, behind a wall, into the ground, etc.)

I’m not trying to be flippant. This is a situation that can be solved as the designer. One can define a range type for that effect, but in doing so, I want to imagine myself as the character in the game world, so I can convey it using language that would make sense as the character and to the reader having to interpret it.
It seems rather explicit in 5e that if you must target a creature “that you can see within range”, being blinded or in darkness would preclude casting a spell with that requirement. I’m not following how the terminology is being used incorrectly. The notation I’m suggesting wouldn’t change that. The only difference it’s standardized and presented in such a way to make it easy for the reader to scan when reading an effect’s description.The third of these is what always causes confusion, in that using "line of sight" terminology incorrectly implies you can't cast most spells while in darkness, or while blinded.
If I (as the designer) don’t want blindness to inhibit an effect with a RANGE, I can define it in such a way to do exactly that. I could say that blindness imposes a penalty, requires a check, etc on a RANGE- or SIGHT-based attack. Since those things are standard terms, there should be little confusion over when that should apply.
I’m certainly not suggesting rewriting what you have if it works for you! It just seemed like a very familiar solution. Adding it as another property lets you know at a glance something you consider important. It’s similar to what @AbdulAlhazred has been saying about capturing things like damage.My spell write-ups are in most cases long enough already, as I try to incorporate rulings, interactions with other spells, precedents, and so forth established over decades of play. They don't need the extra word count I saved by adding the L component (which is defined once, along with V, S, and M, in a separate 'introduction to spells' page).![]()
I’m generally erring more on the side of notation in the description for aesthetic reasons and also because I’m exploring ideas for my homebrew system. The format I posted in post #44 is highly WIP and not really meant for consumption. If I’m going to have to do the work of writing up and laying things out anyway, how should I like to do that? I appreciate the conversations I’ve had with people and the explorations of ideas for helping me work that out.