Please help me workshop some changes that I'm making to Hide and Invisible. Fundamentally, I'm trying to provide more codification to aspects that seem far too vague to be of use right now. Specifically, I do not like the fact that it confers the "Invisible Condition" with the very vague fail state of "being found", or that a player can't simply "stop being hidden" if the list of fail states is treated as exhaustive. I decided on a different condition, called "Unseen" (or, perhaps "Hidden"?), that magical invisibility also confers, and has the same benefits as the current Invisible Condition. The Invisible Condition, by extension, gets all of those benefits as well as actually being Invisible to the naked eye (strangely, that doesn't seem to actually be a part of invisibility). The main benefit of Invisible, then, is to be able to move out into the open and remain unseen until Invisibility somehow wears off.

This unseen/hidden condition is similar to "Frightened" in that you can have the condition against some creatures, but not others, and the benefits of being Unseen are only against those creatures who treat you as having that condition.

The main things I'd want to have happen are:
1. Someone who is hidden cannot be targeted by attacks, spells, or effects that require line of sight.
2. Someone who is hidden gains advantage on attacks against creatures they are unseen to. They lose the unseen condition once the attack hits or misses.
3. Someone who is hidden gets advantage on initiative rolls when combat starts.
4. Someone who is hidden will lose this condition if they do any of the current listed things in the Hide Action, in addition to simply deciding not to be hidden any more.
5. Someone who his hidden uses their Hide Roll as a DC against the Search Action to find them, but only if the searcher is in a position where the hidden creature is not in total cover.
6. Someone who is hidden can leave cover on their turn and keep the unseen condition against other creatures unless one of the following happens:
6a. An attack they make hits or misses.
6b. They end their turn outside of 3/4 cover, full cover, or heavy obscurement.
6c. They cast a spell.
6d. They make a sound louder than a whisper.
6e. A creature has a passive perception score above their DC set by the Hide Roll.

Essentially, I want rogues to be able to attack at range while hidden for advantage (and sneak attack), and also to be able to sneak up on someone, as long as they do it quickly (within the turn) and somehow remain unseen until they attack (beat the passive perception of the victim), and also dart from cover to cover. But I don't want them to be able to make a single roll, then walk around in broad daylight flapping their arms around like idiots and somehow remain "Invisible". They would actually need magical invisibility to do that.

Here is what I've come up with:

Invisible [Condition]

While Invisible, you are completely transparent and cannot be seen by ordinary sight.

You automatically have the Unseen Condition to creatures that rely on sight unless they can perceive invisible creatures through a special sense, magical effect, or similar feature. The Unseen Condition cannot end on you unless the Invisible Condition also ends.

Unseen [Condition]

A creature can be Unseen to some creatures but not others. Whenever a rule refers to a creature being Unseen, it applies only against creatures for whom the condition exists.

While Unseen to a creature:

Concealed: You cannot be targeted by attacks, spells, or effects that require the creature to see you.

Attacks Affected: You have Advantage on attack rolls against that creature and attacks against you from that creature are made at Disadvantage.

Surprise: When combat begins, any enemies that you are Unseen to have Disadvantage on their Initiative Rolls. If you are Unseen to all enemies when combat starts, you also have Advantage on the Initiative Roll.

Moving While Unseen: Being Unseen does not require you to remain stationary. It is possible to move out from behind cover or obscurement and remain Unseen. See below.

You cease being Unseen to a creature if any of the following occur: you choose to stop being Unseen and the creature can reasonably perceive you, you make an attack roll against that creature (when the attack hits or misses), you cast a spell with a Verbal component, you make a sound louder than a whisper, an effect explicitly reveals your location, the creature successfully finds you using the Search action, your turn ends while you lack Total Cover, Three-Quarters Cover, or Heavy Obscurement from that creature, or the creature's Passive Perception equals or exceeds your Hide DC while you are outside of Total Cover, Three-Quarters Cover, or Heavy Obscurement.

A creature can cease to be Unseen to one creature without ceasing to be Unseen to others.

Hide [Action]

With the Hide action, you try to conceal yourself. To do so, you must succeed on a DC 15 Dexterity (Stealth) check while you’re Heavily Obscured or behind Three-Quarters Cover or Total Cover to at least one perceived enemy.

On a successful check, you have the Unseen Condition to all creatures for which the prerequisites of taking the Action apply. Make note of your check’s total, which is the DC for a creature to find you with a Wisdom (Perception) check.

A creature cannot use the Search Action to locate you if you are behind Total Cover relative to that creature.

 
Now, I'd like to reduce the amount of words, if possible, and I think I can do so in the "ways to end Unseen" part (and I'm not sure if the Moving While Unseen bit is necessary), but I'm also struggling a bit with Surprise and whether I want things like casting a spell behind total cover to end Unseen or not. Thoughts?