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?

Id change unseen[condition] to concealed[condition]

And then change "Concealed: You cannot be targeted by attacks," to "Hidden: You cannot be targeted by attacks,"

Also, no mention of passive perception....

A flat dc 15 suggests to me that the passive perception doesnt apply to hiding, but everyone seems to say it does.

I'm not sure if "concealed" gives the right connotation for the condition itself, but I'll think on it.

As for Passive Perception, I do mention it, but only as a way of avoiding someone actually sneaking up on you during their turn while out of cover.

I'm trying to thread the needle by allowing rogues to use one of their defining fantasies while also not allowing it to be a resourceless Invisibility spell.

Quote from sabin76 >>

I'm not sure if "concealed" gives the right connotation for the condition itself, but I'll think on it.

it's just a pet peeve of mine. The rules were written by someoen who did not know the clear difference between Cover versus Concealment.

It is my wish, someday, to see the rules straighten out on the topics....

How about a perception saving throw?

Sort of like the concentration saving throw for spellcasters, a perception saving throw is a subset of a wisdom saving throw specifically for perception.

Saves are supposed to be for things done to you. Wizard firballs you, you make a dex save. Rogue tries.to hide from.you make a wis(perception) save to see them.

Now the question is do you make the save when the rogue hides, or do you wait and do it at the end of your turn? Or what?

I would probably start by cleaning up various terminology

Entity

For convenience, I will refer to creatures, objects, spell effects, terrain features, and other types of effects as entities, just meaning it's something potentially visible that has a location.

Unseen

An unseen entity is a entity that can not or has not been seen. An entity can be unseen by one observer and not by another. This means

• Attacks against an unseen entity are made with disadvantage.
• Attacks by an unseen entity are made with advantage.
• An ability that requires seeing its target does not work on an unseen entity.
• An unseen creature is potentially able to gain surprise.
• An entity is no longer unseen when it has been seen.

Unheard

An unheard entity is an entity that can not or has not been heard. 

• An entity that is unseen cannot have its location determined by hearing. It can still be determined in other ways, including sight.

Blind

A blind creature cannot see with with normal vision, darkvision, or truesight, potentially rendering other entities Unseen.

Concealment

Concealment is the visual equivalent of cover -- cover blocks line of effect, while concealment blocks line of sight. Most concealment affects normal vision, darkvision, and truesight, but not blindsight. An entity that has full cover cannot be seen with affected senses, potentially rendering it Unseen. A creature can have concealment from only some locations or angles.

Darkness

Entities in an area of darkness cannot be seen with normal vision, potentially rendering them Unseen.

Heavily Obscured

Entities in a heavily obscured area cannot be seen with normal vision, darkvision, or truesight, potentially rendering them Unseen. See also Opaque.

Hidden

A hidden entity is difficult to see, requiring a skill check with normal vision or darkvision. A creature can be hidden from only some locations or angles.

Invisible

An invisible creature cannot be seen with normal vision or darkvision, potentially rendering it Unseen.

Opaque

An opaque effect blocks normal vision, darkvision, and truesight into, out of, or through it. An entity inside an opaque effect is Blinded and Heavily Obscured; entities outside of the effect may gain Concealment.

Quote from Pantagruel666 >>

I would probably start by cleaning up various terminology

Entity

For convenience, I will refer to creatures, objects, spell effects, terrain features, and other types of effects as entities, just meaning it's something potentially visible that has a location.

Unseen

An unseen entity is a entity that can not or has not been seen. An entity can be unseen by one observer and not by another. This means

• Attacks against an unseen entity are made with disadvantage.
• Attacks by an unseen entity are made with advantage.
• An ability that requires seeing its target does not work on an unseen entity.
• An unseen creature is potentially able to gain surprise.
• An entity is no longer unseen when it has been seen.

Unheard

An unheard entity is an entity that can not or has not been heard. 

• An entity that is unseen cannot have its location determined by hearing. It can still be determined in other ways, including sight.

Blind

A blind creature cannot see with with normal vision, darkvision, or truesight, potentially rendering other entities Unseen.

Concealment

Concealment is the visual equivalent of cover -- cover blocks line of effect, while concealment blocks line of sight. Most concealment affects normal vision, darkvision, and truesight, but not blindsight. An entity that has full cover cannot be seen with affected senses, potentially rendering it Unseen. A creature can have concealment from only some locations or angles.

Darkness

Entities in an area of darkness cannot be seen with normal vision, potentially rendering them Unseen.

Heavily Obscured

Entities in a heavily obscured area cannot be seen with normal vision, darkvision, or truesight, potentially rendering them Unseen. See also Opaque.

Hidden

A hidden entity is difficult to see, requiring a skill check with normal vision or darkvision. A creature can be hidden from only some locations or angles.

Invisible

An invisible creature cannot be seen with normal vision or darkvision, potentially rendering it Unseen.

Opaque

An opaque effect blocks normal vision, darkvision, and truesight into, out of, or through it. An entity inside an opaque effect is Blinded and Heavily Obscured; entities outside of the effect may gain Concealment.

 

Ah, I like this. It's basically everything I was thinking. Specifically, I think the distinction between Concealment and Cover is incredibly important for the verisimilitude of the game. I was also going to get into darkness (lack of light) and opaque (blocking light) in a different post, but here we are :).

"cover blocks line of effect fire" <-- cover blocks attacks. Increase your AC or make you impossible to hit. Increase your Saving Throw. 

Cover blocks line of fire. Concealment blocks line of sight. 

You can be behind thick glass that gives you Cover even though you are not Concealed. You can paint yourself with mud and be Concealed even though you have no protective Cover. You can also be behind the ridge of a hill and have both Cover and Concealment.

"Heavily Obscured" is redundant to "Opaque" and Opaque is a better term and has a better definition. You might change Heavily Obscured definition to::   Heavily Obscured: Legacy. See Opaque.

I'd replace "unseen" with the condition called "concealed", just because "un" anything is awkward. This does mean you have the term "concealment" refering to things that conceal you, such as camoflage, and the term "Concealed" referring to a condition. 

Hidden : you have successfully taken the Hide action and are out of the enemy's sight (for ex, behind something opaque), therefore you have the Concealed condition

Invisible: enemy cannot see  you therefore you have the Concealed condition.

Concealed: The enemy cannot perceive your exact location. Attack rolls against you have disadvantage. You attack enemies with advantage. You cannot be targeted by a feature that requires you to be seen. 

"An entity that has full cover  (is fully concealed) cannot be seen with affected senses, potentially rendering it Unseen."

"A creature can may have concealment from only some locations or angles. " 

 Hide[Action]: you are behind 3/4 or better concealment between you and all enemies and make a Dexterity(Stealth) check, with a DC of 15 or the Passive Perception of any enemy that could potentially see you. On a success, you have the Hidden Condition. The value you roll for Dexterity(Stealth) becomes the DC for any Wisdom(Perception) check that any enemy takes to find you with their Wisdom(Percpetion) check or their Passive Perception.

Quote from SunIsGettingRealLow96589 >>

"cover blocks line of effect fire" <-- cover blocks attacks. Increase your AC or make you impossible to hit. Increase your Saving Throw. 

Total cover blocks line of effect, which includes but is not limited to attacks. See spell targets and cover.

Quote from Pantagruel666 >>

Quote from SunIsGettingRealLow96589 >>

"cover blocks line of effect fire" <-- cover blocks attacks. Increase your AC or make you impossible to hit. Increase your Saving Throw. 

Total cover blocks line of effect, which includes but is not limited to attacks. See spell targets and cover.

Cover is anything that protects you from damage, such as terrain, a stone wall, a large tree. Half Cover: +2 to AC and Dex saves. Theee-Quarter Cover: +5 to AC and Dex saves. Full cover: Cannot be hit by attacks, cannot be damaged by Dex Save effects unless the effect is described as being able to go around corners.

FYI: All of my comments on this thread are released under the Creative Commons Zero license.

https://wiki.creativecommons.org/wiki/CC0

Quote from SunIsGettingRealLow96589 >>

Cover is anything that protects you from damage, such as terrain, a stone wall, a large tree. Half Cover: +2 to AC and Dex saves. Theee-Quarter Cover: +5 to AC and Dex saves. Full cover: Cannot be hit by attacks, cannot be damaged by Dex Save effects unless the effect is described as being able to go around corners.

Full cover: can't be targeted. It doesn't just stop damage, it stops everything.

"Full cover: cant be targeted"

I would need a full definiton of what "targeting" means in dnd.

If i see a redwizard behind a transparent wall of force, i can "target" them in the military sense, i have determined their location.  But none of my attack rolls can hit them.

But if something lets me relay my targeting information to someone else, say my warlock friend who cannot see the red wizard from his angle, the warloc might be able to do an artillery strike on the red wizards position. 

Quote from SunIsGettingRealLow96589 >>

I would need a full definiton of what "targeting" means in dnd.

Targeting means picking a target for an attack, spell, or other ability. Acting as a forward observer for someone else is not targeting in the D&D sense.