After careful thought, I would have to say that Blindsight is linear like regular sight, allowing detection of anything not physically obscured.
So something behind a door would block both vision and Blindsight.
Something behind a window would block Blindsight but allow vision.
An visual illusion that you cannot touch would block vision but not Blindsight.
Invisibility is tricky. If it blocks heat (possible form of Blindsight) then it would cause overheating problems (though that seems too nuanced for 5e). We know it does not block sound, so at least some Blindsight should be able to ignore it.
So, to summarize:
Physical objects (walls, glass, creatures, trees) should block Blindsight.
Visual illusions should not block Blindsight. (Just Blindsight would ignore the illusion entirely)
Invisibility should block Blindsight not based on sound/hearing.
As to Truesight, it seems that there is some overlap in function, but with Truesight appearing all-around better. I would consider the overlap an oversight, one hard to avoid in a "rules light" system.
And utilizing blindsight mechanically fills the role of a visual sense, and nothing more. Consider the Gray Ooze: it has blindsight, is entirely blinded beyond blindsight range (60ft), has no heightened senses, and does not indicate its blindsight as being tied to any other type of sense. It is quite literally just "vision" without eyes, so I fully expect invisibility to have an interaction with "vision".
For what it's worth, I take "An invisible creature is impossible to see without the aid of magic or a special sense" to mean "an invisible creature is possible to see with the aid of magic or a special sense", not "an invisible creature is automatically seen/located with the aid of magic or a special sense". Blindsightis a form of sight, regardless of narrative description. It is not auto-detection.
It's equivalent to 'sight that is unaffected by mechanics that are specific to vision'. As invisible is a vision-specific mechanic, you simply ignore it when considering blindsight. That doesn't mean automatic detection, it's possible to fail to detect visible objects, but that's generally because they have cover.
Agree to disagree. I say it's equivalent to "sight that is specifically vision, unaffected by however you decide to explain having it" 🤷♂️ Better than Darkvision, and not as good as Truesight
It's different, not better or worse. Various differences from truesight
Cannot see through illusions unless those illusions are visual only.
Cannot see the true form of shapeshifters.
Cannot see ethereal creatures.
Cannot see purely visual artifacts (this probably means cannot read unless the script has non-visual effects)
Can penetrate vision blocking spells like Fog Cloud.
I think that, after reading all the responses and considering how vaguely it's worded (it seems vague enough that they assumed it was an obvious answer), I'm inclined to treat it like regular sight, but it's not affected by darkness or the blinded condition. doors, walls, obstacles etc. are still going to obscure things from blindsight.
The iffy case is fog or smoke. I feel that, because smoke/fog is a physical thing to see, a creature with blindsight would see it and so it can obscure the vision. Basically, it's a higher tier of darkvision (works in magical darkness) with the added bonus of being immune to blinded conditions. I think that the word "sight" means it should be treated as sight in all respects, except that it has limited range and is immune to these things.
Overall, WOTC did great trying to simplify, didn't they?
Sometimes, you throw out important things when you try to simplify. Systems that do a better job would actually specify what sense they are using for targeting.
TCE gives us a much more concrete definition of blindsight by way of the blind fighting style
You have blindsight with a range of 10 feet. Within that range, you can effectively see anything that isn’t behind total cover, even if you’re blinded or in darkness. Moreover, you can see an invisible creature within that range, unless the creature successfully hides from you.
The problem is that we can't tell for certain if the following sentences are:
a definition of blindsight
additional rules to apply on top of the mysterious general blindsight rules
a mix of both
Personally I think this sort of thing is the result of WotC trying to keep the list of special senses short and sweet, and sometimes you need to infer the nature of the particular creature's blindsight to make a ruling that makes sense. In general, it probably should not be able to penetrate total cover unless there is a compelling reason (i.e. a creature that uses blindsight explained as exceptional hearing). In my own creatures, I use tremorsense exclusively for that kind of thing.
It works fine as a definition of blindsight. I know in this channel we like to look for opportunities to inject ambiguity into answers, but it really is not necessary in this case. Nothing in the feature description for blind fighting contradicts anything in the existing older blindsight description--it only serves to clarify and remove ambiguity, which I assume was the purpose of this thread in the first place.
The problem is that we can't tell for certain if the following sentences are:
a definition of blindsight
additional rules to apply on top of the mysterious general blindsight rules
a mix of both
If the blindsight granted by blind fighting is non-standard, I would expect verbiage such as "In addition, within that range...". There's also the fact that this is identical to the way it worked in 3.5e:
Some creatures have blindsight, the extraordinary ability to use a nonvisual sense (or a combination of such senses) to operate effectively without vision. Such sense may include sensitivity to vibrations, acute scent, keen hearing, or echolocation. This ability makes invisibility and concealment (even magical darkness) irrelevant to the creature (though it still can’t see ethereal creatures and must have line of effect to a creature or object to discern that creature or object). This ability operates out to a range specified in the creature description.
and the way it worked in 4e
Blindsight: A creature that has blindsight can clearly see creatures or objects within a specified range and within line of effect, even if they are invisible or in obscured squares.
And then there are those who consider that because blindsight can cover many different abilities and it would be annoying to have detailed rules about each ("If the rules tried to do so, the game would become unplayable."), they would do exactly what was in their design intent and recognise that, depending on the creature, the blindsight would work as needed by the DM.
"We aren't going to tell you how this monster actually works, make it up for yourself" is terrible game design. If you want your monster's blindsight to see through walls, just indicate in its stat block that it can do so.
No. The questions asked in this thread (can it see through walls? Can it see invisible? Can it see through darkness?) should be answered in the core description of the ability, and monsters with blindsight should have some sort of descriptive text so DMs have some idea of what their blindsight is and can make an informed decision about unusual interactions.
And why should it be, if there are breeds of that ability which vary depending on the creature ? I want my monsters to be different and potentially surprise players, and I think that it's normal that echolocation works differently from heightened senses and other special mystical senses. Once more, it has never been the intent of 5e to provide an answer for every type of use case. The rules do exactly what you asked the first time, but now you are moving goalposts.
Because the point of rules is to save work for the DM, and leaving those things obscure just wastes time trying to figure out what they mean. There's no need to answer every use case, but it should most certainly explain the basic function of abilities, and there's nothing preventing you from saying Blindsight (Echolocation) has special effects in your game whatever the basic rules specify (though aside from 'blind in silence fields', which the description of creatures with echolocation already specifies, other distinctions are mostly below the granularity of the rules).
"We aren't going to tell you how this monster actually works, make it up for yourself" is terrible game design.
The fact of the matter is that if this is how you feel, then there are a great many role-playing games that are simply not for you. Placing rules agency in the hands of the storyteller is a feature of game design, not a bug.
"We aren't going to tell you how this monster actually works, make it up for yourself" is terrible game design.
The fact of the matter is that if this is how you feel, then there are a great many role-playing games that are simply not for you. Placing rules agency in the hands of the storyteller is a feature of game design, not a bug.
I have no objection to placing rules agency in the hands of the DM, but you don't do that by providing half-rules. You do that by providing descriptive text with no attached rules at all, or rules with explicit gaps. Where rules exist, they should be clear and not require undue effort to figure out what they are intended to mean.
Six years on for 5e and this subforum in particular is full of people who strike me as much more comfortable with the structure-heavy crunchiness of earlier editions of Dungeons and Dragons than the streamlined "rules light" version we have in front of us today where brevity and conciseness takes precedence over wording that covers every situational possibility.
And that is in no way intended as an insult because I do not see earlier versions as inferior--just different.
Six years on for 5e and this subforum in particular is full of people who strike me as much more comfortable with the structure-heavy crunchiness of earlier editions of Dungeons and Dragons than the streamlined "rules light" version we have in front of us today where brevity and conciseness takes precedence over wording that covers every situational possibility.
"I can't figure out what this rule even means" is not rules-light. It's just bad. The essence of being rules light is having few rules, not having opaque rules.
Please explain what is opaque in these rather short paragraphs, honestly:
The fact that this thread exists. Adding about a sentence would be plenty. e.g.
A monster with blindsight can perceive its surroundings without relying on sight, within a specific radius. Within that radius it is immune to visual effects, such as blindness, darkness, illusions, and invisibility, unless that effect would also deceive or block the sense it is using. It is generally still blocked by total cover, though the DM may rule otherwise in specific cases.
Creatures without eyes, such as grimlocks and gray oozes, typically have this special sense, as do creatures with echolocation or heightened senses, such as bats and true dragons.
If a monster is naturally blind, it has a parenthetical note to this effect, indicating that the radius of its blindsight defines the maximum range of its perception.
After careful thought, I would have to say that Blindsight is linear like regular sight, allowing detection of anything not physically obscured.
So something behind a door would block both vision and Blindsight.
Something behind a window would block Blindsight but allow vision.
An visual illusion that you cannot touch would block vision but not Blindsight.
Invisibility is tricky. If it blocks heat (possible form of Blindsight) then it would cause overheating problems (though that seems too nuanced for 5e). We know it does not block sound, so at least some Blindsight should be able to ignore it.
So, to summarize:
Physical objects (walls, glass, creatures, trees) should block Blindsight.
Visual illusions should not block Blindsight. (Just Blindsight would ignore the illusion entirely)
Invisibility should block Blindsight not based on sound/hearing.
As to Truesight, it seems that there is some overlap in function, but with Truesight appearing all-around better. I would consider the overlap an oversight, one hard to avoid in a "rules light" system.
It's different, not better or worse. Various differences from truesight
Both penetrate normal darkness, magical darkness, and invisibility.
I think that, after reading all the responses and considering how vaguely it's worded (it seems vague enough that they assumed it was an obvious answer), I'm inclined to treat it like regular sight, but it's not affected by darkness or the blinded condition. doors, walls, obstacles etc. are still going to obscure things from blindsight.
The iffy case is fog or smoke. I feel that, because smoke/fog is a physical thing to see, a creature with blindsight would see it and so it can obscure the vision. Basically, it's a higher tier of darkvision (works in magical darkness) with the added bonus of being immune to blinded conditions. I think that the word "sight" means it should be treated as sight in all respects, except that it has limited range and is immune to these things.
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Fog/smoke I would say to be variable:
The creature should know if it is within such area due to feeling it.
Heavy smoke/fog should be blinding to heat/touch Blindsight (as well as impacting health for breathing races).
Heavy fog should be automatic detection of otherwise unobstructed things for sound Blindsight.
Heavy smoke & sound Blindsight is tricky. My gut says same as heavy fog, but there is nagging doubt.
Moderate fog would grant Advantage to sound I think, but Disadvantage to heat/touch.
Moderate smoke would grant Disadvantage to heat/touch, maybe Advantage to sound (see gut vs doubt ^)
Light smoke/fog I would say no change to sound, some penalty to heat/touch, but Disadvantage seems too harsh.
Overall, WOTC did great trying to simplify, didn't they?
Sometimes, you throw out important things when you try to simplify. Systems that do a better job would actually specify what sense they are using for targeting.
TCE gives us a much more concrete definition of blindsight by way of the blind fighting style
"Not all those who wander are lost"
The problem is that we can't tell for certain if the following sentences are:
Personally I think this sort of thing is the result of WotC trying to keep the list of special senses short and sweet, and sometimes you need to infer the nature of the particular creature's blindsight to make a ruling that makes sense. In general, it probably should not be able to penetrate total cover unless there is a compelling reason (i.e. a creature that uses blindsight explained as exceptional hearing). In my own creatures, I use tremorsense exclusively for that kind of thing.
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(Artificer) Swordmage | Glasswright | (Barbarian) Path of the Savage Embrace
(Bard) College of Dance | (Fighter) Warlord | Cannoneer
(Monk) Way of the Elements | (Ranger) Blade Dancer
(Rogue) DaggerMaster | Inquisitor | (Sorcerer) Riftwalker | Spellfist
(Warlock) The Swarm
It works fine as a definition of blindsight. I know in this channel we like to look for opportunities to inject ambiguity into answers, but it really is not necessary in this case. Nothing in the feature description for blind fighting contradicts anything in the existing older blindsight description--it only serves to clarify and remove ambiguity, which I assume was the purpose of this thread in the first place.
"Not all those who wander are lost"
If the blindsight granted by blind fighting is non-standard, I would expect verbiage such as "In addition, within that range...". There's also the fact that this is identical to the way it worked in 3.5e:
and the way it worked in 4e
Massive WOTC facepalm.
That 3.5e description could have been copy-pasted into 5e and (nearly) avoided any issues.
There was a fair amount of throwing out the baby with the bathwater in 5e.
"We aren't going to tell you how this monster actually works, make it up for yourself" is terrible game design. If you want your monster's blindsight to see through walls, just indicate in its stat block that it can do so.
Well, at the very least we know it’s not X-Ray vision, since that’s now a feature in the game that’s been described.
the ghost dragon thing in candle keep has blindsight as well as an additional feature called x-Ray vision.
No. The questions asked in this thread (can it see through walls? Can it see invisible? Can it see through darkness?) should be answered in the core description of the ability, and monsters with blindsight should have some sort of descriptive text so DMs have some idea of what their blindsight is and can make an informed decision about unusual interactions.
Because the point of rules is to save work for the DM, and leaving those things obscure just wastes time trying to figure out what they mean. There's no need to answer every use case, but it should most certainly explain the basic function of abilities, and there's nothing preventing you from saying Blindsight (Echolocation) has special effects in your game whatever the basic rules specify (though aside from 'blind in silence fields', which the description of creatures with echolocation already specifies, other distinctions are mostly below the granularity of the rules).
The fact of the matter is that if this is how you feel, then there are a great many role-playing games that are simply not for you. Placing rules agency in the hands of the storyteller is a feature of game design, not a bug.
"Not all those who wander are lost"
I have no objection to placing rules agency in the hands of the DM, but you don't do that by providing half-rules. You do that by providing descriptive text with no attached rules at all, or rules with explicit gaps. Where rules exist, they should be clear and not require undue effort to figure out what they are intended to mean.
Six years on for 5e and this subforum in particular is full of people who strike me as much more comfortable with the structure-heavy crunchiness of earlier editions of Dungeons and Dragons than the streamlined "rules light" version we have in front of us today where brevity and conciseness takes precedence over wording that covers every situational possibility.
And that is in no way intended as an insult because I do not see earlier versions as inferior--just different.
"Not all those who wander are lost"
"I can't figure out what this rule even means" is not rules-light. It's just bad. The essence of being rules light is having few rules, not having opaque rules.
The fact that this thread exists. Adding about a sentence would be plenty. e.g.