dnd 5e – Blindsight and Tremorsense for a Blind PC?

Mechanically, within the radius of their blindsense, a blind character functions as a character with normal vision, with the benefit that nothing can obscure their vision.

Within that radius, this makes them stronger than creatures with darkvision standing in darkness. They are immune to the effects of spells like fog cloud and darkness (and of course, spells that cause blindness), and their opponents gain no benefit from effects that render themselves invisible.

Outside that radius, everything is heavily obscured and opponents have the benefit that they don’t need to use those spells or effects (conserving resources). The character has disadvantage on attack rolls against opponents at this range, while these opponents have advantage on attack rolls against the character.

By focusing on melee combat (unarmed strikes) the monk is able to take advantage of some of the above benefits simply by staying close to the enemy. Even deflect missiles, since it doesn’t depend on sight1, works as normal, mitigating some of their weakness against ranged attacks. In addition, the Way of Shadow monk will be able to cast darkness without hindering their own “sight”. Even the Way of the Four Elements monk is not significantly limited, as very few of their “spells” rely on sight.

All in all blindsight is a decent way to wave off the mechanical disadvantages of blindness, and a clever player can even take advantage of some of the above benefits. I would advise against including tremorsense though. If you look carefully you’ll see that is specific to burrowing monsters. Blindsight alone, even limited to 15 ft., is sufficient for this build.


1. As @SeriousBri points out, features that require sight will say “that you can see”; compare the Hunter Ranger’s uncanny dodge.

Blindsight vs Darkness and Shadows of Moil

Just curious how a dragon’s blindsight would interact with a PC casting darkness or shadows of moil.

Would the PC get advantage on their attack rolls, and would the dragon get disadvantage on it’s attack rolls?

Can a creature with Blindsight see a Scrying Sensor? Is that sensor an object? Can it be destroyed?

Scrying:

A creature that can see Invisible Objects sees the sensor as a luminous orb about the size of your fist.

Blind Sight:

A creature with blindsight can perceive its surroundings without relying on sight, within a specific radius. Creatures without eyes, such as oozes, and creatures with echolocation or heightened senses, such as bats and true dragons, have this sense.

dnd 5e – Does the Arcane Archer’s Shadow Arrow inhibit blindsight, tremorsense, and/or truesight?

Tremorsense and Blindsight are not “seeing”

Blindsight is pretty clear from the description:

without relying on sight.

Tremorsense is also not sight and only requires contact with the ground:

A monster with tremorsense can detect and pinpoint the origin of vibrations within a specific radius, provided that the monster and the source of the vibrations are in contact with the same ground or substance.

So the Arcane Archer’s Shadow Arrow would not affect blindsight and tremorsense at all.

Truesight

Truesight is still seeing, and seeing requires being able to see, so Shadow Arrow would prevent truesight from functioning outside of 5 feet. See this answer for details.

dnd 5e – Does a creature possessed by intellect devourer have blindsight?

The intellect devourer’s feature Body Thief says the following:

While inside a creature, the intellect devourer has total cover against attacks and other effects originating outside its host. The intellect devourer retains its Intelligence, Wisdom, and Charisma scores, as well as its understanding of Deep Speech, its telepathy, and its traits. It otherwise adopts the target’s statistics.

Does it retain its 60ft blindsight and immunity to the blinded condition while inside the creature?

dnd 5e – Can a creature with blindsight see another creature that is Heavily Obscured?

If a creature is Heavily Obscured, can it be seen normally by a creature with blindsight? More specifically, will a creature with blindsight have disadvantage on attacks against the heavily obscured creature?

For example, say that a creature is Heavily Obscured by the effects of Fog Cloud or Shadow of Moil, can that creature be seen by a creature with blindsight?

dnd 5e – Do crabs have blindsight out of water?

Yes, the crab has blindsight out of water

The statblock for the Crab adds no additional qualifiers to its senses, so the Crab has blindsight both in and out of water.

But it makes no sense for a normal crab to have blindsight out of water.

There are lots of things in DnD that make no sense. A mule can ride a phantom steed, for example. But it doesn’t ruin the experience, as the great thing about DnD is that you change the game to whatever makes for the most fun experience. If you want a crab familiar that’s blind out of water because it improves your immersion, then it’s absolutely your right, with DM approval, to modify the statblock accordingly.

In terms of balance

It shouldn’t be a concern. If you want to see this as an alternative way of casting See Invisibility, consider that a Crab can only see out to 30ft, while a PC casting See Invisibility can see out to their full range for the duration of the spell (1 hour, no concentration required). Additionally, it requires a full Action to switch to the familiar’s perspective, meaning that the combat utility of the Crab familiar’s blindsight is essentially null.

Additionally, a crab has a passive perception of 9, meaning that any reasonably stealthy invisible opponent will have no trouble defeating it with an average Dexterity (Stealth) roll, so its utility as a sentry is similarly poor.

dnd 5e – Does Blindsight detect a scrying sensor?

The description of the spell simply indicates that the sensor is invisible.
Invisible objects always have mass, physical dimensions and the like. If other properties were to be applied, terms like "intangible", "ethereal", etc. would have been used. It is therefore simply invisible according to the written rules.

The sensor is simply described as:

A creature that can see invisible objects sees the sensor as a bright orb the size of your fist.

According to this description, it does not emit any sound, smell or any other detectable evidence of its presence beyond being a bright ball if it can be seen.

Blindsight is described as:

A blind creature can perceive its environment without depending on sight, within a specific radius. Creatures without eyes, like oozing, and creatures with echolocation or high senses, like bats and real dragons, have this sense.

So it would seem that the type of blind vision is important. Eholocation would detect the presence of the sensor (as it has a physical manifestation) but, as formulated, heightened senses would not do so unless you decide that the sensor gives some form of clue. its presence which could be detected by Blindsight.

So what does Blindsight really mean for an Elder Oblex? Going through the Oblex statistics block, I would say no. He has no ability to suggest that he could detect a silent invisible ball, hovering

dnd 5e – How does Blindsight complement Truesight?

Although the definitions are fairly clear,

Blindness being:

A blind monster can perceive its environment without
based on the view, within a specific radius.

Eyeless creatures, such as grimlocks and gray seeps, usually
have this particular meaning, just like creatures with echolocation or
increased senses, like bats and real dragons.

If a monster is naturally blind, it has a note in parentheses
effect, indicating that the radius of his blind sight defines the
maximum range of perception.

and Truesight being:

A monster with real vision can, in a specific range, see in normal
and magical darkness, seeing invisible creatures and objects,
automatically detect visual illusions and successfully record throws
against them, and perceive the original form of a shapechanger or a
creature transformed by magic. In addition, the monster can
see in the ethereal plane in the same range.

It is easy to see that they each have their own unique apps. However, there seems to be a range of overlap between these senses with regard to visual illusions which raises many questions, mainly formulated as:

Does Blindsight allow a creature of ____________ as True?

For example.:

  • Does Blindsight allow a creature to see in normal, magical darkness?
  • Does Blindsight allow a creature to see invisible creatures and objects?
  • Does Blindsight allow a creature to automatically detect visual illusions and successfully save throws against it?

I apologize if this is a duplicate question, as I am sure it has already been asked, but as I did not find it in research, I thought it would be interesting to see the comparison between these two types of meaning, focusing on what is similar between them.

dnd 5th – can Blindsight see through the walls?

It depends.

Assuming you are talking about 5th-end:

A blind creature can perceive its environment without relying on sight, within a specific radius. Eyeless creatures, such as seeps, and creatures with echolocation or high meaning, such as bats and real dragons, have this meaning.

The rule does not say what blocks the blind view in general, but I regulate it according to the type of meaning. Sensations based on vibrations, such as seepage, may be able to detect through walls and floors, while bats probably can not detect behind solid walls. Blind vision based on perfume may depend on the type of obstruction, the walls being more blocking than shrubs.

It's up to the DM to decide the creature and the environment.