Blindsight vs. Mirror Image (figment)

[tankschmidt]

I've looked through the old threads here and on the WoTC boards, but I couldn't for the life of me find the answer to this question:

If a monster has blindsight, is it affected by the Mirror Image spell or do figments not affect it? What if we're talking about the lifesense of a Dread Wraith instead? What about the lifesense feat in Libris Mortis (p.28)?

Are there any monsters that are immune to figments?

For your convenience:

Dread Wraith: http://www.d20srd.org/srd/monsters/wraith.htm
Blindsight: http://www.d20srd.org/srd/specialAbilities.htm#blindsightAndBlindsense
Figments and Glamers: http://www.d20srd.org/srd/magicOverview/spellDescriptions.htm#figment

Thank you in advance for your help!

 

[Hypersmurf]

If a monster has blindsight, is it affected by the Mirror Image spell or do figments not affect it?

It depends on two things - is the monster also blind, and does its blindsight rely on sound.

You cannot distinguish between the caster and the images by sight or hearing; thus, if the blindsight relies on sound, it will also be fooled.

However, if you cannot see the images, they have no effect; therefore, if the monster is blind, its blindsight will detect the caster and not the images whether or not the blindsight relies on sound.

If the blindsight relies on scent, or vibration, or something similar, it will not be fooled even if the monster can see, because it is not using sight or hearing to distinguish - this would also apply to the Dread Wraith's lifesense.

-Hyp.

 

[Caliban]

You cannot distinguish between the caster and the images by sight or hearing; thus, if the blindsight relies on sound, it will also be fooled.

However, if you cannot see the images, they have no effect; therefore, if the monster is blind, its blindsight will detect the caster and not the images whether or not the blindsight relies on sound.


-Hyp.

Hype, you crack me up.

In other words: "Blindsight based on sound doesn't actually function as blindsight if your eyes are open, but it works just fine if you close your eyes."

Apparently the images only make sounds if you can see them.

 

[Hypersmurf]

Apparently the images only make sounds if you can see them.

That's what the spell says - or rather, they may still make sounds, but you aren't fooled by them.

Similarly, if you're using the spell text (which would allow for images to potentially occupy a different square to the caster), you can't use a Listen check to determine which square the real caster is in as long as you can see the images. But if you can't see the images, a Listen check will work fine. (If you're using the FAQ's suggestion that it's simpler to put all the images in the same square as the caster, obviously using a Listen check to determine the square is unnecessary.)

"When you and the mirror image separate, observers can’t use vision or hearing to tell which one is you and which the image."

but

"An attacker must be able to see the images to be fooled. If you are invisible or an attacker shuts his or her eyes, the spell has no effect."

In other words: "Blindsight based on sound doesn't actually function as blindsight if your eyes are open, but it works just fine if you close your eyes."

It functions as blindsight, but the spell will trick the sound-based blindsight as well, unless you can't see the images.

-Hyp.

 

[tankschmidt]

Thank you both for your help!

For simplicity, let's go with the FAQ and assume all images are in the same square as the caster. So if I'm regular Joe Fighter, and I'm trying to attack a wizard who has four Mirror Images, I have two options.

1. I waltz up and attack the guy normally, with only a 20% chance of hitting him.

2. I locate the fella's square, waltz up as before, and close my eyes before swinging. Now I have a 50% chance of hitting him, right?

Meanwhile, creatures like Grimlocks are unaffected by the spell. And the craziest part is the case of a red dragon (with blindsense) shooting a ray spell at the wizard (within 60'). If he closes his eyes before firing off the spell, it has a better chance of hitting.

Is my interpretation correct then?

 

[Jack Simth]

Thank you both for your help!

For simplicity, let's go with the FAQ and assume all images are in the same square as the caster. So if I'm regular Joe Fighter, and I'm trying to attack a wizard who has four Mirror Images, I have two options.

1. I waltz up and attack the guy normally, with only a 20% chance of hitting him.

2. I locate the fella's square, waltz up as before, and close my eyes before swinging. Now I have a 50% chance of hitting him, right?

Meanwhile, creatures like Grimlocks are unaffected by the spell. And the craziest part is the case of a red dragon (with blindsense) shooting a ray spell at the wizard (within 60'). If he closes his eyes before firing off the spell, it has a better chance of hitting.

Is my interpretation correct then?

By the book, yes, nonsensical as it seems, although in Joe's case, if the Wizard has a readied action to move under such circumstances, you're hitting an empty square - 0% chance of hitting him.

 

[frankthedm]

Meanwhile, creatures like Grimlocks are unaffected by the spell. And the craziest part is the case of a red dragon (with blindsense) shooting a ray spell at the wizard (within 60'). If he closes his eyes before firing off the spell, it has a better chance of hitting.

Is my interpretation correct then?

Yes. Closing your eyes and using the Force is a legit tactic when your foe screws with your senses. Can't trust your eyes? Stop using them.

 

[Seeten]

my Sahuagin has Blindsense and Scent. Mirror Image users are SO doomed.

 

[Delta]

I am also cracked up.

 

[Zurai]

thus, if the blindsight relies on sound, it will also be fooled.

Not true. Blindsight-by-sound is echolocation or sonar - it relies on hearing, yes, but not on hearing the mirror image. Figments have no substance and thus echolocation and sonar do not detect them.

The "you cannot use hearing to distinguish between the images and the caster" bit is referring to the fact that the illusion includes auditory components, and thus makes all the same sounds the caster does. The sounds the images make are completely and totally irrelevant to blindsight.