D&D 5E Reminders on Illusions

[Swarmkeeper]

Which read literally means I can't create a minor illusion of a glowing sword mounted on a wall, which seems a bit (as in, a lot!) over-restrictive.

I-as-caster also can't have the illusion react properly to light sources e.g. reflections off the shiny blade of a non-glowing illusory sword.

In 5e, that's just how minor illusion works. It's a cantrip which can be cast at-will with the use of an action. If you want a glowing illusory sword without altering mechanics of minor illusion, there are leveled spells for that. Or you might come up with some other creative solution that would layer on a shimmering effect.

 

[BookTenTiger]

My DM and I came to this agreement about the use of illusions:

They are always believable, but not always effective.

So if I create the illusion of a fire blocking a door, it's believable. But an enemy might still fire through it, revealing it to be an illusion. Or they might be thrown off by the lack of heat, and take an action to make an Investigation check. Or just jump through the fire, accepting they might get a little burned, revealing it to be an illusion.

I'm glad there's not an absolute list of codified rules for illusions, because it's a lot more fun to have the creativity built into the flexibility.

 

[Dausuul]

In 5e, that's just how minor illusion works. It's a cantrip which can be cast at-will with the use of an action. If you want a glowing illusory sword without altering mechanics of minor illusion, there are leveled spells for that. Or you might come up with some other creative solution that would layer on a shimmering effect.

The inability to create light is part of how the spell works. Still waiting for a source on the reflection thing. (And, again, "Jeremy Crawford said so once" is not an authoritative rules source. When Crawford's utterances are released as official errata, then they become authoritative--not before.)

 

[ECMO3]

I've seen quite a few comments here, and in other places, where incorrect statements about illusions spells are stated. Here are a few reminders on our most common illusion spells. I am treating Sage Advice as RAW, as well as the interview from 12/27/2017 by Jeremy Crawford as RAW). Note that many DMs will overrule some of these rules - so if you plan to use illusions, I recommend discussing them with the DM in advance.

Minor Illusion

• Similarly, it can't create a shadow (note that a shadow is not part of the image of the thing created).

It can as long as it is all within the 5 foot cube and static, but it can't extend outside the 5 foot cube.

 

[Helldritch]

Illusions were much more powerful in previous editions and much more useful.

I do not know why 5ed went this way as illusions already had the problem of being disbelieved in the first place. Much restrictions for no true gains...

 

[DEFCON 1]

I imagine that the illusion of a sword or mirror or any reflective surface could have a "reflection" image upon it.... but that image wouldn't change. It would essentially be a painting upon the illusory image's surface, and wouldn't actually interact or reflect what was happening in front of it.

 

[BookTenTiger]

The inability to create light is part of how the spell works. Still waiting for a source on the reflection thing. (And, again, "Jeremy Crawford said so once" is not an authoritative rules source. When Crawford's utterances are released as official errata, then they become authoritative--not before.)

I'm not sure we really need sources on every thing an illusion can or cannot due.

If a sword being nonreflective, the candle producing a flame but no light... These are the things that can prompt an NPC to spend an action to make an Investigation check.

 

[ECMO3]

The inability to create light is part of how the spell works. Still waiting for a source on the reflection thing. (And, again, "Jeremy Crawford said so once" is not an authoritative rules source. When Crawford's utterances are released as official errata, then they become authoritative--not before.)

The problem with the discussion on light is the illusion has to alter light in its area of effect. Light is what your eyes sense so saying it can't create light means in effect it can't create an image. With this in mind I think the correct interpretation is the illusion alters the perception of light and it acts on the individuals mind to do this, not their eyes

The way I rule this for minor illusion and silent image is they cause or modify the perception of light specifically related to the illusion itself in their own area of effect.

For example you make an illusion of a 5 foot black box around a torch on the wall, then the box itself covers the wall, if you specify it is a completely dark and opaque 5 foot box then that 5 foot area is dark and looks like a black inky 5 foot cube. The area right outside the box is still in bright light from the torch, although anyone looking at it would not understand where the light is coming from. If you touch the box it turns "dim" and you see through it to the torch underneath and can see anything else in that 5 foot area as if it is in bright light.

Another example - If you are in completely dark area and create an image of a lit torch, everyone sees the torch, but the torch casts no light at all. Even if you create it right on top of a creature and know it is an illusion, you still can't see any part of that creature without darkvision or some comparable ability. In this respect it does not cast "light" even in the space it occupies but you would still "see" the torch itself. If you instead made a 5' bright sphere (i.e. a miniature sun), again everyone would see the sun but it would cast no light outside its space and anyone who recognized it for an illusion could "see" through it but would not see anything inside it without darkvision because there is no light there.

 

[MarkB]

I imagine that the illusion of a sword or mirror or any reflective surface could have a "reflection" image upon it.... but that image wouldn't change. It would essentially be a painting upon the illusory image's surface, and wouldn't actually interact or reflect what was happening in front of it.

The way I'd rule it is that it reflects the current lighting conditions, but not a live image of the surroundings - only the surroundings as they appeared to the caster when it was cast. So a silent image of a mirror cast within a room would reflect the static contents of the room, but not anyone who wasn't there when it was cast.

Likewise, if you cast it at an intersection ahead if you, you couldn't use it to scout by having it reflect the view from around the corner, because it can only show information the caster was aware of at the time of casting.

 

[BookTenTiger]

D-d-d-double post.