Can I have two castings of minor illusion active at the same time?

I had made a new half-elf sorcerer who will soon be a rogue multi-class. His spells are based off of what a rogue would choose them to be, such as fog cloud, mage hand, and minor illusion. In addition, I chose prestidigitation in the hopes of combining with minor illusion, using one for sound and one for an image.

Yet it was never clear to me if I could just use minor illusion twice, as it is a cantrip. This will free up a cantrip spot for a more offensive spell, seeing as all of my other spells are more ability than offense. We are playing D&D 5E.

Can I have two castings of minor illusion active at the same time?

Can minor illusion or prestidigitation create a spyglasss that works?

Can I create a lens that will function as a magnifying glass or spyglass with Minor Illusion Using the illusion as a focus to warp or bend light as a lens might.

Alternatively, can Prestidigitation Create a spyglass or magnifying glass?

You create a nonmagical trinket or an illusory image that can fit in your hand and that lasts until the end of your next turn.

Can Minor Illusion be used to replicate non-physical attacks?

Recently as a player my party fought against a creature that could paralyze you if you looked at it. Since my rogue has now seen it, would it be possible to replicate this using Minor Illusion by creating a image of the creature, and would it work the same way or be less effective? Could this also be used to replicate the attack the creature used that could kill if you failed the saving throw?

What Illusion spell would allow me to trick two enemies into fighting each other?

Is there a good spell or combination of spells that will allow me to cause opponents to see their allies as the enemies they are fighting? Either one on one or in groups? The intention is to make them fight their allies thinking that the allies are the enemy.

The best i can think of is using Major Image and placing it over another creature, so that his companions see him as the bad guy. Then through concentration I can manipulate the illusion to make it look like its fighting… Unfortunately that would only work for one attack because once the illusion is touched the opponent can see through it… Any other options?

Does the illusion described in the spell mental prison extend to the space above the target creature?

The spell text reads:

you make the area immediately around the target’s space appear dangerous in some way. (XGtE, pg. 161)

And the spell’s 10d10 damage triggers when,

the target is moved out of the illusion…or reaches any part of its body through it.

It seems this can be interpreted to mean the illusion appears on all sides around the target and not necessarily above the target. Can a creature with immunity to restrained and a flying speed avoid the 10d10 damage by flying up and out of the illusion?

How can Illusion Magic be effective against True Sight?

I am starting a new campaign and decided to play a wizard this time around. I was looking through the different schools available and reading guides (Treantmonk’s among others) and saw illusion as one of the most liked ones. However, my DM and one of the other players have tried to dissuade me from this choice as a lot of higher level creatures (our last campaign went from 1 – 20) have true sight thereby making the illusions worthless.

My question is: How can an illusion wizard still be effective against creatures with true sight for a campaign that will extend to level 20?

Can I Minor Illusion a 5ft box around myself to write notes when I know I am being scryed on?

My party is being scryed on by an enemy. We are all low level and don’t have access to second level spells yet. Can I get out paper and quill, cast minor illusion around myself as a 5ft cube of hollow stone, and write down sensitive information. Then pass the folded up paper to a party member and cast the illusion around them so they can read it? My theory is that because the scrying sensor is always 10ft away from the target they would just see a block of stone.

From Scrying:

On a failed save, the spell creates an invisible sensor within 10 feet of the target. You can see and hear through the sensor as if you were there. The sensor moves with the target, remaining within 10 feet of it for the duration.

Can you (as a druid/trickery domain cleric) invoke duplicity, wild shape, and then cast spells through the illusion?

I am Dming a DnD 5e game. I have a player who is trying this out. My thoughts are wild shape says you can’t cast spells, and tricky domain says you cast spells as though you were in their space. So RAW it seems you can’t. Their argument was…

I was thinking you can’t cast spells because you don’t have hands or a way to do the verbal components, but since you control the duplicate at will, then you should be able to have IT do the Verbal/Somatic stuff.

Thoughts? I’m pretty sure RAW its not allowed, do you think it would create an unbalance to allow it?

As a GM, how do you decide when a creature has discerned an illusion for what it is?

Many illusion spells, such as minor illusion and silent image have a clause that reads:

If a creature discerns the illusion for what it is, the illusion becomes faint to the creature.

The illusions often have a method or two in the spell description explaining how a creature can determine there’s an illusion, but I’m wondering what other methods, if any, would allow a creature to discern an illusion.

This answer states (and I concur) that there’s nothing in the text that would indicate that the methods given are the only methods to discern the illusion and many people seem to agree that illusionists are not subject to their own illusions, even though that isn’t explicitly mentioned in the spell description; another potential method for discerning illusions is by being told by a trusted ally that the object/creature is an illusion, although I don’t see people talk about that as much. Thus, it seems likely there are more potential methods people may be familiar with as well.

What methods do you allow characters to use to discern illusions outside of those that are mentioned in the spell description, why, and how do you effectively communicate your decision on the issue to players? I suspect there has to be a consideration of game balance, ease of adjudication, and believability, among other things, so I’m hoping to hear about how decisions actually play out when used at the table.