D&D 5E Major Image (Spell): When should a creature use its action to examine something that it believes is real?

[bbrown12]

Hey guys,

the Major Image spell has no saving throw. Let's say a creature has no reason to arouse "natural suspicion" (like a guard patrol seeing a bush that hasn't been there before). So, creatures that see the image believe it to be real.

Furthermore, a creature has only two possibilities to find out, it's an illusion:

1. It physically interacts with the illusion (and sees things going through). This one is pretty simple and clear.
2. It takes its action to examine the illusion (therefore it makes an Investigation check against the Spellcasting DC).

My question is: When would a creature use its action to investigate something that it believes is real?

No one would ever come up with the idea to investigating a real creatures/characters/etc.

So, the only situation I can imagine is the following:

• Creature A finds out the image is an illusion, because of physical interaction (it has no reason to investigate) - maybe even by chance.
• Now, it shouts to his allied Creature B "Hey, this is an illusion!".
• Creature B has still no indications to take the image as an illusion, because it seems so real (sound, smell, temperature, etc.), except Creature A telling him for some strange reason.
• So, Creature B still needs to find out himself. He can always do so by physical interaction, but now it has well-founded indications that the image might be an illusion (because Creature A told him so).

So, the only way for a creature to take its action to investiagte the image is, if it has well-founded indication from outside (e.g. other creature).

Am I right?

TL;DR: I would never offer an NPC/Player the possibility to use its action to investigate an illusionary image, if it has no well-founded indication from outside (e.g. other creatures telling him). A creature believes the image is real, so why would it come up with the idea of investigating it? In addition, it always can find out it's an illusion by physically interacting with it (maybe by chance).

 

[Nailen]

Ok, so I'm a guard on patrol. On one patrol circuit I notice a bush, barrel, box has appeared that wasn't there before. I might decide to take a closer look...

Sent from my ONEPLUS A3000 using EN World mobile app

 

[bbrown12]

Ok, so I'm a guard on patrol. On one patrol circuit I notice a bush, barrel, box has appeared that wasn't there before. I might decide to take a closer look...

Yes, for sure, if there is a reasons for a creature to be suspicious, investigation is always possible.

To be honest, I concentrated on fighting situations or mimicing creatures/persons that don't arouse "natural" suspicion.

 

[Spookykid]

If its in a combat situation and a character shoots/swings at it thinking its real, it should automatically know its not.

 

[jaelis]

If you create an illusion that seems reasonable and realistic, I wouldn't have NPCs arbitrarily decide to investigate it. As a general rule, I would only call for the check if it is something they would be interested in investigating whether it is an illusion or not.

On the other hand, there are plenty of reasons to investigate something other than thinking it is an illusion (or even suspicious). If you create an illusion of a magnificent statue, probably most passers-by will investigate it and get a check.

 

[jgsugden]

Note that any physical interaction with the object reveals it to be an illusion. This does not mean that a creature has to interact with the illusion itself - it can just observe something or someone else interact with it. In theory, any physical interaction reveals it to be an illusion for all as there is no explicit requirement that the interaction be observed, but most people read that into the description or decide that the statement about a creature discerning the illusion means it must be observed.

As for using the action: Anytime the PC does not interact with the object, but spends an action involving the illusion, I give the Investigation check. They might be searching the area, doing an intelligence check to understand something about the illusion, etc....

 

[Dausuul]

If you live in a world where illusions are a thing, why would you not consider the possibility that they're being used against you?

Depending on how much the creature knows about illusions, cues could include something suddenly appearing out of nowhere; a combatant that seems weirdly reluctant to actually engage in combat; a combatant that is absolutely silent (suggesting a lower-level spell without an auditory component); a creature in an environment where it should not be, or where it could not plausibly get, such as a giant in a room with human-sized doors; etc.

No one would ever come up with the idea to investigating a real creatures/characters/etc.

Sure they would. I've seen it happen several times, done it myself. Using your action to investigate something for illusiveness (illusionism? illusority?) is a gamble. If the thing is an illusion, it pays off... but if the thing is real, you just wasted your action.

 

[jgsugden]

Note that if a PC has a passive investigation strong enough to find the illusion, I would always allow them to discern the illusion right off the bat...

 

[Irda Ranger]

It would be mentally exhausting to check everything you encounter for the possibility that it's an illusion. Especially when most things aren't illusions.

However in a world where illusions are real you can also grow a sense of caution. Sort of like I have done for phishing emails. I've developed (I think) a pretty good sense of what emails are suspicious and which are not, and I examine closely any email that arouses my concern.

As the DM I'd make a judgment call as to the NPC's likelihood of accepting the illusion is real, or investigating it further. And I'd also rule that most NPCs know that the easiest way to dispel an illusion is to interact with it physically, so they might toss a pebble at it or reach out with the tip of a staff or something else non-threatening to poke at stuff that's questionable.

So yeah, you can't just make an illusion of anything and expect NPCs to just buy it. But if you're smart and make illusions of things that people would find normal and un-suspicious, many of them will never be closely inspected.

 

[The Crimson Binome]

In general, you have cause to investigate something whenever you think that the chance of something being an illusion is significantly higher than the chance of it being real. Illusionists might be rare, but they do exist within the game world; maybe you ballpark a one-in-a-million chance that any given object of interest you see is an illusion. In that case, you should try to disbelieve anything you see that is substantially less likely than one-in-a-million. If you have reason to suspect that an illusionist is nearby, then that increases the base odds of something being an illusion, so it lowers the threshold of skepticism before deciding that something warrants investigation.

If you've ever played D&D back in the day, it became something of a habit for players to try and disbelieve anything that seemed too implausible. If you're wandering through a volcano and you encounter a snowman, then you know something weird is going on, so you will probably stop and investigate to find out whether it's an illusion or magical item or some sort of trap. If the only bridge across a moat to an enemy castle is suspiciously unguarded, then you know something weird is going on, so you will probably stop and investigate to find out whether it's an illusion or some sort of trap. Around these parts, that investigation usually comes in the form of shooting it to see whether it reacts or if the arrow simply passes through.

Depending on the player and their base level of skepticism - and what sorts of DMs they've been subject to in the past - they may opt to investigate everything. If you've ever seen a player stop and poke everything in the dungeon with a ten-foot pole before getting close to it, then that's probably a player who estimates a fairly significant chance that something isn't what it seems, even when they have no obvious reason to suspect that thing in particular; they wouldn't waste their own time if they didn't expect it to yield results.