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.

  • \$\begingroup\$ "What do you allow" is a survey question not well suited to this site. You may want to try a forum \$\endgroup\$ Commented May 31, 2020 at 17:35
  • \$\begingroup\$ @Pleasestopbeingevil Would it be more appropriate to ask what the right way to decide is? My thought was that different methods have trade-offs and so might be more appropriate for some players than for others, but the downvotes on the current answers seem to suggest that some methods are just incorrect. \$\endgroup\$
    – Bagley
    Commented May 31, 2020 at 17:53
  • \$\begingroup\$ I think there's a really good, useful question in here somewhere, but, based on the answers it has attracted so far it clearly needs a bit of work first. Since you're asking from the perspective of a gm, you may want to focus it as a [gm-techniques] question, so it can be answered with supported expertise. I totally get that this is difficult (I'm not sure how you'd do it myself for this specifically), so you might want to open a question workshop on Role-playing Games Meta to hammer it out in more depth. \$\endgroup\$
    – Someone_Evil
    Commented May 31, 2020 at 18:17

1 Answer 1


I allow what the rules say

The designers have stated that there are no secret rules. Therefore, the methods stated in the spell are the only methods of penetrating the illusion. And yes, that applies to the person casting the spell - knowing that a spell is an illusion, does not prevent it from affecting you; unless and until you “discern” it as the spell allows.

Illusion spells are not tricks of light - they are powerful magic effects. They can make you believe things you know aren’t true.

  • \$\begingroup\$ While the question is locked I am curious to know why people disagree with this answer. \$\endgroup\$
    – SeriousBri
    Commented May 31, 2020 at 21:24
  • 1
    \$\begingroup\$ I didn't downvote, but this answer states things as facts without providing sources. And these things are a matter of discussions since quite a few editions. For example if Disguise Self is not a trick of light, why someone's hsnd cam pass thru? And for "discern" it basically means obtaining knowledge of reality, right? No rule or official clarification I've seen says one or the other way about caster needing to do this. \$\endgroup\$
    – Mołot
    Commented May 31, 2020 at 22:08
  • 1
    \$\begingroup\$ @SeriousBri I don't disagree with this answer and I think it's fine, but I downvoted because the question was very blatantly close-worthy and I approve of downvoting (+deleting) answers to questions that are extremely close-worthy, in order to discourage willful ignorance as to their closeability. If the question is reopened and this answer is still good I will reverse my vote. \$\endgroup\$ Commented Jun 1, 2020 at 4:14

Not the answer you're looking for? Browse other questions tagged .