# If an arrow passes through an illusionary wall of fire created by the Major Image spell, does it reveal it as an illusion?

The Major Image spell description says:

You create the image of an object, a creature, or some other visible phenomenon that is no larger than a 20-foot cube. The image appears at a spot that you can see within range and lasts for the duration. It seems completely real, including sounds, smells, and temperature appropriate to the thing depicted. You can’t create sufficient heat or cold to cause damage, a sound loud enough to deal thunder damage or deafen a creature, or a smell that might sicken a creature (like a troglodyte’s stench).

[...]

Physical interaction with the image reveals it to be an illusion, because things can pass through it. A creature that uses its action to examine the image can determine that it is an illusion with a successful Intelligence (Investigation) check against your spell save DC. If a creature discerns the illusion for what it is, the creature can see through the image, and its other sensory qualities become faint to the creature.

One of my players wants to cast this as a Wall of Fire. He asked me what would happen if an enemy shoots through it.

As noted in the bolded sentence, physical interaction with the image reveals it to be an illusion.

Arrows have no problem with getting through a normal Wall of Fire. Would this reveal the illusion?

• Welcome to RPG.SE! Take the tour if you haven't already, and check out the help center for more guidance. – V2Blast Nov 30 '19 at 1:00
• – Medix2 Nov 30 '19 at 3:09

# Yes, the illusion is revealed

As quoted from the Major Image spell

Physical interaction with the image reveals it to be an illusion, because things can pass through it.

From what i could gather the confusion is in the because things can pass through it part. Since the arrow would normally pass through the fire if it was real anyway.

But that is actually incorrect.

Fire is displaced by objects that touch it. You can easily test this by placing a toothpick on top of a candle fire. The arrow would passthrough the fire without displacing it, revealing the illusion.

• I'm not sure I agree with phrasing like "fire is displaced by objects that touch it", or that holding a toothpick in a candle flame would show the same interaction as an arrow shooting through a wall of fire. But this answer is correct by RAW regardless, and the argument that the wall of flames would be affected in some visible way (if not necessarily very conspicuously) is definitely sound. – Upper_Case Dec 3 '19 at 19:35