You create an illusory copy of yourself that lasts for the duration. The copy can appear at any location within range that you have seen before, regardless of intervening obstacles. The illusion looks and sounds like you but is intangible. If the illusion takes any damage, it disappears, and the spell ends.
You can use your action to move this illusion up to twice your speed, and make it gesture, speak, and behave in whatever way you choose. It mimics your mannerisms perfectly.
You can see through its eyes and hear through its ears as if you were in its space. On your turn as a bonus action, you can switch from using its senses to using your own, or back again. While you are using its senses, you are blinded and deafened in regard to your own surroundings.
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 any noise it makes sounds hollow to the creature.
* - (a small replica of you made from materials worth at least 5 gp)
If it is intangible can it move through walls? If i can move it twice my movement can I move it directly into the air? So many things that an intangible illusion should be capable of completely left out of the spell. Can I move it to a place I cannot see?
Can it go through walls?
I don't understand why they made this spell so impossible to interpret when basically it is Mislead with longer range
This overlaps a lot with Mislead. The major difference is the range.
For deception/scouting in hectic moments, I'd for sure use Mislead over Project Image.
If you cast disguise self on yourself first is the projection also disguised?
also while I imagine a shapechanger could disguise what would someone with truesight see the casters true form or just that it was an illusion?
"you can choose one inanimate, nonmagical object that is part of the illusion and make that object real". That's a hard "no" on two different fronts.
As others have pointed out, the writing of this spell is very problematic. It is not at all clear how an intangible illusion could take damage. To me, it seems impossible for an intangible illusion to take any sort of damage - which makes the fourth sentence of this spell description unnecessary and confusing.
In defending this spell, others have mistakenly claimed that there are certain undead monsters, like ghosts, specters and shadows, that are also intangible but can take damage. They are wrong. As of this writing, there are no intangible creatures in official fifth edition D&D. Ghosts and specters have incorporeal movement, but they are not intangible. Shadows are amorphous, but still have a physical nature. These distinctions matter. RAW, you can successfully grapple a ghost, specter or shadow. Ghosts and specters could, of course, automatically get out of the grapple on their turn, but they would still have to wait for their turn. You cannot successfully grapple an illusion.
Others have mistakenly claimed that Mirror Image duplicates are destroyed when they take damage. That is also wrong. They are destroyed when they are hit. The damage of the attack that hits them is inconsequential and the spell description explicitly states that the duplicates ignore all other forms of damage.
Intangible means lacking a physical form. To me, that would seem to make it immune to bludgeoning, piercing, slashing, force, fire, cold, lightning, acid, poison, thunder, necrotic and radiant damage; magical or otherwise. And since an illusion has no mind, it would also appear to be immune to psychic damage.
Maybe my understanding is different from yours, but without any official explanation of what could damage an intangible illusion, we are left to argue amongst ourselves.