As an action, you create the image of an object, a creature, or some other visible phenomenon that is no larger than a sphere. The image appears at a spot within 20 meters and lasts for the duration. The image is purely visual; it isn’t accompanied by sound, smell, or other sensory effects.
As long as you are within 20 meters of the illusion, you can use an action to cause the image to move up to 5 meters to a space you can see, but the illusion must remain within 20 meters of you. As the image changes location, you can alter its appearance so that its movements appear natural for the image. For example, if you create an image of a creature and move it, you can alter the image so that it appears to be walking.
For the duration, you can cast spells as though you were in the illusion’s space, but you must use your own senses.
Physical interaction with the image reveals it to be an illusion, because things can pass through it. A creature can use an action to examine the image, making an ability check using Insight (Intelligence) against your spell save Difficulty. If it succeeds, it becomes aware that it is an illusion. If a creature discerns the illusion for what it is, the creature can see through the image, and any other sensory qualities of the image become faint to the creature.
Major Image. You can expend 1 additional mana so the image 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 concussion damage or deafen a creature, or a smell that might sicken a creature (like a troglodyte’s stench). Additionally, when you move the illusion you can cause it to make different sounds at different times, even making it carry on a conversation, for example.
Indefinite. You can expend 1 additional mana so the spell lasts until dispelled, without requiring your concentration.
Programmed Image. You can expend 2 additional mana so the illusion activates when a specific condition occurs. The illusion is imperceptible until then. It must be no larger than a 5-meter cube, and you decide when you cast the spell how the illusion behaves and what sounds it makes. This scripted performance can last up to 5 minutes.
When the condition you specify occurs, the illusion springs into existence and performs in the manner you described. Once the illusion finishes performing, it disappears and remains dormant for 10 minutes. After this time, the illusion can be activated again.
The triggering condition can be as general or as detailed as you like, though it must be based on visual or audible conditions that occur within 5 meters of the area. For example, you could create an illusion of yourself to appear and warn off others who attempt to open a trapped door, or you could set the illusion to trigger only when a creature says the correct word or phrase.