Starting at 2nd level when you take this subclass, you can add 1 illusion spell to your spellbook for free. Whenever you gain a level in this class, you may add another illusion spell to your spellbook for free.
Additionally, the time and gold it takes you to copy illusion spells into your spellbook is halved.
When you choose this school at 2nd level, you learn the Minor Illusion cantrip. If you already know this cantrip, you learn a different wizard cantrip of your choice. The cantrip doesn't count against your number of cantrips known.
When you cast Minor Illusion, you can do so as a bonus action, and you can create both a sound and an image with a single casting of the spell.
Starting at 6th level, when you cast an illusion spell that has a duration of 1 minute or longer, you can use your bonus action to change the nature of that illusion (using the spell's normal parameters for the illusion), provided that you can see the illusion. You can also move silent image and major image as a bonus action instead of an action on your turns. Creatures have disadvantage to determine if your illusions are real or not.
Beginning at 10th level, you can create an illusory duplicate of yourself at an instant, almost instinctual reaction to danger. When a creature makes an attack roll against you, you can use your reaction to interpose the illusory duplicate between the attacker and yourself. The attack automatically misses you, then the illusion dissipates.
Once you use this feature, you must spend a spell slot of 2nd level or higher (no action required) to use it again until you take a short or long rest.
By 14th level, you have learned the secret of weaving shadow magic into your illusions to give them a semi-reality. When you cast an illusion spell of 1st level or higher, you can choose one inanimate, nonmagical object that is part of the illusion and make that object real. You can do this on your turn as a bonus action while the spell is ongoing. The object remains real for 1 minute. For example, you can create an illusion of a bridge over a chasm and then make it real long enough for your allies to cross.
The object can't deal damage or give any conditions.