When you reach 20th level, you gain mastery over two powerful spells and can cast them with little effort. Choose two 3rd-level wizard spells in your spellbook as your signature spells. You always have these spells prepared, they don't count against the number of spells you have prepared, and you can cast each of them once at 3rd level without expending a spell slot. When you do so, you can't do so again until you finish a short or long rest.
If you want to cast either spell at a higher level, you must expend a spell slot as normal.
At 18th level, you have achieved such mastery over certain spells that you can cast them at will. Choose a 1st-level wizard spell and a 2nd-level wizard spell that are in your spellbook. You can cast those spells at their lowest level without expending a spell slot when you have them prepared. If you want to cast either spell at a higher level, you must expend a spell slot as normal.
By spending 8 hours in study, you can exchange one or both of the spells you chose for different spells of the same levels.
Starting at 14th level, you can increase the power of your simpler spells. When you cast a wizard spell of 1st through 5th level that deals damage, you can deal maximum damage with that spell.
The first time you do so, you suffer no adverse effect. If you use this feature again before you finish a long rest, you take 2d12 necrotic damage for each level of the spell, immediately after you cast it. Each time you use this feature again before finishing a long rest, the necrotic damage per spell level increases by 1d12. This damage ignores resistance and immunity.
Beginning at 10th level, you can add your Intelligence modifier (minimum of +1) to one damage roll of any wizard evocation spell that you cast.
Starting at 6th level, your damaging cantrips affect even creatures that avoid the brunt of the effect. When a creature succeeds on a saving throw against your cantrip, the creature takes half the cantrip's damage (if any) but suffers no additional effect from the cantrip.
Beginning at 2nd level, you can create pockets of relative safety within the effects of your evocation spells. When you cast an evocation spell that affects other creatures that you can see, you can choose a number of them equal to 1 + the spell's level. The chosen creatures automatically succeed on their saving throws against the spell, and they take no damage if they would normally take half damage on a successful save.
Beginning when you select this school at 2nd level, the gold and time you must spend to copy a Evocation spell into your spellbook is halved.
At 3rd level, you have scribed a set of arcane formulas in your spellbook that you can use to formulate a cantrip in your mind. Whenever you finish a long rest and consult those formulas in your spellbook, you can replace one wizard cantrip you know with another cantrip from the wizard spell list.
This spell is cast as a reaction, which you take when a creature you can see within 60 feet of yourself succeeds on an attack roll, an ability check, or a saving throw
You magically distract the triggering creature and turn its momentary uncertainty into encouragement for another creature. The triggering creature must reroll the d20 and use the lower roll.
You can then choose a different creature you can see within range (you can choose yourself). The chosen creature has advantage on the next attack roll, ability check, or saving throw it makes within 1 minute. A creature can be empowered by only one use of this spell at a time.