Abjuration Wizard
Abjuration Savant
Starting at 2nd level when you take this subclass, you can add 1 abjuration spell to your spellbook for free. Whenever you gain a level in this class, you may add another abjuration spell to your spellbook for free.
Additionally, the time and gold it takes you to copy abjuration spells into your spellbook is halved.
Arcane Ward
Starting at 2nd level, you can weave magic around yourself for protection. When you cast an abjuration spell with a spell slot, you can simultaneously use a strand of the spells magic to create a magical ward on yourself that lasts until you finish a long rest. The ward has a hit point maximum equal to twice your wizard level plus your intelligence modifier. Whenever you would take damage, the ward takes the damage instead. If the ward is reduced to 0 hit points, you take any remaining damage. While the ward has 0 hit points, it can't absorb any damage, but it's magic remains.
Additionally, when a creature that you can see within 30 feet of you takes damage, you can use your reaction to cause your Arcane Ward to absorb that damage. If this damage reduces the ward to 0 hit points, either you or the warded creature takes any remaining damage, your choice.
Whenever you cast another abjuration spell with a spell slot, the ward regains hit points equal to twice the level of the spell slot, and if it's not an abjuration spell, it only regains hit points equal to the level of the spell slot that you expended. Alternatively, as a bonus action, you can expend a spell slot, and the ward regains hit points equal to twice the level of the spell slot spent. These spell slots you expend as a bonus action recharge on a short rest.
You cannot create the ward again while it is already up, including when it is up with 0 hit points.
Improved Abjuration
Beginning at 6th level, you always have the spells Dispel Magic and Counterspell prepared. You may add your proficiency bonus to the ability check used in these spells.
Additionally, whenever your ward absorbs damage, you can choose to make the attacking creature suffer force damage equal to your proficiency bonus.
Spell Resistance
Starting at 10th level, you have advantage on saving throws against spells when your ward is up. Additionally, you and your ward have resistance against the damage of spells and magical effects.
Ward Nullification
At 14th level, your ward can absorb one massive blow entirely. Once per long rest, when your ward takes damage that would make it fall to 0 hit points, you can use your reaction to instead have the ward drop to 1 hit point, nullifying any remaining damage that would have gone to you.