Before wizards specialized by schools of magic, during more ancient times, the wizards of the world studied in a single tradition passed down by the very first wizards. This tradition, now called the School of the Ancients, is devoted to the study of the source and nature of magic itself. They memorize the true names that are magically woven into the fabric of the world, and learn to see the true nature of all things. As they delve deeper into their study and glimpse the source of the arcane, they begin to age more slowly than normal as their body adapts to the mysteries that have infused it.

Wizards of this ancient tradition organize in circles much like those of druids, but with more strict and even esoteric structures organizing their activity. Such circles usually keep their existence hidden and jealously guard the secrets they have unlocked from others — especially from other wizards — who aren't one of them.

Savant Studies

When you select this school at 2nd level, you choose either abjuration, conjuration, divination, enchantment, evocation, illusion, necromancy, or transmutation.

The gold and time you must spend to copy a spell of the chosen school into your spellbook is halved.

Chosen School: Abjuration

The gold and time you must spend to copy an abjuration spell into your spellbook is halved.

Chosen School: Conjuration

The gold and time you must spend to copy a conjuration spell into your spellbook is halved.

Chosen School: Divination

The gold and time you must spend to copy a divination spell into your spellbook is halved.

Chosen School: Enchantment

The gold and time you must spend to copy an enchantment spell into your spellbook is halved.

Chosen School: Evocation

The gold and time you must spend to copy an evocation spell into your spellbook is halved.

Chosen School: Illusion

The gold and time you must spend to copy an illusion spell into your spellbook is halved.

Chosen School: Necromancy

The gold and time you must spend to copy a necromancy spell into your spellbook is halved.

Chosen School: Transmutation

The gold and time you must spend to copy a transmutation spell into your spellbook is halved.

Ensorcelling Sight

Also at 2nd level, your sight becomes more open to the mysteries of the arcane, allowing you to see the true nature of others but revealing your wizardly nature to them in return as an overwhelming revelation.

As an action, you can peer into the true nature of one creature that you can see within 60 feet of you. You immediately learn the creature's maximum hit points, AC, type, and challenge rating (or level). You also learn the highest spell level that the creature is able to cast and any resistances, vulnerabilities, and immunities that it has. If the target can also see you, it must then make a Wisdom saving throw against your wizard spell save DC. On a failed saving throw, the target is incapacitated until the end of your next turn.

Once you use this feature, you can't use it again until you finish a short or long rest. 

Level 3

This Domain gains no features at level 3, but D&D Beyond requires an entry here.

Speak the Ancient Words

At 6th level, you study the ancient words and true names of the universe, allowing you to command power over magical creatures that you have studied.

You gain proficiency in Arcana. If you already have proficiency in Arcana, your proficiency bonus is doubled for any ability checks you make that use that proficiency.

Also, when a celestial, elemental, fey, fiend, or undead succeeds on a saving throw against one of your wizard spells, if you can speak, you can make an Intelligence (Arcana) check against a DC equal to 10 + the creature's challenge rating. On a success, you roll 1d4 and subtract the result from the creature's saving throw.

Once you make this Intelligence (Arcana) check, you can't do so again until you finish a short or long rest.

Arcana Expertise

If you have proficiency in Arcana already, your proficiency bonus is doubled for any ability checks you make that use that proficiency.

Arcana Proficiency

If you don't have proficiency in Arcana already, you gain proficiency in Arcana.

Wisdom of the Sages

Starting at 10th level, your study of the arcane has imbued your mind and soul with magic.

You gain resistance to psychic damage and advantage on saving throws against being charmed or frightened by magic, being possessed, or having your thoughts read. In addition, your true name can't be discerned by magic, including magic that reads your thoughts.

Finally, you can't be aged by magic, and your natural aging is slowed. For every 10 years that passes, your body ages only 1 year.

Trace the Weave

At 14th level, you discover how to tap into the source of all magic directly, tracing its flow to the origin.

You can use a bonus action on your turn to gain resistance to damage dealt by spells and magical effects, advantage on Intelligence (Arcana) checks, and the effects of the see invisibility and detect magic spells. Also, your wizard spells ignore damage resistances (but not immunities), you know the type of any creature that you can see, and you know what spell any creature is casting if you can see or hear the spell components. These benefits last for 1 minute.

Once you use this feature, you can't use it again until you finish a long rest.