Student of Chronomancy

A subschool of Transmutation with heavy crossover into Divination, Chronomancy is time magic--altering time, creating time, freezing time, and moving and looking through time. Using chronomancy, a wizard can reduce or extend a casting time, broaden the powers of certain divinations, undo recent events, and eventually step outside of the normal flow of time for a while. 

Chronomancer Initiation

 You have forsworn the traditional structure of the eight schools of magic to pursue the hidden art of chronomancy.  

You learn the [spell[True Strike[/spell] cantrip. If you already know this cantrip, you may select a different cantrip from the Divination or Transmutation schools.

Whenever you gain a level in the Wizard class, one of the two spells you learn must be from the Divination or Transmutation schools. The other spell can be from any school. Other spells you learn (i.e., those that you find and inscribe into your spellbook) can be from any school. While many Necromancy spells look like they contain Chronomancy, they universally operate by altering the metabolic processes for the body and not by changing the body's relationship to the flow of time. 

Additionally, the spells Augury and Divination are considered to be on your Wizard spell list. Other Wizards cannot copy these spells from your spellbook unless they also have them on their Wizard spell list.

Prognostication

Starting at 2nd level when you select this school, you learn how to look a short duration across time, but only for actions you take. You can only see one result of the action you examine, and the action must be your own.

Use Prognostication as a bonus action on your turn before taking your action, which can be a weapon or spell attack requiring an attack roll. State the parameters for your planned action at this time and identify all the targets. Then roll one of the attack rolls that you would make with the action. The DM will tell you if your action will hit or miss that target. You do not see the results of any saving throws your target might make, nor any consequences of a hit or miss (like observing a target drop to 0 hit points)--you only learn if the attack hits or misses.

At this time, you can choose to proceed with the action (and roll the other attack rolls for your action, if any) or you can abort your action to do something else. If you abort, you create an internal paradox in the time stream and suffer 1d10 psychic damage which cannot be resisted, and you must change the parameters for your planned action or choose a different action. If you do so, you roll any attacks normally.

For example, a Chronomancer plans to cast [Tooltip Not Found] at three of four enemies. First, she uses Prognostication as a bonus action, declaring the three kobolds she plans to target and rolling one of the attack rolls of her choice. She determines that the attack she foresaw would miss, and opts to abort the planned action, taking 1d10 psychic damage. She then uses her action to cast Scorching Ray at the kobold she foresaw she missed, one she planned to attack but didn't Prognosticate, and the last kobold she previously did not target. Having changed the parameters of her spell, she now makes all three attack rolls normally, which could include hitting the kobold she originally saw she would miss, because she changed what she did when she made that attack.

 You can use Prognostication twice per extended rest.

Time Dilation

Starting at 6th level, you learn spells that control the rate time passes to others. You add the <spell>haste</spell> and <spell>slow</spell> spells to your spellbook. These spells are always considered prepared for you. If you already know one (or both) of these spells, you can select a new spell (or two, if you knew them both) to add to your spellbook.

In addition, because of your focus and study on the flow of time, neither of these spells requires concentration when you cast them regardless of the source (spell, magic item, etc.). 

Temporal Scrying

At 10th level, the invisible sensors you create when casting Clairvoyance, Arcane Eye, and Scrying are not bound by the present time.  You can use Temporal Scrying to add a temporal component to one of these spells once per long rest.

These divinations have different time targets they can perceive. Clairvoyance can be cast one week into the past or one day into the future. Arcane Eye can be cast one month into the past or one week into the future. Scrying can be cast one year into the past or one month into the future. The Chronomancer chooses what time they will observe when they cast the spell, and they observe an amount of time equal to the spell's duration (all of which are concentration spells). 

Additionally, these spells can be cast using a higher level spell slot. Every two levels the spell is upcast moves the time duration one step up on the following chart. 

• Up to one week in the past or one day into the future
• Up to one month in the past or one week into the future, and double the duration of the spell. 
• Up to one year in the past or one month into the future
• Up to one decade in the past or one year into the future, and double the duration of the spell
• Up to one century in the past or one decade into the future

Using this magic is not without risk. Each creature observed in the past that detects the scrying sensor can potentially set off a cascade of consequences for the viewer, especially if they know of the Chronomancer or will one day encounter them before the casting. For every creature that detects the sensor, the caster takes 3d10 psychic damage that is unpreventable by any means. If the observer is a Chronomancer, then the damage is force damage instead. While these observations will not change the caster's past, they might change the future by preparing groups for the Chronomancer's interference. Alternatively, if the target of a Scrying spell makes their save, the caster also takes this damage (but cannot be further observed, as the scrying sensor does not manifest).

Visions of the future are notoriously unreliable, as knowledge of the future changes it. However large scale events tend to align to prediction even if specific details change. Think of time as the flow of a river, with the directions it travels as the preordained events fated to happen and the contents of the river as the people who happen to be there bringing the future about. Most human events are much like the tossing of pebbles into that river. It would take a very significant object to divert the river, but not much effort to pluck a fish from the water. 

 

Time Determinism

Sometimes, time is of the essence and nobody understands this better than the Chronomancer. At 14th level, you learn to cast your spells back in time, but only by a few seconds.

You use your reaction in the present when you wish the spell to take effect. You must expend a spell slot equal to or higher than the level of the spell you will cast in the future. That effect takes place immediately. At the beginning of your next turn, you cast the spell that already went into effect. You must assume concentration of any spell that requires it at that time, but you do not concentrate on the spell before you cast it. 

The dangers of creating a temporal paradox through this process are very real and substantial. If you are prevented from casting the spell at the start of your turn or choose not to do so, you expend the spell slot or one capable of casting it and the spell goes off anyway but you are stunned for 1 minute, take 1d10 psychic damage per spell level of the uncast spell that is unpreventable by any means, and lose the ability to initiate or maintain concentration until you finish a short or long rest. At the end of each of your turns, you can make an INT save against your own spell DC to recover from being stunned, but you cannot initiate concentration until you finish a short or long rest. Because the spell must be cast at the start of your turn, these consequences take effect instantly when you attempt to do anything other than cast the spell. 

You can use Time Determinism a number of times per long rest equal to your INT modifier, minimum of 1.