The phenomenon known as Wild Magic. The case where magic casters cannot properly control their power and their magic derails, causing unusual and sometimes severe effects. As someone who suffers from Wild Magic yourself, you decided to try and control it. Not to better further your magic, but as a means to enhance your fighting style and maybe have some fun along the way. 

Spellcasting

When you reach 3rd level, you gain enough magic power to begin casting spells on your own.

Cantrips: You learn two cantrips of your choice from the wizard spell list. You learn an additional cantrip of your choice at 10th level.

Spell Slots: The Wild Arcane Knight Spellcasting table shows how many spell slots you have to cast your spells of 1st level and higher. To cast one of these spells, you must expend a slot of the spell’s level or higher. You regain all expended spell slots when you finish a long rest.

For example, if you know the 1st-level spell shield and have a 1st-level and a 2nd-level spell slot available, you can cast shield using either slot.

Spells Known of 1st-Level and Higher: You know three 1st-level wizard spells of your choice, two of which you must choose from the abjuration and evocation spells on the wizard spell list.

The Spells Known column of the Wild Arcane Knight Spellcasting table shows when you learn more wizard spells of 1st level or higher. Each of these spells must be an abjuration or evocation spell of your choice, and must be of a level for which you have spell slots. For instance, when you reach 7th level in this class, you can learn one new spell of 1st or 2nd level.

The spells you learn at 8th, 14th, and 20th level can come from any school of magic.

Whenever you gain a level in this class, you can replace one of the wizard spells you know with another spell of your choice from the wizard spell list. The new spell must be of a level for which you have spell slots, and it must be an abjuration or evocation spell, unless you’re replacing the spell you gained at 8th, 14th, or 20th level.

Spellcasting Ability: Intelligence is your spellcasting ability for your wizard spells, since you learn your spells through studying and memorization. You use your Intelligence whenever a spell refers to your spellcasting ability. In addition, you use your Intelligence modifier when setting the saving throw DC for a wizard spell you cast and when making an attack roll with one.

• Spell save DC = 8 + your proficiency bonus + your Intelligence modifier
• Spell attack modifier = your proficiency bonus + your Intelligence modifier

 

Fighter Level	Cantrips Known	Spells Known	1st	2nd	3rd	4th
3rd	2	3	2	—	—	—
4th	2	4	3	—	—	—
5th	2	4	3	—	—	—
6th	2	4	3	—	—	—
7th	2	5	4	2	—	—
8th	2	6	4	2	—	—
9th	2	6	4	2	—	—
10th	3	7	4	3	—	—
11th	3	8	4	3	—	—
12th	3	8	4	3	—	—
13th	3	9	4	3	2	—
14th	3	10	4	3	2	—
15th	3	10	4	3	2	—
16th	3	11	4	3	3	—
17th	3	11	4	3	3	—
18th	3	11	4	3	3	—
19th	3	12	4	3	3	1
20th	3	13	4	3	3	1

Wild Magic Chance

When you choose this subclass at 3rd level, your control of magic remains imperfect, leading to accidents. Whenever you cast a spell, the DM can have you roll a d20. If your roll is a 4 or below, you must roll on the Wild Magic chart listed at the end of subclass description. Whenever you roll on the Wild Magic chart, your spell automatically fails as well unless listed otherwise.

Wild Arcane Focus

At 3rd level, you possess an item capable of helping you control your magic. Choose an item in your possession. When you are carrying, wearing, or using this item and you roll a d20 to see if your spell goes wild, you may choose to roll with advantage or disadvantage. You can use this feature 3 times a day and you regain all expended uses after a long rest. You are allowed to choose a new item each day however you can only choose a new item once a day.

Wild Opportunities

At 7th level, you begin to take advantage of your random magic. If you cast a spell and it goes wild, you can have a bonus action to take the Dash, Disengage, or Dodge action.

Arcane Control

At 10th level, you begin to control your Wild Magic and allow some breathing room for your spells. Pick 3 of your known spells. Whenever you cast one of these chosen spells and it goes wild, you may choose one of the following options.

• Ignore the Wild Magic and cast the spell as normal
• Roll two separate die for the Wild Magic Chart and use one of the rolls.

You can pick one more spell to add to this ability at 15th level and you can pick another spell to add at 18th level. 

Automatic Chaos

At 15th level, you combine your fighting experience with your magical capabilities. When you use your Action Surge, you can use your additional action to cast a spell at max level without expending a spell slot which is affected by your Wild Magic. Ignore your current maximum of spell slots and cast the spell at max level, meaning a spell such as Burning Hands can be cast at 9th level, instead of 4th level. By using this ability, your spell succeeds like normal however the Wild Magic effect you roll still occurs.

Wild Reflection

At 18th level, you begin to take the magic of others and make it wild. When hit by a damaging spell, you may choose to roll a d20. On a roll of 20 the spell is reflected back at the caster and the spell becomes affected by your wild magic, allowing you to roll on the Wild Magic chart and activate any wild magic based abilities. On a roll of 1 you take double damage from the spell. All other numbers have no effect unless your DM gives them an effect.

Wild Magic Chart

 

01 - 05	For the next minute, whenever you cast a spell it becomes automatically affected by wild magic, regardless of any abilities or effects.
06 - 10	For the next five minutes, you can sense any fey or fiend creature within a 60ft radius of you.
11 - 15	Roll a d20. If your roll is 10 or below, you and everything you are wearing/carrying shrink by 1d4 feet in all dimensions. If your roll is 11 or higher, you and everything you are wearing/carrying grow by 1d4 feet in all dimensions.
16 - 20	The next time a creature lands an attack on you, treat it like a critical hit.
21 - 25	Your spell succeeds and you heal Xd6 Hit Points, with X being your proficiency modifier.
26 - 30	For the next five minutes, whenever you talk to someone, you must give them a compliment or an insult.
31 - 35	Your spell succeeds. Your skin becomes bright pink for the next 24 hours.
36 - 40	An ethereal bard appears, playing a constant melody which can be heard by all creatures within a 60 feet radius of you. The bard cannot be hurt and all objects and spells pass right through them. The bard will follow you for an hour before disappearing.
41 - 45	All spells cast within 60 feet of you automatically target you for the next hour.
46 - 50	Choose a creature you can see. You and the creature swap places.
51 - 55	You gain resistance to all nonmagical forms of damage for the next minute.
56 - 60	You begin to dance uncontrollably for the next minute. All creatures who see you dance must make a Charisma saving throw with against your Spell Save DC. On a fail they begin to dance uncontrollably for the next minute. On a save they resist the temptation and continue as normal.
61 - 65	For the next 12 hours, your voice becomes high pitched and squeaky. After this effect is over your voice then becomes low and deep for an additional 12 hours.
66 - 70	Your spell succeeds. For the next hour all humanoid creatures of the opposite sex who do not personally know you will become attracted to you.
71 - 75	Your spell succeeds. Choose up to three creatures you can see. Each creature takes 1d6 fire damage, 1d6 cold damage, and 1d6 lightning damage.
76 - 80	You see various hallucinations of the DM’s choice for the next hour.
81 - 85	All of your current party members including yourself must roll a d4. Depending on which number they get, they feel the following effect. 1 - The person grows demonic like horns on their head which last for an hour. 2 - The person hands grow sharp and beast like. They can no longer use weapons but their unarmed strikes deal 1d8 slashing damage. This effect lasts for a minute. 3 - The person loses their vision but gains Blindsight with a 60 foot radius. This effect lasts for five minutes. 4 - The person can change their appearance, the same as an Alter Self spell. The person can switch between their normal look and their Alter Self look as a bonus action for the next hour.
86 - 90	All creatures within 30 feet of you regain Hit Points equal to double your character level but also take double damage from all attacks for the next minute.
91 - 95	Your spell succeeds. For the next minute a trail of plants will be created from your footsteps.
96 - 100	Your spell succeeds. The next time you are hit by an attack, you take damage like normal however your attacker takes double the damage they just dealt.