You have mastered the art of moving fast and have obtained some very speedy abilities

Speed Ability Groundwork

You cant multiclass in or out of this subclass

When you do damage (except for your charge of wind ability) you deal only half the damage you would've done rounded down

When you pick this subclass your base speed goes up 10 ft

Speed Score:   you gain a speed score that is a separate ability score like strength or wisdom.

Your speed score is your base movement speed in feet. For example, your base movement speed might start at 30 ft (speed score of 30) and increase as you level up.

Your speed modifier is calculated by dividing your speed score by 10, rounded down. For example if your speed score is 30, your speed modifier is +3, if your speed score is 25, your speed modifier is +2.

Note: Your speed score is not affected by magical items or class features that modify movement speed

Speed based skills: You can add half your speed modifier (rounded down) to your acrobatics, athletics, and stealth checks.

Quick reflexes: you ad half your speed modifier to your initiative rolls (rounded down)

Surge of Speed

As a bonus action you can activate Surge of Speed for 1 minute. (once per long rest)

You gain the following benefits:

Bonus Action Dash or Disengage: You gain AC equal to half your speed modifier For example, if your Speed modifier is +4, you gain +2 AC while surge of speed is active.

Extra Attack: You can make one melee attack as a bonus action each turn. This attack uses your Speed modifier for both the attack roll and damage modifier, instead of your strength or dex modifier.

Speed Based Abilities

You gain the following abilities:

Speedy Feint: As a reaction, when a creature attacks you, you can use your speed modifier to add +1 to your AC against the triggering attack. If the attack misses, the creature becomes distracted and has disadvantage on their next attack roll. This ability can only be used once per short rest.

Quick Adaptation: You can use a bonus action to gain advantage on a saving throw related to movement (e.g., avoiding a grapple or escaping an area-effect) for 1 minute. This ability can be used once per short rest.

Speed Burst: You can increase your movement speed by 20 ft for 1 turn. However, you take damage equal to your speed modifier (rounded down) as the effort of moving faster takes a toll on your body. You can use this ability once per short rest.

Master of Speed

Speed of Thought: You can use half of your speed modifier, rounded down, to boost intelligence-based checks like investigation, arcana, and insight, as your reflexes translate into fast decision-making.

Charge of the Wind: When you move at least 30 ft in a straight line toward a creature, you can choose to slam into the enemy with great speed. You deal thunder or bludgeoning damage equal to your speed modifier + 1d6 per 10 points of speed score (rounded down). You also take 1 third of the damage you dealt, rounded up. You can use this ability twice per short rest.

 

Need for Speed

You gain the following abilities:

Always First: You can automatically go first in initiative order at the start of combat

Running Rampage: You can take an additional turn immediately after all other creatures have taken their turn in the current initiative order. After taking your turn, you gain 2 level of exhaustion. You can use this ability once per long rest.