A man in a red suit dashes into combat, so fast that he becomes a blur. His fist bursts with lightning as it crashes with inhuman speed into an orc's face.
An elf moves so fast she seems to be in two places at once. A sword swung at one of those places reveals that it was merely an optical illusion as she runs behind her attacker and punches him in the back of the head.
A half-orc runs into combat with unbelievable speed, seemingly insubstantial as he phases through enemies and obstacles.
A speedster's power comes from the Speed Force. This mysterious entity allows a combination of physical changes and time distortion to let its chosen move at incredible speed. The blessing of the Speed Force also takes care of certain realities like air resistance, the need to breathe, inertia, and various strains on the body that would prevent moving at such speeds. The most potent weapon of the speedster is actually the lightning charge they build via static electricity when moving, another of the obstacles the Speed Force protects them from.
The consciousness or lack thereof of the Speed Force is unknown. It is unknown if it has a morality, motives, or goals, where it may be, or if it is a tool of some godlike being. Whatever the case, becoming a speedster does not come by choice; they are chosen by the Speed Force or whoever or whatever controls it. In at least one case, this transformation took the form of being struck by lightning.
The lightning and speed may be the speedster's only abilities, but they use them in a variety of ways, including ways that don't seem to be functions of either. The nature of their transformation may leave speedsters believing they were chosen for a higher purpose, but whatever it may be is up to the individual to discern.
Creating a Speedster
Speedsters can come from any background and have any motivation. They may use their power frivolously or responsibly, and have no real connection to each other. Many have their speed leak into their personality; always in a rush, quick to anger and forgive, fast with a comeback, etc.
A speedster relies on their Strength and Dexterity to accomplish most of what they do, and either one could be their best score, depending on the player's preference and the role they want to fill, but Dexterity would be the best choice most often.
Level Proficiency Bonus Movement Increase Features 1st +2 - Speed Force, Static Charge 2nd +2 +5 feet Unarmored Movement, Adoit 3rd +2 +5feet Power Focus 4th +2 +10 feet Ability Score Improvement 5th +3 +10 feet Extra Attack 6th +3 +15 feet Power Focus Ability 7th +3 +15 feet Extreme Dash 8th +3 +20 feet Ability Score Increase 9th +4 +20 feet Lightning Refexes 10th +4 +25 feet Power Focus Ability 11th +4 +25 feet Extra Attack II 12th +4 +30 feet Ability Score Improvement 13th +5 +30 feet Lightning Hands 14th +5 +35 feet Power Focus Ability 15th +5 +35 feet Ludicrous Speed 16th +5 +40 feet Ability Score Improvement 17th +6 +40 feet Lightning Recovery 18th +6 +45 feet Ability Score Improvement 19th +6 +45 feet Power Focus Ability 20th +6 +50 feet Extra Attack III
As a speedster, you gain the following class features:
Hit Dice: 1d8 per speedster level
Hit Point: 8 +your Constitution modifier
Hit Points at Higher Levels: 1d8 (or 5) + your Constitution modifier per speedster level after 1st
Weapons: Simple Weapons, short swords.
Tools: Disguise Kit
Saves: Dexterity and Intelligence
SKills: Choose two from Acrobatics, Athletics, Investigation, Sleight of Hand, and Stealth
You start with the following equipment in addition to the equipment granted by your background:
(a) a shortsword or (b) any simple weapon
(a) a dungeoneer's pack or (b) explorer's pack
a set of fine clothes
Beginning at 1st level, you move faster than normal for your species. Any time you move, you may treat your walking speed as doubled, but you must move in incremenets of 10 feet instead of 5 feet, i.e., you move ten feet in one direction for each square of movement you normally have. You can also change the increments to 15 or 10, alternating at your option, but you gain 1 level of exhaustion at the end of your turn.
As you move, you build up a static charge which you can unleash on your enemies. Beginning at 1st level, you gain one point of static charge for each five feet of movement you make in a turn over thirty feet. You can discharge this energy on a target you hit with an unarmed strike, dealing 1 point of lightning damage per point of static charge. Otherwise, half of your stored static charge disappears at the beginning of your turn, rounded up. The amount of static charge you build is not based on the total movement used, but the distance between your starting point and ending point, and difficult terrain only confers one static charge point for each five feet moved. You always discharge the entirety of the static charge points when you use them for any purpose. If you discharge your static charge points and then move any further that turn, you build up more static charge points.
Beginning at 2nd level, your walking speed increases when you are not wearing armor or wielding a shield. The class table details the amount in the column labeled "movement increase."
Beginning at 2nd level, your speed is not just in your movement. When you take the dash action, you can do one of the following as a bonus action: help, make an unarmed strike, interact with an object, dodge, or disengage. You may take two bonus actions in a turn of any type you are normally able to make, but you gain a level of exhaustion at the end of your turn.
Even though the speedster technically has only one special ability, they focus on different aspects of that ability. At 3rd level, you choose to focus on either the time distorting effects of the Speed Force or manipulating the lightning, becoming either a Distorter or a Lightning Master, and gain more abilities from your power focus at levels 6th, 10th, 14th, and 19th.
Ability Score Improvement
When you reach 4th level, and again at 8th, 12th, 16th, and 18th level, you can increase one ability score of your choice by 2, or you can increase two ability scores of your choice by 1. As normal, you can't increase an ability score above 20 using this feature.
Beginning at 5th level, you can attack twice, instead of once, whenever you take the Attack action on your turn. The number of attacks increase to three when you reach 11th level in this class and to four when you reach 20th level in this class.
Beginning at 9th level, you may use your reaction to make an unarmed strike in response to being attacked in melee as long as you have at least 1 point of static charge stored.
Beginning at 7th level, you may move up to triple your walking speed when you take the dash action.
Beginning at 13th level, when you take the attack action on your turn, you may forgo one or two of your attacks to take an equal number of the following actions: dodge, disengage, interact with an object, or help.
Beginning at 15th level, you may take another turn in combat, at your normal initiative -10. If you do, you gain a level of exhaustion.
Beginning at 17th level, when you roll initiative, remove one level of exhaustion
When you take the Lightning Master power focus at 3rd level, you gain the discharge ability. As an action, you may expend all static charge points to deal damage to all creatures within 10 or 15 feet of you (your choice) equal to half the static charge points expended, with a Dexterity saving throw for half damage equal to 8 + your proficiency bonus + your Constitution modifier.
Beginning at 6th level, you gain the Ball Lightning ability. When you have built up five or more static charge points, you can throw a ball of lightning as a ranged attack that takes the place of one normal attack. It has a maximum range of 30 feet. It deals one point of damage per static charge point you had stored.
Beginning at 10th level, lightning damage from your static charge abilities ignores resistance to lightning damage, and you gain resistance to lightning damage.
Beginning at 14th level, you gain 3 points of static charge for each 10 feet of movement.
Master of Lightning
Beginning at 19th level, you only lose a quarter of your static charge, rounded down, at the beginning of your turn. You also gain immunity to lightning damage.
When you take the Distorter power focus at 3rd level, you learn to make a quantum double of yourself. As an action, you spend 10 points of static charge and make a double of yourself and you each must move to a different square. This is an exception to the rule that static charge abilities always use all the available static charge. As a reaction to being damaged or suffering any effect from a failed saving throw, you may collapse the double who was damaged and have them disappear, cancelling all damage and leaving the other double the sole one remaining, but otherwise you share the same hitpoint pool. When you are doubled, each double can only move, speak, and use their action to dodge, interact with objects, or attack once (even after you can make multiple attacks per action) on your turn, and they can only be as far apart as your bonus movement speed from your Speed Force ability when you end your turn, or you must choose one to collapse, but they cannot occupy the same square. If both doubles threaten the same creature, you can collapse one double to gain advantage on the first attack roll made against that creature, as long as it is before the beginning of your next turn. Each double starts with the same amount of static charge points as you had when you split, but thereafter they are tracked separately.
Beginning at sixth level, your speed extends to your body's ability to repair itself. You may use your static charge to heal yourself as a bonus action, regaining 1 hitpoint per 5 points of static charge you expend. All of your static charge is discharged, but you cannot gain over your maximum hit point total. You also gain one level of exhaustion.
Beginning at 10th level, you learn to use your speed to vibrate your molecules around the molecules in solid objects. After moving at least 10 feet, you treat creatures and objects as difficult terrain when moving through them, and you no longer provoke opportunity attacks from moving. Regardless of how many creatures or objects you move through, you gain one level of exhaustion at the end of your turn.
Beginning at 14th level, your quantum duplicates can be up to 500 feet apart.
Beginning at 19th level, after creating a quantum double, one of your doubles can create a third quantum duplicate as an action. You cannot create a fourth quantum duplicate.