Hi, I've always found melee classes to lack in awesomeness, so I have created one with a tad more slashing around. The designs are strongly based on classes from games and you may recognize some abilities. This is also my first try and balancing might not be perfect, but feel free to comment and/or use in your games! I can't wait for my players to meet their first Dragoon! 

Level	Proficiency Bonus	Traps	Features
1st	+2	1	Normality, Spear Enthusiast, Traps.
2nd	+2	1	Spear Dancer
3rd	+2	2	Lancer Archetype
4th	+2	2	Ability Score Improvement
5th	+3	2	Uncanny Dodge
6th	+3	3	Lancer Archetype
7th	+3	3	Ability Score Improvement
8th	+3	4	Extra Attack
9th	+4	4	Steadfast
10th	+4	4	Lancer Archetype
11th	+4	5	Ability Score Improvement
12th	+4	5	Adamantium Tip
13th	+5	6	Trained body
14th	+5	6	Ability Score Improvement
15th	+5	6	Lancer Archetype
16th	+5	7	Extra Attack
17th	+6	7	Ability Score Improvement
18th	+6	8	Lancer Archetype
19th	+6	8	Redirect Attack
20th	+6	8	Lancer Archetype

 

As a lancer, you have the following class features.

Hit Points

Hit Dice: 1d8 per lancer level
Hit Points at 1st Level: 8 + your Constitution modifier
Hit Points at Higher Levels: 1d8 (or 5) + your Constitution modifier per lancer level after 1st

Proficiencies

Armor: Light armor
Weapons: Simple weapons, Smple ranged weapon, Shields
Tools: None
Saving Throws: Dexterity, Intelligence
Skills: Choose two from Athletics, Deception, Insight, Intimidation, Investigation, Perception, Performanceand Persuasion

Equipment

You start with the following equipment, in addition to the equipment granted by your background:

• (a) a spear

• (a) a shortbow and quiver of 20 arrows

• (a) a burglar’s pack, (b) a dungeoneer’s pack, or (c) an explorer’s pack

• Leather armor

Distance Runner

Add 10 feet to your movement speed.

Spear Enthusiast

You dedicate yourself to a specific weapon type, piercing weapons. You gain proficiency with the following weapons : Javelin, Spear, Pike, Rapier, Trident and all your archetype abilities require the use of at least one of those weapon to be performed.

Traps

As a bonus action you may throw down a trap, up to 30 feet away, that will arm at the start of the next combat round (once every player/creature has finished the current round). The traps have a duration of one minute and will activate as soon as a creature steps on or is placed within a 5 feet radius of the trap's position. Unless stated otherwise, your traps are not hidden. Your lancer level determines the number of traps you have, as shown in the Traps column of the lancer table. You regain every trap points after a long rest.Your selection of traps is as follow. Refer to the spells related to the trap for effect and saves. The traps are considered spell while calculating attack, damage and effect and you must use your modifiers for the rolls. For positioning purposes, you may choose as the trap's center of origin(caster) : the trap's initial location or the target's location. The traps damage and effect do not improve unless stated otherwise. (For the Dragoon and impaler, the Thunderwave Trap will casts a level 1 Thunderwave spell using your modifiers as if you were using a level 1 spell slot at all times.) Only one trap of each name can be placed down at the same time. If a second trap of the same name is placed, it deactivates the first trap immediately. Traps dissipate after one minute and may not be collected to increase your number of traps remaining.

Entangle Trap : Entangle spell (Level 1)

Faerie Fire Trap : Faerie Fire spell (Level 1)

Thunderwave Trap : Thunderwave spell (Level 1)

Fog Cloud Trap : Fog Cloud spell (Level 1)

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

Spear Dancer

As a bonus action you may use the Dash action. Once you choose your Lancer Archetype, you gain an extra action choice to perform with Spear Dancer.

Lancer Archetype

At 3rd level, you choose an archetype that you strive to emulate in your combat styles and techniques. Choose Dragoon, Impaler or Trap Master, all detailed at the end of the class description. The archetype you choose grants you features at 3rd level and again at 6th, 10th, 15th, 18th and 20th level.

Ability Score Improvement

When you reach 4th level, and again at 7th, 11th, 14th and 17th 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.

Uncanny Dodge

Starting at 5th level, when an attacker that you can see hits you with an attack, you can use your reaction to halve the attack’s damage against you.

Extra Attack

Beginning at 8th level, you can attack twice, instead of once, whenever you take the Attack action on your turn.

The number of attacks increases to three when you reach 16th level in this class.

Steadfast

Beginning at 9th level, you are able to resist movement effect by planting yourself and your spear in the ground. Whenever you are subjected to a movement effect not instigated by your, you may choose to resist the effect and stay at the same location. (If someone tries to push or pull you, you may resist the effect.) You also gain advantage on physical Strength and Dexterity rolls against another creature and you may choose to be unaffected by your own traps.

Adamantium Tip

Beginning at 12th level, you become so adept and precise with your piercing weapon that while wielding it, you ignore piercing resistance (immunity still applies) of your target.

Trained body

By 13th level, you have acquired greater physical strength. You gain proficiency in Strength saving throws.

Redirect Attack

Starting at 19th level, when a foe attacks you with a melee weapon and misses, you can use your reaction to redirect it's attack towards another creature within it's reach. When the attack is launched, you roll the attack die using your modifiers instead of the creature initially attacking you.

 

Dragoon

Favoring an offensive type of fighting, the Dragoon performs astonishing acrobatic feats to deal heavy damage to it's ennemies. His fighting style is hard to master, but extremely rewarding when used by a patient warrior.

Spear Dancer

When you choose this archetype at 3rd level, your Spear Dancer ability allows you to choose the Disengage action and you gain proficiency in the acrobatic skill.

Spear Artist

Beginning when you choose this archetype at 3rd level, your piercing weapon gains the finess property, when wielded by you,.

Spear Ram

At 3rd level, you dedicate yourself to the offensive path of the dragoon. If you move 15 feet in a straight line towards your target before attacking, you end your run in a running jump and add your acrobatic modifier to your damage instead of your ability modifier. This bonus applies to this first attack made after the run. To gain the bonus effect a second time, you must run another 15 feet in a straight line before attacking.

One on One

Beginning at 6th level, when your target has no ally or enemy, other than you, within 20 feet, gain advantage on all your attacks against that target.

Ravage

At 10th level, after dealing damage with Spear Ram, roll an Acrobatic die with a DC of 15. On a successful roll, you launch yourself in the air and perform your following attack on the same target. This attack automatically activates Spear Ram and the Acrobatic damage modifier of Spear Ram is doubled when calculating damage. If you performed 2 or more successful Spear Rams on the same target during this turn, Ravage has an Acrobatic DC of 20, and, on a successful roll and hit, the acrobatic damage modifier is instead quadrupled. If you miss either the attack roll or the acrobatic roll, you land on the floor and may resume your attacks, if you have any remaining. Ravage is still part of the same action as your attack action.

Dual Slash

Beginning at 15th level, you can use your action to make a melee attack against two creatures within your reach, with a separate attack roll on each target. To calculate damage, use one weapon damage die for each attack you could have performed that turn. Spear Ram may apply once. You can’t use this feature again until you finish a long rest. (For a 16th level Dragoon with a +1 spear, after running in a straight line for 15 feet, the damage would be 3d8+3+1xAcrobatic modifier and the damage would be the same on each targets hit successfully.)

Tendon Rip

At 18th level, your mastery of piercing weapons is unparalleled, on a successful Spear Ram, your target must make a constitution save or become maimed and gain disadvantage on all it's physical attack rolls on it's next turn.

Epic Movement

Starting at 20th level, you gain the flying movement type.

 

Impaler

The Impaler is at home in the middle of a battlefield. Using a combination of traps and piercing weapon abilities, he encourages his foes to focus him at a terrible hidden price. No one runs away from an Impaler.

Spear Dancer

When you choose this archetype at 3rd level, your Spear Dancer ability allows you to choose the Dodge action.

Bonus Proficiencies

When you choose this archetype at 3rd level, you gain proficiency with medium and heavy armor.

Weapon Charge

At 3rd level, you dedicate yourself to the defensive path of the Impaler. You attach your weapon to a chain and may throw it to a location (within a number of feet equal to your speed) or make a ranged attack against a target (within a number of feet equal to your speed) and then pull yourself to your weapon's location (or nearest). Aiming at a location does not consume your action move. The action of pulling yourself disables movement restrictions and consumes your entire move action.

Impaling Weapon

Beginning at 6th level, when wielded by you, your piercing weapon gains the reach property and slashing is added to it's damage type. (For a target to resist your weapon damage, it would have to be piercing and slashing resistant.)

Trap Artist

At 10th level, as a bonus action, upon landing a Weapon Charge, you may lay a trap down within 5 feet of you. The trap will activate at the end of your current turn if a creature other than you stands within it's reach. You may choose to have traps layed using Trap Artist not to affect another creatures.

Challenging Shout

Beginning at 15th level, you can use your action to challenge every foe within 20 feet of you gaining 5x the number of enemies hit as temporary hit points and debuffing your targets. For their next turn, every debuffed target has disadvantage on all of it's actions and saves when they are not directed at you and everyone but you have advantage on their saves against the debuffed targets.You can’t use this feature again until you finish a long rest.

Heavy Retaliation

At 18th level, whenever you take damage from a creature within your reach, you can use your reaction to make a melee weapon attack against every creature within your reach. You also gain resistance to the type of damage you received until the end of your next turn.

Impale

Starting at 20th level, when you hit a creature with a melee attack, you may reduce it's speed to 0 for it's next turn.

 

Trap Master

Master strategists, Trap Masters use advance tactics to disrupt the battlefield to the inconvenience of it's enemies. Controlling it's targets with the use of powerful traps and combos, he inflicts much more harm than usually anticipated.

Spear Dancer

When you choose this archetype at 3rd level, your Spear Dancer ability allows you to choose the Disengage action and you gain proficiency in the arcana skill.

Trap Artisan

Starting at 3rd level, you can use your traps as a regular action as well as a bonus action. Your traps are invisible and you may throw them down without a sound. You may choose to have your traps not affect up to two creatures within their range.

Trap Combo

Beginning at 6th level, everytime you hit a creature with your weapon, it gains disadvantage on it's saving throw against the next trap detonation it suffers and takes your Arcana modifier as extra piercing damage upon detonation. This effect stacks with itself up to the number of attacks you have per turns and lasts 1 minute.

Craftsmanship

At 10th level, you gain access to other traps and your traps improve in efficiency, arming themselves at the end of your current turn and gaining improvements as follows. At the end of each battle, once there are no ennemies in sight and if you have used at least one trap during the battle, you may make an Arcana check DC 15 to recover one trap, increasing your number of traps remaining by one.

Improvements :

Entangle Trap : Affected creatures have disadvantage on the save DC.

Faerie Fire Trap : You may choose up to two targets within the spell area to be unaffected by the spell.

Thunderwave Trap : Damage improves as if cast with higer level spell slots. Instead of using spell slots, use your Traps total as shown in the Traps column of the lancer table. (A level 13 Lancer has access to a total of 6 traps, therefor, you can cast this trap and calculate the damage as if it was cast using a spell slot level 6.) The trap still consumes a single trap charge.

Fog Cloud Trap : Heavy fog reduces the speed of every creatures inside by 10 feet.

New traps :

Hold Person Trap : Hold Person spell. Effect improves as if cast with higer level spell slots. Instead of using spell slots, use your Traps total as shown in the Traps column of the lancer table. The trap still consumes a single trap charge.

Moonbeam Trap : Moonbeam spell. Damage improves as if cast with higer level spell slots. Instead of using spell slots, use your Traps total as shown in the Traps column of the lancer table. The trap still consumes a single trap charge.

Silence Trap : Silence spell.

Prayer of Healing Trap : Prayer of Healing spell. Healing improves as if cast with higer level spell slots. Instead of using spell slots, use your Traps total as shown in the Traps column of the lancer table. The trap still consumes a single trap charge.

Trap Chain

At 15th level, the radius of your trap's detonation range is increased to 10 feet (the traps will detonate if a creature steps within 10 feet of the trap's position) and may choose if a target entering the area activates the trap. You may also have your trap chain detonate. If the radius of two or more traps ends on adjacent tiles or overlapse each other, they may chain detonate. You may detonate up to three traps as a chain detonation. The effect of each trap is calculated seperatly and affects the target or targets one at a time. You may choose the order in which the traps affect the target and every trap affect the target even if it leaves the trap area during or after calculation of a trap's damage or effect.

Strategist

Starting at 18th level, you may use your action to move up to two armed traps within your sight, up to 30 feet away from their initial position. The new position becomes the initial position of you choose to use this feature multiple times on the same trap. While being repositioned, the traps are deactivated. Traps moved by Strategist will reactivate at the end of your current turn. Every affected creature has it's own save and damage calculation.

Tactical Advantage

Beginning at 20th level, you may use your move action to teleport to one of your active traps within a number of feet equal to your speed and become invisible, as per the Greater Invisibility spell. You may use this skill once per long rest.

 

Oh my god! I'm just glad to know that I am not the only one that desires this to be a thing!
I've always want to make a dragoon and since I am creating my own world to DM one day, I really, really, really want this to be legit.
You've given me such good ideas, thank you so much.
Hope you don't mind if I tweak it a little bit for more story-based build?