Medic

In times of war, many without the natural aptitude to magic are needed on the frontlines to heal and restore their fellow comrades. These individuals are known by many names, but the forces they serve call them simply medics, a testament to their ability to restore others even in the war-torn fields and crowded combats. Not all field medics have seen combat, of course. Those that have returned from the frontline share their craft with those who wish to learn it, so it has evolved the practice into a widely respected art across the lands.

Whatever the case however, medics train to both dispatch enemies and repair allies, learning to become skilled with every application of a blade, with their knowledge of humanoid anatomy making them excellent allies at the same time they strike with surgical precision.

The Right Tools for the Job

When you choose this archetype at 3rd level, you have learnt how to utilize nonmagical medical supplies. You gain proficiency with the Medicine skill if you don’t have it already, and your proficiency bonus is doubled for any check you make with it. You may use Intelligence as your ability modifier for this skill instead of Wisdom (change manually in the character sheet, also, DM's Discretion).

Additionally, you gain proficiency with the herbalism kit, and whenever you interact with a healer’s kit on your turn, you may do so as part of your Cunning Action instead.

Triage Healer

Also at 3rd level, you learn how to concoct a special medicine only you or other medics can create, and how to apply it in high pressure situations. As an Action or as part of using your Cunning Action to Dash and move within 5 feet of a creature, you may quickly administer emergency medicine to a creature within 5 feet of you (that creature may be you). The creature regains a number of hit points equal to one roll of your Sneak Attack dice + your ability modifier used for the Medicine skill, up to a maximum to the damage the creature took since the beginning of the turn prior to your last turn.

Once you've applied this emergency medicine to a creature, they can't benefit from it again until they finish a short or long rest.

Clarification: For example, as a 3rd level Medic Rogue with a Dexterity score of 18, a creature regains 2d8 + 4 hit points from your roll. So, on an average roll, you can cause a creature to regain 12 hit points. If a creature has taken 20 damage since the beginning of the turn prior to your last turn, meaning 2 turns ago, you heal them for the full 12. However, if they have instead taken 8 damage during these 2 turns, even if their hit points are much lower than their hit point maximum, you can only restore 8 hit points to the creature.

Medical Analysis

At 9th level, your knowledge of anatomy lets you analyze all sorts of bodies and pry them open of information for your benefit. As an action, you can analyze the body of a creature within 5 feet of you, whether dead or alive.

If the creature is dead, you can spend up to 1 hour investigating their corpse, allowing you to learn information about their demise, provided the corpse is in condition to be examined. You learn the cause of death, an estimate of the creature's death, an estimate of how long ago the creature died, its creature type, and if it was afflicted by any magical effects or spells at the time of death.

If the creature is alive, you can attempt a (Medicine) check, contested by the creature’s Constitution saving throw. If you win the check, the creature becomes stunned until the beginning of your next turn, as you strike at specific nerves in their body, and you learn the following information about the target: damage vulnerabilities, damage resistances, damage immunities, and condition immunities.

Once a creature fails the saving throw, you can't use this feature again until you finish a short or long rest.

First Responder

Starting at 13th level, your medical capacity increases greatly. You gain the following features:

Emergency Reflexes. Whenever an allied creature drops to 0 hit points, you may use your reaction to move up to your speed without provoking opportunity attacks, as long as you move towards your ally. If you move within 5 feet of the ally this way, you may use your Triage Healer feature on them (no action required). The first time after each short rest that you heal a creature with this feature, they aren't negated from benefiting from Triage Healer until they finish a short or long rest. 

Improved Medicine. Whenever a creature regains hit points from your Triage Healer feature, if they are poisoned, that condition ends on them. In addition, you can either end one effect reducing the target's maximum hit points, end a disease, or end the blinded, deafened, paralyzed or stunned condition on them. Once a creature has a condition, disease or effect removed from them this way, they can't benefit from this feature again until they finish a short or long rest.

Medic Extraordinaire

When you reach 17th level, you've learnt to infuse your medicine with a shot of adrenaline.  Whenever a creature regains hit points through your Triage Healer feature, they may use their reaction to take an Action. If you use this feature on your turn, it doesn't take use your reaction.

Additionally, creatures can be healed with your Triage Healer feature twice instead of once, before they must finish a short or long rest to be healed by the feature again.