Homebrew Brain in a Jar. Species Details

A Brain in a jar, Normally nothing more then a novelty a shelf decoration in a lab; Normally but not always. Occasionally someone puts a brain in a container with other intentions, making a servant or prolonging his life, or just seeing if they can. But One can't just take any brain and place it into any container, it takes special tools, skills and talented person with a scalpel to make it work.

Right Jar for the Job

The first thing that is decided when making a brain in a jar is the jay it's self. You cannot just dump a pickle jar out and use that, no a brain jar must be carefully crafted either with cutting edge Eberron technology or by powerful ritual magics. Some brain jars are tall and cylindrical while others are bubble-like spheres. They can use complex technology similar to clockwork Homunculus with simple limbs like arms and legs, or are etched crystal layered with protective runes and strong magic augments. No mater how it is made, it is important that the jar can hold the brain and its CSF.

Pick(le)ing your thoughts 

It's important when building a brain in a jar to consider what your putting in the jar. Just the brain? Keeping the eyes? Will you need the nerves for limb control or are you using electrodes? But equally important is who's brain brain is going into the jar, or better said 'Whats'. Not just any brain is compatible, try a troll brain for example... a Peanut floating in a fishbowl trying to regrow a body from scratch? Preposterous! No, when selecting a brain, even your own, you must consider if the host has the mental faculties and intellectual constitution to undergo such a  processor else you might find yourself in the same shoes as Dr. Frank and his flesh golem. So remember, research your brain, who was the owner? Were they a healthy individual? Sane and sound? Are you wiping the memories?  Because these factors can shape not just what a brain in a jar is, but who it will be.

Mind over, whats the Matter?

 When someone becomes a brain in a jar, they find some of the many restrictions they had were more impose by the flesh. Sure you may not be able to feel a warm hug or the refreshing sharpness of a deep breath but weighed against not having to take a breath, the pain of hunger, the aching back and bruises body; who's really the winner? And without a  cumbersome body with its odors and messes, constantly using up all that energy, you can spend your nights learning and definitely not in existential dread staring sleeplessly at a blank wall.

Who they where to who they are.

It is often a concern when one creates a brain in a jar, to consider who they will be. A placid servant, a friend for a lonely child, a wealthy investor running from a ruthless and vicious crime syndicate who has exhausted all of their wiser options. Once this transfer is complete they, like it or not, cannot go back nut this does not mean what they left behind wont follow them forward. Sure the spouse might have a learning curve to get over but hey, its not like they where the ones who sold you out to the criminals in exchange for taking over your grand textile industry... what? OH. sorry. Regardless, this is the chance to re-invent. Want something  strong, how bout an Orc name? Maybe something flashy, High Elven... No one will know, its not like everyone can identify a species by its brain (NOTE: Be alert and very aware of any individual that can identify a species by its brain. That knowledge is only gained two ways.)

Brain in a Jar. Traits

A well made Jar is sturdy and strong, a well made Brain.. is wrinkly and soft.

Combat maneuver

Being a Tiny thing in a world of not tiny things has many perils, all of which you have accounted for and are ready to avoid. As a reaction a critical hit against you becomes a normal hit.

Ability Score Increase

A brain can't just be put in a jar, it has to be exceptionally tough in one regard or another. Select Constitution, Wisdom, or Intelligence and increase it by 2,  the other two attributes are increased by 1.

Age

Generally speaking, if properly preserved, A brain in a jar should never expire...err Age. Should never age. Not Even Orc Brains.

Alignment

Being a brain in a jar plays little on being good or evil. It really depends on who you were, or in a such as your brain simply being used as a processing center for a mighty machine... who your maker wants you to be.

Size

A jar big enough for a brain really doesn't take up much space even with your accouterments, your starting size is tiny.

Language

You know how to speak, read and write in common and 1 other language. Whether you can, depends on your jar.

Healthy is a construct

Your well being is based based on your Jar instead of a body. You have to Hitpoint pools, one for the brain and one for the jar. When calculating any Hit points gained when gaining a level (including 1st), Your brain HP is increased by your constitution (min 1), while your jar's HP is increased by the die (or die average).

When being targeted by an attack or magical effect, The Jar's HP must be depleted first and excess damage does not carry over to the brain. When the Jar is at 0hp, your movement becomes 0 until at least 1 hp is restored to the jar.

The only way to regain HP for your Jar outside a short or long res is; as a bonus action, once per turn, making a tinkers tool check (DC 10) restoring 1d4 HP or by having the spell mending spell cast on you, restoring 1d6 HP (+d6 at level 5,11,17) . Another creature attempt the tinkers tools check (DC 15) to repair you as an action. If a creature has any ability to that allows them to repair constructs they may use that to repair you.

During a short rest you may make a tinkers tool check (DC10) to attempt to repair your jar, on a success you may spend you hit die as you would normally. On a failed check you regain 1/2 the hit die.

A body of glass and steel

Your jar may be an armoured shell that will withstand most damage both physical and magical, but it is just a container made of inorganic materials, filled with liquid, with a brain floating in it.

• You have advantage on saving throws to resist magical effects. When you are subjected to an effect that allows you to make a saving throw to take only half damage, you instead take no damage if you succeed on the saving throw, and only half damage if you fail.
• You are immune to Exhaustion, poison, poison damage.
  
• You are vulnerable to thunder, cold and lighting damage damage.
  
• Magical Necrotic damage bypasses Jar health damaging your brains health directly.

Won't fix it's self.

You wont always have someone around to repair your jar. You gain proficiency with tinkers tools and know the cantrip mending. When using the Mending spell targeting self, it can be cast without any of its components.

Barely any Brain Drain

Being a brain in a jar has a so many excellent perks. During a long rest you only need 2 hours for sleep, refreshing your brain fluids and important self repairs. During this time you heal as any creature would normally. You may spend the rest of your long rest doing light activities such as preparing spells or sharping swords or staring at you party, sleeping so soundly in their nice cozy bodies.