Mad Science

Barbarians that find themselves on the Path of Mad Science often end up there quite by accident. Some resort to using themselves as test subjects for experimental potions, only to find themselves transformed into a hulking beast. Others were exposed to bizarre chemicals and found themselves with strange power. Others still find that their transformation is so horrifying they flee to hide from those they know. In battle, these transformations can make those who follow the Path of Mad Science a force to be reckoned with.

Your barbarian might consider their powers to be a horrible failure, or they may be proud of their success. Your barbarian and their transformation might even have wholly different personalities that disagree with each other. You may even already be fully transformed, only vaguely identifiable as your race of origin.

 

Bonus Proficiency

When you choose this path at level 3, you gain a proficiency in one skill that uses Intelligence. You also become proficient in Intelligence saving throws. If you already have this proficiency, you instead gain a proficiency in Charisma or Wisdom saving throws (your choice). However, you lose these proficiencies while you are raging.

Wrathful Mutation

When you select this path at 3rd level, the product of your experiments causes your body to undergo mutations and bring new powers to the surface. Your physical features change when you activate your rage, making you almost unrecognizable. This could be roleplayed as consuming or injecting chemicals, losing control of yourself to your primal instincts, or any way that best fits the kind of person your Barbarian is. 

Choose one of the following transformations. Your choice will grant you additional traits at 6th and 14th level. Once you have chosen your transformation, you may not swap it out between levels.

Regenerative Transformation. When you activate your rage, you regain hit points equal to half your Barbarian level, rounded up, at the end of each of your turns. You also become resistant to necrotic damage while you are raging. 

Animalistic Transformation. When you activate your rage, you grow claws, fangs, spines, or some other sharp mutation that you may attack with. If a creature enters or ends its turn in a space within 5 feet of you, you may make an attack with your mutations as a reaction. You are proficient with these weapons, and they deal 1d4 slashing damage. The damage increases when you reach certain levels in this class, increasing to 1d6 at 6th level, 1d8 at 10th level, 1d10 at 14th level, and 1d12 at 20th level.

Frightful Transformation. When you activate your rage, the shock of your sudden transformation is enough to frighten unprepared creatures. After you activate your rage, other creatures within 15 ft. that can see you must each succeed on a Charisma saving throw (DC 8 + your proficiency bonus + your Constitution modifier) or become frightened of you until the end of your next turn. In addition, you have advantage on any intimidation checks you make. You become immune to the frightened condition while raging.

Advanced Mutation

At 6th level, the unstable concoction flowing through your veins grants you even more power. You gain one of the following traits, based on which transformation you chose as your Wrathful Transformation. 

Regenerative. While you are raging, you become immune to poison damage, as well as the poisoned and disease conditions. If you are poisoned or suffering from the effects of a disease when you begin your rage, the condition ends for you. In addition, if you choose to end your rage early, you regain a number of hit points equal to half your barbarian level + your Constitution modifier. You also gain a resistance to poison and necrotic damage even when not raging. 

Animalistic. While you are raging, you ignore difficult terrain, and climbing or swimming costs you no extra movement. 

Frightful. While you are not raging, you may briefly activate your transformation to frighten other creatures. You may use this feature to give yourself advantage on an Intimidation check. You may also use this feature to impose disadvantage on an attack roll against you (you must use this feature before you know if the attack hits or misses). You may use this feature a number of times equal to your Constitution modifier (minimum of 1).

Alchemical Breakthrough

At 10th level, your familiarity with the compound that caused your transformation allows you to replicate it, in a temporary form. During a long rest, you may forfeit the effects of your rest to stay up and create a number of chemical-filled vials equal to your intelligence modifier. Consuming the compound yourself will have no effect, but if given to another creature, they may share a small amount of your power for 1 minute. The type of compound you can create corresponds to the transformation you chose as your Wrathful Transformation. 

Regenerative. The creature regains a number of hit points equal to half your barbarian level (rounded up) at the end of each of their turns. They also become resistant to poison damage.

Animalistic. The creature gains advantage on Perception or Survival checks relying on hearing or smell. They also ignore the effects of difficult terrain. 

Frightful. The creature gains advantage on Intimidation checks, and is immune to the frightened condition.

Empowered Transformation

At 14th level, you gain an unparalleled mastery over the chemicals that cause your transformation. You gain one of the following features, based on the transformation you chose for your Wrathful Transformation.

Regenerative. While you are raging, you regain hit points equal to your Barbarian level at the end of each of your turns. Additionally, if any of your body parts (except for your head), are severed, they will regenerate fully by the time you end your rage. You become immune to necrotic damage while raging, and immune to poison and disease while not raging.

Animalistic. If you take the attack action while raging, you may make an attack with your mutations as a bonus action. See Wrathful Transformation for the damage dice. You also gain advantage on Perception and Survival checks relying on hearing or smell even when not raging.

Frightful. While you are raging, you are immune to the charmed condition, and hitting a creature that is frightened of you with a melee attack will cause them to take an extra 1d10 psychic damage. Hitting a creature that is not frightened of you will force that creature to make a Charisma saving throw (see Wrathful Transformation for the DC), become frightened of you on a failure.