Increase one ability score by 2 and one ability score by 1

Exochrons counter their frail forms with a continually upgraded exoskeleton, which dramatically extends their lives. If circumstances allow, they can live past 500 years.

 Exochrons are known for pursuing their passions, often with little regard for customs and laws. They tend towards chaotic, though some find discipline and a clear delineation of rules helpful in their pursuits.

 Exochrons are medium humanoids, range from 5 to 6 feet tall. Their build can be wide ranging, varying from a slender to extremely heavy duty exoskeleton depending on the class pursued.

Your base walking speed is 30 feet.

You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. You can’t discern color in darkness, only shades of gray.

You have proficiency in smith’s tools, tinker’s tools, and one other tool proficiency of your choice.

Your hit point maximum is reduced by an amount equal to twice your level.

 Exochrons do not sleep. Instead they spend 4 hours a day focused on modifying their organic form to better fit their exoskeleton and enhancing their exoskeleton to better fit their organic form. After spending time in this way, you gain the same benefit a human would from 8 hours of sleep. 

You can read, speak, and write Common. You can also speak Deep Speech.

 You can enhance your exoskeleton’s capabilities by installing one: of each specialized class module: 

• Biometric Feedback Regulator. You can spend 150 gp and 8 hours of work to permanently install this module, which supports a 1st level specialization.

• Organic Symbiosis Enhancer. You can spend 450 gp and 24 hours of work to permanently install this module, which can support a 3rd level or lower specialization.

• Biomechanical Neural Interface. You can spend 750 gp and 40 hours of work to permanently install this module, which can support a 5th level or lower specialization.

In order to activate a specialization, you must be at least that level in the class. When you complete a long rest, choose a specialization available to you for each unlocked module, if any. A specific specialization can’t be active in more than one module.

Barbarian Specializations

1st Level. When you are conscious and your rage would end, you are able to choose to extend it one additional turn instead.

3rd Level. You gain temporary hit points equal to your proficiency bonus at the end of your turn while you are raging.

5th Level. When you are raging, a creature that touches you or hits you with a melee attack while within 5 feet of you takes 1d10 fire damage.

Bard Specializations

1st Level. When a creature rolls a 1 on your Bardic Inspiration die, it rerolls the die and must use the new roll, even if the new roll is a 1.

3rd Level. When you fail an ability check with which you have expertise, and your failure is less than your proficiency bonus away from success, you may immediately reattempt the check once with disadvantage.

5th Level. When a creature uses your Bardic Inspiration, it additionally gains temporary hit points equal to the number rolled.

Cleric Specializations

1st Level. When you cast a spell from your domain spell list, roll a d100 and add your Wisdom (Religion) modifier. If the total is equal to or greater than 100, your deity intervenes and the spell slot is not spent.

3rd Level. When you use your channel divinity, you gain temporary hit points equal to your cleric level.

5th Level. As a bonus action, you can choose to deal radiant damage equal to your Wisdom modifier to undead creatures you have turned. This damage does not end the turned effect.

Druid Specializations

1st Level. You gain proficiency in Nature. If you already have proficiency, you instead gain expertise.

3rd Level. Your exosekelton develops a rough, bark-like appearance, and your AC can’t be less than 15, regardless of what kind of armor you are wearing.

5th Level. When your wild shape ends, if your form is at its maximum hit points, you gain an extra use of your wild shape feature.

Fighter Specializations

1st Level. When you use your second wind, you can add 2 x your Constitution modifier to the amount of hit points regained.

3rd Level. When you use action surge, your exoskeleton flares to life and grants you a +1 bonus to AC and saving throws until the beginning of your next turn.

5th Level. When you use your second wind, any excess hit points you regain past your maximum become temporary hit points.

Monk Specializations

1st Level. While you are not wearing armor or wielding a shield, your speed increases by 5 feet.

3rd Level. When you score a critical hit with an unarmed strike, add your Wisdom modifier to the damage.

5th Level. When you jump, the distance you cover increases by a number of feet equal to your Wisdom modifier.

Paladin Specializations

1st Level. Aura of Renewal. When a creature within 5 feet of you regains hit points, if you have any healing power remaining in your lay on hands pool, the creature also gains temporary hit points equal to your Charisma modifier (minimum of 1).

3rd Level. Your divine sense now also identifies aberrations and monstrosities.

5th Level. The range of your auras increases by 5 feet.

Psionic Specializations

1st Level. You learn one amplification for which you meet the prerequisites.

3rd Level. If a creature in a contested check for one of your psi abilities rolls a 1 on the d20, you can choose to deal psychic damage to it equal to your Intelligence modifier.

5th Level. While you have 1 or more psi points remaining, you have resistance to psychic damage.

Ranger Specializations

1st Level. You gain proficiency in survival. If you already have proficiency, you instead gain expertise.

3rd Level. You gain blindsight out to a range of 5 feet. This increases to 15 feet while in natural terrain.

5th Level. If you reduce one or more creatures to 0 hit points, you gain a bonus to your damage rolls against those creatures equal to your proficiency bonus for the rest of the day.

Rogue Specializations

1st Level. If you move half your speed or less on your turn, your exoskeleton muffles your footsteps, making you inaudible.

3rd Level. The Search action is now one of your options for cunning action.

5th Level. Your sneak attack deals an additional 1d6 damage.

Sorcerer Specializations

1st Level. You learn one metamagic option.

3rd Level. When you score a critical hit with one of your spells, you can choose to teleport up to 10 feet to an unoccupied space you can see.

5th Level. Once per turn when you roll damage for a cantrip and roll the lowest number possible on any of the dice, choose one of those dice, roll it again and add that roll to the damage.

Summoner Specializations

1st Level. You learn one force augment for which you meet the prerequisites.

3rd Level. You have expertise when making an Intelligence (Investigation) check to learn a new summoning formula.

5th Level. You add your proficiency bonus when rolling on the Convergence Table. Any total above 100 is treated as 100.

Warlock Specializations

1st Level. You learn one eldritch invocation for which you meet the prerequisites.

3rd Level. After casting a Warlock spell of 1st level or higher, gain a bonus to your next damage roll equal to your Charisma modifier (minimum of 1).

5th Level. When you have to make a death saving throw at the start of your turn, an ethereal hand, tentacle, or other appendage befitting your patron appears and plunges directly into your exoskeleton, tapping directly taps into your spirit. You no longer die when you fail three death saves, but instead gain one level of exhaustion for every failure above 2.

Wizard Specializations

1st Level. You automatically identify a spell as it’s being cast within 60 feet of you if you already know it.

3rd Level. You are able to prepare a number of additional spells per day equal to your proficiency bonus.

5th Level. When you use arcane recovery, you can choose to recover Hit Dice instead of spell slots, or a combination of both resources. The number of Hit Dice plus combined level of spell slots must be equal to or less than half your wizard level (rounded up), and none of the slots can be 6th level or higher.