Homebrew rules for robots as a playable race option in Dungeons & Dragons 5e, heavily influenced by the droids from Star Wars. In play, assume that a player character robot has the same free will as other characters, lacking any specific inhibitor programming controlling its behavior (e.g. no built-in Asimov’s Laws).
ROBOT
Ability Score Increase. Your Constitution score increases by 2.
Age. Unlike living beings, robots might be of any age, from a few months to hundreds of years. Age has no effect on ability scores or other characteristics.
Creature Type. You are a Construct.
Size. You are either Small or Medium (your choice).
Speed. Your base walking speed is 30 feet if built as a humanoid on two legs. At your choice, your robot may be created with more than two legs or treads, instead having a base speed of 25 and gaining advantage on Strength saving throws and ability checks made against forced movement such as being grappled, shoved, pushed or pulled by a spell.
Electrical Systems. You gain vulnerability to lightning damage.
Immutable Form. You are immune to any spell or effect that would alter your form.
Machine Anatomy. You don’t require air, food, drink, or sleep. You are also immune to poison damage and the poisoned condition.
Recharge. A robotic creature recovers all expended hit dice and restores to full hit points in functionality after a long rest.
Repair Only. You cannot recover hit points from magical healing or rests, but a Mending cantrip can restore 2d4+2 hit points to you once between your short rests. A character proficient with Tinker’s Tools, including yourself, can work on your body during a short rest and allow you to spend hit dice to recover lost hit points.
Models (i.e. subraces)…
PROTOCOL AND ETIQUETTE
Ability Score Increase. Your Charisma score increases by 1.
Specialization. You gain proficiency in your choice of Animal Handling, History, Investigation, Medicine, Nature or Performance.
A Million Forms Of Communication. You may use the Comprehend Languages spell at will. At 5th level, you may use the Tongues spell on yourself at will.
UTILITY AND REPAIR
Ability Score Increase. Your Intelligence score increases by 1.
Internal Tools. You are proficient with Tinker’s Tools and have the equivalent of such tools built into your body. These tools may not be lost or stolen from you unless you are incapacitated, unconscious or dead.
Low-Light Optics. You have darkvision, allowing you to 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.
Quick Repairs. You may use the Mending cantrip so long as you have access to any sort of solid raw materials that you can repurpose and transmute (coins, metals, glass, rocks, bricks or other objects).
Technical Programming. You are proficient in your choice of any one tool or vehicle.
SECURITY AND PATROL
Ability Score Increase. Your Strength score increases by 1.
Armored Body. When you aren’t wearing armor, your AC is 13 + your Dexterity modifier. You can use your armored body to determine your AC if the armor you wear would leave you with a lower AC. A shield’s benefits apply as normal while you use your natural armor.
Intruder Alert. You gain proficiency in the Perception skill.
Low-Light Optics. You have darkvision, allowing you to 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.
Metal Fists. Your unarmed attacks hit like a club, doing 1d4 + Strength modifier bludgeoning damage and counting as having the Light property. You are proficient with such attacks.
Weapon Mounts. You may have other weapons built into your body, at usual costs to purchase or craft. These weapons may not be lost or stolen from you unless you are incapacitated, unconscious or dead.