You have a walking speed of 30.

Being a Construct, you don't really age. Yes, rust and disrepair are a thing, but you don't age. You could theoretically live forever, if you're kept well. Some Ancient Gear Golems are thousands of years old, while others are freshly minted every day.

While Ancient Gear Golems come in many sizes and appearances depending on their frames, yours happens to be between 4 and 7 feet tall, making you Medium.

The Ancient Gears have taken over many a city, many a race. You know Common, with which to speak to all; Terran, with which to speak to your fellow constructed kin; and another language, likely one from a civilization you took part in conquering, or that found and repaired you.

You are not living. You are not human. You have no soul. But you do have some little bit of personage in you. You are a Construct.

Somewhere deep down inside, there is a single cog inside you made with antimagic. While it may seem odd, even fantastical, it is standard for ever Ancient Gear machine. When you make a weapon attack, ranged or melee, the creature you are attacking cannot make a reaction. When taking the Dash, Dodge, or Disengage action, you also cannot be targeted for opportunity attacks.

Due to you being made of plate metal, stone, and many many gears, you don't need armor to be armored. This doesn't mean you can't wear armor, but it won't give you much extra protection. While you are wearing no armor, your AC is equal to 13 plus your CON modifier, but you have disadvantage on Stealth checks, as your whirring motors and stomping feet make quite the racket.

NOTE: Due to complications with the Homebrew settings, you're going to have to change your AC yourself. This overrides Barbarian and Monk's Unarmored Defense if it is higher.

Due to not being organic, you cannot become sick. You also have advantage against being Poisoned, and resistance against Poison damage.

All Ancient Gears are built on a frame. They are used for different things, because if there's one thing the Ancient Gears know, it's that there's a place for everything and everything must be in place.

Soldier Frame:

You're built for battle. A standard Ancient Gear frame, used for Soldiers and Engineers and the like. Big, tall, masculine, and broad, they're meant to be intimidating, unrelenting stormtroopers. You gain +1 to Strength, +1 to Dexterity, and +1 to Constitution. You also gain proficiency with one skill and two weapons of your choice.

Gadget Frame

You're built for collaboration. The Gadgets, while not part of the Ancient Gears originally, have given over some tech, and you're based on that. You're smaller and, dare I say, a little cute. Gadgets are shyer, quieter, and better at tasks that require more finesse. You gain a +2 to Constitution, and +1 to either Charisma or Intelligence, proficiency with one skill of your choice, and either Guidance or Mending. You cannot use Mending on yourself.

Scrap Frame

The Scrap are monsters made out of literal discarded junk, and you're no different. You're a vaguely humanoid collection of gears and old machines, mildly frightening and horrifyingly effective. Scrap monsters don't care about anything but upgrades. They are ruthless killers, even dismantling their own kind just to add to themselves. You gain a +2 to Constitution, a +1 to Strength, and can collect Scrap. During a Short or Long rest, you can expend 5 lbs. of Scrap to roll an extra hit die. If you do this during a Long Rest, you gain Temp HP equal to that amount.

Megaton Frame

You're built to destroy. You're big. BIG. A true golem. You are an impenetrable wall and have an unstoppable fist. You care not about the ants beneath your feet. You stomp forward, no matter what. You gain +2 to Strength and +1 to Constitution, and you cannot be slowed by Difficult Terrain. You also have Advantage on Strength checks; your melee attacks have advantage against objects, and objects and enemies made of stone, wood, or metal take extra damage from your melee attacks equal to your proficiency bonus.