Some prosthetics upgrades can only be used on an arm while others can only be used on a leg. A weapon hidden within a prosthetic can only be found by completing a successful DC 15 investigation check on the prosthetic. An upgrades saving throw DC is equal to your artificer spell save DC.

Hidden Melee weapon (1 upgrade slot, price: The weapons cost + 2gp): You can hide one melee weapon that lacks the reach or two handed property on this prosthetic. You can draw this weapon from this prosthetic at will without requiring an object interaction.

Hidden Reach weapon (2 upgrade slots, price: The weapons cost + 10gp): You can stow one melee weapon that has the reach or the two handed property on this prosthetic. You can draw this weapon from this prosthetic at will without requiring an object interaction.

Hidden Hand Crossbow (1 upgrade slot, price: The weapons cost + 10gp): You can draw this weapon from this prosthetic at at will without requiring an object interaction. If this limb isn't an arm, you suffer disadvantage on attack rolls with the hand crossbow.

Grappling Hook (2 upgrade slots, recharge 4-6, price: 50gp) As a bonus action or action you can use this grappling hook. Choose a point on an object you can see within 30ft of you. You move in a straight line to that point, if there is anything obstructing this movement, you instead end your movement when you reach the point that is obstructed. For every 500lbs you weigh, you need one additional prosthetic with this upgrade to be able to move with the grappling hook which you can use simultaneously as part of this action. You can also target creatures with the grappling hook instead of objects. Make a ranged weapon attack against them with the grappling hook, on a hit, they take 1d6 piercing damage and must make a Strength saving throw. On a failure you can move them up to 10ft towards you in a strait line, or you can move up to 30ft towards them in a straight line. So long as one grappling hook recharges, they all recharge.

Shield (2 upgrade slots, price: 10gp) As a bonus action or as a reaction when you are hit with an attack, you can unfold the shield stored on this limb. While the shield is unfolded you gain the purposes of the shield and cannot use any other upgrades that require 2 or more upgrade slots upon this limb. You can only have a maximum 3 shields unfolded at any given time.

Blood Siphon (1 upgrade Slot, price: 300gp) While you are at half or below your maximum hit points, whenever you expend a charge on an upgrade placed on this limb, you gain 1 additional charge to spend on the upgrade.

Arm of Dexterity (1 upgrade slot, price: 100gp + 200gp per point of dexterity higher then your own.) This arm gains its own Dexterity score. You cannot raise this arms dexterity score above 20. This arm uses the dexterity score assigned to it instead of your own for attack and damage rolls and gains proficiency with any finesse weapons and thieves tools it holds.

Flame Spitter (2 upgrade slots, recharge 4-6 price: 350gp,) As an action you can expend 1 charge to sprout a cone of fire from your flame spitter. Each creature in a 15ft cone originating from you must make a Dexterity saving throw. Taking 2d6 fire damage on a failed save. For every additional charge you expend the damage increases by 1d6, to a maximum of 6d6. They take half damage on a successful save. You can spend 10x the amount of gold on this upgrade to be able to use it as a bonus action.

Limb Krovska (2 upgrade slots, recharge 4-6, price: 350gp): As an action you can make a ranged attack with a mini force cannon. The mini force cannon has a range of 150/800ft. Expending 1 charge as part of this action causes the attack to deal 2d6 force damage. For every additional charge you expend the damage increases by 1d6, to a maximum of 6d6. You can spend 10x the amount of gold on this upgrade to be able to use it as a bonus action.

Amplifier (2 upgrade slots, recharge 4-6, price: 350gp): When making a melee attack with this prosthetic you can expend charges to deal additional damage. Expending 1 charge as part of this action causes the attack to deal 2d6 additional force damage. For every additional charge you expend the damage increases by 1d6, to a maximum of 6d6.

Leg of Springing (1 upgrade slot, price: 300gp) Your jump distance and jump height are tripled. Once per turn if you hit a creature with a weapon attack directly after jumping, they must succeed a dexterity saving throw or are knocked prone. The majority of your legs must have this upgrade to gain its effects.

Leg of Stealth (1 upgrade slot, price: 300gp) You gain proficiency with stealth checks. The majority of your legs must have this upgrade to gain its effects.

Leg of Balance (1 upgrade slot, price: 250gp) Difficult terrain does not slow your movement, and standing up only requires 5ft of movement. The majority of your legs must have this upgrade to gain its effects.

Arm of Strength (1 upgrade slot, price: 200gp, and a further 200gp per point of strength higher then your own.) This arm gains its own strength score. You cannot raise this arms strength score above 20. This arm uses the strength score assigned to it instead of your own for attack and damage rolls along with determining its carry weight. You gain proficiency with martial weapons held in this arm.

Limb of Mending (1 upgrade slot, recharge 4-6, price: 200gp) As an object interaction, you can expend charges to heal yourself or an ally within reach of this limb. Each charge you expend heals the target 1d6 hit points, to a maximum of 6d6 hit points.