This is a spin off of this thread.
So I've been working on a Steampunk game for quite a while now and I've recently been working on steam powered prosthetic limbs aka Steam Proxy. As I said above, this is posted in another thread but I wanted a little more feed back so I thought I'd just make another thread. I took the majority of the rules I'm using from this thread on the WoTC boards. I thought this might be of use to some people even if they're not running a Steampunk game because I'm sure you could just change the fluff and make Steam Proxy a magical prosthetic, maybe something like a Warforged arm. Anyway, here's what I have at the moment.
Steam Proxy is a steam-powered replacement for a lost or injured body part (arms and/or legs); it requires a high degree of knowledge about anatomy and mechanics to attach. Steam Proxy replacements are usually priced quite highly because of this fact and it is a very dangerous procedure to attach any piece. Crafting Steam Proxy requires the Craft Steam Proxy feat (see below). *Special Note: Steam Proxy is considered prohibited "armor" for Druids.*
Craft Steam Proxy – Prerequisites: Knowledge (Engineering) 5 ranks, Heal 3 ranks – You are able to Craft and attach Steam Proxy. It takes 1 day for every 1,000gp in the price to create (although it only takes 1 hour to attach). To craft Steam Proxy, you must use up raw materials costing half of its price.
Attachment: Attaching Steam Proxy to flesh and having it work is one of the hardest medical procedures most have come to see. For the technician it is incredibly difficult and for the patient it is almost unbearably painful, some cannot stand the pressure it applies to their nervous system. Attaching a piece of Steam Proxy takes only 1 hour for each individual piece (hand, glove, etc.) however recovery for the patient takes at least 1 week. During the procedure the patient must make Fortitude Saves, the DC depends on the section and the application of multiple sections requires multiple saves. On a failed save the application of the Steam Proxy fails and the procedure cannot be attempted again until the patient spends at least 1 week recovering (the technician usually charges an additional amount equal to 1/4 the original price if the application fails). However a character must roll all Saves regardless, therefore a patient getting a Steam Leg must make 3 Fortitude Saving throws (1 for the Steam Foot, 1 for the Steam Boot, and 1 for the Steam Leg), and is able to fail all 3, recovery time stacks from each failed save.
Recovery: After a successful procedure, a patient must make an additional Fortitude Save for each attachment or take a -2 penalty to Strength and Dexterity for 1 week per each failed save. Each week after the 1st the penalties lessen by -2 until the damage is completely healed.
Part – Steel/Iron – Cold Weather – Mithril – Adamantine – Fortitude Save DC
Steam Hand – 750gp – +100 – +300gp – +400gp – 12
Steam “Glove” (Forearm) – 1,250gp – +300 – +650gp – +725gp – 15
Steam Arm – 2,200gp – +600 – +975gp – +1,250gp – 18
Steam Foot – 600gp – +75 – +250gp – +350gp – 12
Steam "Boot" (Below the Knee) – 1,200gp – +250 – +525gp – +650gp – 15
Steam Leg – 2,050gp – +550 – +850gp – +1,075gp – 18
Benefits &Penalties
All: All Steam Proxy is subject to sundering as if it were a shield; normally a piece of Steam Proxy has a Hardness of 10 and 15 hp per section (i.e. a Steam Hand has 15 hp, a Steam Glove has 30 hp and a Steam Arm has 45 hp). Mithril Steam Proxy has a Hardness of 15 and Adamantine Steam Proxy has a Hardness of 20, but they both keep the same hp. All pieces give the patient a -1 penalty on Disguise checks and Stealth checks made to move silently. Steam Proxy made form Iron or Steel is subject to freezing, any character with a Iron or Steel Steam Proxy attachment must make a Fortitude Save (in addition to any saves he would normally have to make) whenever taking cold damage or take 1d4 points of Dexterity damage in addition to the cold damage. Bonuses granted by Steam Proxy pieces stack with each other (i.e. 2 Steam Hands grant a +2 on Grapple checks and CMD checks to avoid being disarmed).
Steam Hand: Steam Hands increase the patient's grip and range of movement with this hand. The patient gains a +1 bonus on all Grapple checks and CMD checks to avoid being disarmed. Furthermore he is treated as being armed even when making unarmed attacks.
Steam Glove: The Steam Glove improved on the Steam Hand, it can be used to block and deflect attacks granting the patient a +1 shield bonus to AC that stacks with that of other Steam Gloves but no other bonuses (to a maximum of +2 with 2 Steam Gloves), when enhanced they are treated as a single Shield. If an attack is made with either arm the shield bonus is lost until the next round with arm. A Steam Glove also grants the benefits of a Steam Hand.
Steam Arm: By replacing the shoulder down to the fingers, the Steam Arm increases a patient’s strength and power. The patient increases his unarmed strike damage (when punching) by 1 step (1d3 becomes 1d4, 1d4 becomes 1d6, etc), along with granting the patient use of the Power Attack feat 3/day, if the character already has Power Attack, he may add an additional +2 to damage per arm when Power Attacking 3/day. A Steam Arm also grants the benefits of a Steam Glove and Steam Hand.
Steam Foot: A Steam Foot allows you to proceed where those with bare feet would not normally be able; you halve the penalty to move through dangerous terrain (such as caltrops). Two feet enable the patient to move through these obstacles with no penalty.
Steam Boot: Having a piece built below the knee allows the patient to significantly increase their ability to leap and jump. The patient receives a +2 competence bonus per Steam Boot applied to all Climb and Acrobatics checks. A Steam Boot also grants the benefits of a Steam Foot.
Steam Leg: A Steam Leg greatly enhances the patient’s ability to run; the patient gains the Fleet feat as a bonus feat. A Steam Leg also grants the benefits of a Steam Boot and Steam Foot.
Right now I'm in the process of working on "attachments" which add additional benefits. Something like Steam Pincers would let the character grapple and still have a free hand but the Pincer wouldn't be able to hold a weapon, maybe 1 that lets you have a weapon attached to your arm or 1 that lets you hide a weapon inside the Steam Proxy, another 1 would probably get rid of the penalty to Stealth checks. On another note, I know its weird for a prosthetic limb to grant you a benefit but the reason I did it was because it has it's down sides, for instance: 1) You didn't have the money to get a more expensive attachment so someone makes you pass out from Dexterity damage. 2) Someone uses heat or chill metal on your arm. 3) Someone sunders your arm or leg, you could lose a shield bonus, extra attack, 2 handed attack, or you movement speed might be halved. 4) Rust Monsters can now eat you.
Thinking about this a little more, I'm going to get rid of the Steam Arm's power attack 3/day and change it to something that gives the character a +2 or so bonus on damage 3/day. This way it makes it a little less confusing. Also I realized I wasn't clear on this but I'm going to add it, the unarmed strike increase doesn't happen twice if you have 2 Steam Arms. So if a 5th level Monk had 2 Steam Arms his Unarmed Strike damage would only go up to 1d10 not 1d12.
EDIT: So this is what the Steam Arm looks like now. Steam Arm: By replacing the shoulder down to the fingers, the Steam Arm increases a patient’s strength and power. A patient with a Steam Arm may add +2 damage per arm to any melee attack 1/day/Steam Arm, in addition, the patient increases his unarmed strike damage (when punching) by 1 step (1d3 becomes 1d4, 1d4 becomes 1d6, etc), this unarmed strike damage does not stack if the character has 2 Steam Arms. A Steam Arm also grants the benefits of a Steam Glove and Steam Hand.