Steam Engine Rules for 3.5e/Pathfinder

[tankhedgehog]

Hello all, I am playing a solo game (Mythic GME) of 3.5 (with some pathfinder 1e thrown in) and my character's been working on trying to build himself an airship. I've got lift mostly sorted (a bunch of levitate spells) but for propulsion I'd like to create some nice steam-engine propellers. Now, as this is a solo game, I could obviously grant myself whatever I wanted, but there's no fun in that, so I've been playing with the rule that anything is allowed as long as it's official WotC or Paizo content (unless it's, like, really really cool 3rd party stuff).

This brings me to my question: Are there any official rules for steam engines in 3.5/pathfinder 1e? If there's nothing official, then does anyone have any recommendations for very solidly built 3rd party rules for them?

Thanks in advance

[Fizban]

Arms and Equipment Guide has stats for zeppelins and dirigibles with "animated propellers," which apparently don't require any magical creation by default, and speeds which seemed reasonable enough for steam propulsion when I researched it, and they're my first go-to. But as for literal steam engine rules, I'm pretty sure there aren't any in 1st party 3.x. I have run the numbers and found that medium fire elementals should indeed be sufficient to run a boiler, but that's just fuel hacks (and custom cubed Wall of Fire items are way better).

For 3rd party, Sorcery and Steam has some nice stuff. I mostly recommend it for having the best black powder firearm rules, but they've also got a section of fantasy steam vehicles, including a cool steambike and the expected zeppelin. Their vehicle stats don't use the ship section system of AaEG/Stormwrack/other 1st party, but could be converted or used as-is (they also use a much more active drive skill). You can get the pdf on drivethrurpg for $5.

That's not the only one of course, there's also Dragonmech and Iron Kingdoms and probably at least a few more I've never taken note of, but for your purposes I'd say those are overkill. Dragonmech is about giant (up to city sized) mecha, and includes a class with loosely defined and thus hard to use/abusable "steam powers," while Iron Kingdoms is more focused on its magitech reskin but also has steam powered mecha. Neither gives particularly useful "just buy X size steam engine to power Y thing" stats.

There's also the Warcraft books, but those aren't easily available, and are possibly even less useful. They have a technological device "system," which is more of a suggestion than a system, but lots of example items (which if reverse engineered won't match the given rules). I mostly bring them up because Warcraft is a very visible franchise that has steam tech and tabletop books, but they're not too useful for anything other than a Warcraft style game.

[tankhedgehog]

Arms and Equipment Guide has stats for zeppelins and dirigibles with "animated propellers," which apparently don't require any magical creation by default, and speeds which seemed reasonable enough for steam propulsion when I researched it, and they're my first go-to. But as for literal steam engine rules, I'm pretty sure there aren't any in 1st party 3.x. I have run the numbers and found that medium fire elementals should indeed be sufficient to run a boiler, but that's just fuel hacks (and custom cubed Wall of Fire items are way better).

For 3rd party, Sorcery and Steam has some nice stuff. I mostly recommend it for having the best black powder firearm rules, but they've also got a section of fantasy steam vehicles, including a cool steambike and the expected zeppelin. Their vehicle stats don't use the ship section system of AaEG/Stormwrack/other 1st party, but could be converted or used as-is (they also use a much more active drive skill). You can get the pdf on drivethrurpg for $5.

That's not the only one of course, there's also Dragonmech and Iron Kingdoms and probably at least a few more I've never taken note of, but for your purposes I'd say those are overkill. Dragonmech is about giant (up to city sized) mecha, and includes a class with loosely defined and thus hard to use/abusable "steam powers," while Iron Kingdoms is more focused on its magitech reskin but also has steam powered mecha. Neither gives particularly useful "just buy X size steam engine to power Y thing" stats.

There's also the Warcraft books, but those aren't easily available, and are possibly even less useful. They have a technological device "system," which is more of a suggestion than a system, but lots of example items (which if reverse engineered won't match the given rules). I mostly bring them up because Warcraft is a very visible franchise that has steam tech and tabletop books, but they're not too useful for anything other than a Warcraft style game.

Thanks for your reply! I cracked the Arms and Equipment Guide open (read brought up the pdf) and gave it a look. I found the stats for zeppelins and dirigibles but it seems like there isn't any information about how much thrust the propellers provide, which I kinda need since I'm trying to build an airship from scratch.

In an ideal world, I'd love something like a series of engine stat blocks with how much they weigh, what it takes to operate them (coal and water per hour) and how much weight they can move and at what speed. The best case would be a completely mundane steam engine as not only would that not have any problem functioning through an antimagic field, it would also fulfill the fantasy of a wonderful black-smoke belching airship. In my opinion the more gears it has and the more pitch black smoke it dumps into the atmosphere the better. However, if that ends up proving too difficult, settling for a magic powered engine isn't too bad.

With that in mind, how well can the rules in Sorcery and Steam, Dragonmech, and Iron Kingdoms provide something like this? As it turns out, I already own both Dragonmech and Iron Kingdoms but I haven't had the chance to read through them yet (Collecting rpg rulebooks and supplements is a bit of a hobby of mine).

[Fizban]

Well again, the thing about all of these systems is that they're designed to never actually do that. The steamtech is always a part of some other mechanic. Most provide some rate of coal and/or water consumption, sometimes including a price for said coal (which isn't priced in base 3.5), but the engine is part of something else and any measure of work would have to be reverse-engineered (and would make about as much sense as you'd expect for fantasy steamtech).

The only one that has something close to a standalone engine is Dragonmech, but those are via the dedicated base Coglayer class. It has a list of powers that you can attach/build into things, but even then a plain engine is conspicuously absent. The most it has is either the automator, which automates a short process (weight based on the thing being animated), or the rotor arm, which has a lifting weight if you use it for a helicoptor rotor but nothing else. And as class features they require someone with the class to keep them working (as written you can easily game the system, but some maintenance is still required).

Iron Kingdoms subsumes the cost and effects into the chassis of steamjacks or steam armor. Sorcery and Steam does the same with their armor and vehicles, but at least they have an array of basic steam vehicles to choose from. Warcraft dismisses the overhead almost entirely, with "technological devices" working first and having description of steam or other tech later- if you applied their system you'd essentially be doing the same thing you would to make any other vehicle, but the DM would be likely to let you count it easier to make than "normal" airships by not having to produce the lift (and you'd still need to be a Warcraft Tinker to build it).

The best option really is to just do the research yourself if you want it on that level of detail. Look through Wikipedia until you find an airship that matches what you want. Now you've got engine specs and some idea of how long it took how many people to design the thing, and build the thing (I found the Giffard_Dirigible (https://en.wikipedia.org/wiki/Giffard_dirigible) appropriate). Assuming your setting even has enough technology level to consider seriously using steam, you can ad hoc that into some DCs and skill checks (based on their skill values), or just abstract it away by spending an appropriate amount of time or something. Note that while technology advanced rather quickly once we started mass producing steel, it did still take decades (the Giffard has a 3hp steam engine, but while the earliest steam engines produce that much power in 1712, they were 1/4 as efficient until a breakthrough from a different inventor in 1778, and it took 5 more years after that to have them turning wheels properly). Unless your character already has readable blueprints to work from (in which case your DM might just let you Fabricate it), trying to take the player's idea of "hey I'll make a steam engine" and turn it into something useful should take similarly long in-character, at least several years unless you can use Fabricate to eliminate all actual production times (presumably as an adventurer you have sufficient funds to spend all your time inventing and no limit on raw materials, unlike most people).


As for existing ship stats- well clearly their motive force provides sufficient thrust to move the given ship at up to the the given speed through the standard medium. AaEG's airships are categorized as wind-driven, the same as sailing ships, so their propellers aren't providing main thrust- just enough to turn the ship and act in place of a rudder (speed comparable to the Giffard). Even if you had thrust values (which would actually be a derived value based on the propeller system driven by the steam engine, which are usually rated in units like horsepower or watts), you'd still need to model the airship itself, moving through the air, to figure out what that actually turns into. Unless you happen to be an aircraft engineer of some sort (which you could be, granted), you probably don't have access to the software and technical skills to do that.

Further, even if you do use a realistic steam engine, you may find realistic fuel consumption is rather use-prohibitive. Even assuming you've got a source for that much fuel, you've still got to carry it, and the engine. Tons of fuel, tons of water, tons of engine, tons of ship. Levitate and even Shining South's Suspension spell really aren't actually up to the task of carrying a Ship, especially not with any cargo of note (also- if you're using magic to lift it, a non-magical engine is the least of your worries regarding Antimagic Field).

In short, the easiest way to make an airship in dnd is to use pre-existing airship stats, because they're based on the writer's fiat decision of how much it should cost and do (the same way spells are), rather than derived from spells that are meant to do other things. It turns out when they decided to be conservative about normal spell effects to prevent this sort of thing, they did manage it pretty well. The best case scenario is combining a single/few-room floating "stronghold" from Stronghold Builder's Guide (no weight limits) with a Fabricated steam engine blueprint (from an alternate material plane or Wish or something) and a custom cubed Wall of Fire item (and Create Water item). With a free Wish from a genie that could get in the air for as low as like 10,000gp, actually beating dedicated airship stats.

If what you specifically want is a black-smoke belching non-magical airship, Warcraft would be the most appropriate, and the cheapest. But they still require a dedicated class to build stuff, with a good few levels for that tech rating.

[stack]

Ships of Skybourne (https://www.drivethrurpg.com/product/171127/Ships-of-Skybourne)has airship rules, including various power sources. Wood, oil, and alchemical engines could be considered steam powered. I believe there was a 3.5-era 3pp book that it was at least partly based on, but I don't know the title.

[tankhedgehog]

Ships of Skybourne has airship rules, including various power sources. Wood, oil, and alchemical engines could be considered steam powered. I believe there was a 3.5-era 3pp book that it was at least partly based on, but I don't know the title.

I actually just bought Ships of Skybourne yesterday (before I saw your post) and having finished reading it today, it is basically exactly what I was looking for. It has two types of steam engines and detailed rules for building your own airship, including figuring out how fast it can move, its hit points, and all that jazz.

The only issue I have with the rules is that I can't seem to find anywhere in the book where it explains how to go from airship weight (basically just hardpoints x 2) into actual weight in tons. With the way the rules are set up, you don't ever need to know the ships weight in tons, but since I want to float my ship with a bunch of suspension-casting spell clocks, this is an important number. If nobody else knows the answer to this either, than I'll probably just use Airship weight = weight in tons

[Fizban]

Ah, I was hoping someone with some extended Pathfinder knowledge would weigh in- I only dip into PF when I hear something particularly interesting, but it seems I'll have to check out those Skybourne books too.

How many hardpoints/airship weight do various ships have? Weight is another thing that should be fairly easy to look up: a quick wiki-ing seems to say that the capacity of a caravel (the PHB sailing ship) should be 50-60 tons with a displacement (the weight of the ship) of 50-75 tons. Though Stormwrack gives a cargo of 120 tons, suggesting that their three mast caravel might actually count as a carrack.

[tankhedgehog]

Ah, I was hoping someone with some extended Pathfinder knowledge would weigh in- I only dip into PF when I hear something particularly interesting, but it seems I'll have to check out those Skybourne books too.

How many hardpoints/airship weight do various ships have? Weight is another thing that should be fairly easy to look up: a quick wiki-ing seems to say that the capacity of a caravel (the PHB sailing ship) should be 50-60 tons with a displacement (the weight of the ship) of 50-75 tons. Though Stormwrack gives a cargo of 120 tons, suggesting that their three mast caravel might actually count as a carrack.

Each hardpoint (the 10x10x10 building blocks of your vehicle) can hold a maximum of 10 tons of weight, but that's just the maximum (And if i remember correctly, only if it's designated as a cargo hold). There are rules for vehicle encumbrance that reduce the speed and maneuverability of the vehicle as it gets weighed down. I think something like less than or equal to 2 tons per hardpoint is considered a light load that has no effect on the ship and it goes up from there.

Having played around with the ship design rules, I can say that they make some good sense and I like them quite a bit. i'm quite satisfied with my airship. My only complaint would be that it moves a bit slower than I'd like, but I suppose that's what I get for stubbornly sticking with steam engines (as opposed to the fancier options like necromantic or shadow) while simultaneously designing the outside of the airship entirely out of adamantine, which, as it turns out, makes it kinda heavy >_>

[Palanan]

Originally Posted by tankhedgehog
…while simultaneously designing the outside of the airship entirely out of adamantine….

That’s not an airship, that’s the thing the Underminer was driving.

:smalltongue: