Flammability of oil

Hi there!

I would like to know if lamp oil can be flammable enough to produce flame if you apply a magical spark to it. The idea would be to throw the oil and ignite it while flying.

More than trying to overcome magic resistance, what I am trying to do is create something that looks like a firebreathing mechanical dragon using mundane materials. I prefer him having a limit like "must drink oil to use the fire breath" than a plain ol' "he throws flames just because". the intensity does not need to be massive (a +5 to damage would be more than enough)

This can be done with naphtha, but getting hold of naphtha is somewhat more complicated outside the Byzantine area of influence :slight_smile:

So, does oil ignite with a spark? And refined lamp oil, for example?
Can the oil be ignited while being shot from the mechanical dragon's mouth and keep burning until it hits the target?

If this does not work, any other (preferably natural) substances that could be used? Tar maybe? High grade alcohol (no idea if alcoholic spirits existed in period)?


Well, lamp oil can cover a lot of things, particularly in the Middle Ages (fish oil, animal fat, various vegetable oils, ...)

But generally speaking, no, oil does not ignite just because you throw a spark at it, not unless it has been warmed beforehand and the vapors allowed to collect (and certainly, any oil that did ignite that easily would not be used in a lamp, it would just be too dangerous to have around). It is the vapors that ignite, not the liquid itself, so you need to apply enough heat to first vaporise some of it, then ignite that. A small fireball might work. Or a hot enough pilot light in the dragon's mouth.

Your best bet for an easily ignitable liquid might be distilled alcohol, but it does not burn very hot. If you arrange for your 'dragon' to spit it in small droplets, that will ignite very well. Not very damaging, but probably enough for that +5 damage you want. Or maybe you can mix alcohol and oil so the one ignites the other. Yes, distilled spirits were available in the Middle Ages :slight_smile:

Hmm... can a magical brass dragon become a drunkard? :stuck_out_tongue:

Spirits (alcohol) it is then :slight_smile: How common where those? Could they be obtained easily? Were they common?

Still I like the oil imagery, so I might keep it as a regular CrIg effect that has a necessary condition (oil) to work at all. No oil, no fire. It would need to penetrate in this case.


Lamp oil needs a wick or a hot enough fire to burn it. If it was volatile enough to catch from a spark it would be too dangerous for open lamps. Alcohol is more volatile but still wouldn't be reliable - if you want to light brandy for a christmas pudding you need to heat it first. It also doesn't burn very hot. I'm at a bit of a loss for suitable volatile liquids that can be made without fractional distillation which is somewhat post medieval - maybe turpentine which is extracted from pine resin.
A better route may be self heating mixtures - oil of vitriol (anhydrous sulphuric acid) plus an oil water emulsion will get very hot - it may not even need a spark. Other options are quicklime + water or iron filings + strong acid. The last generates hydrogen which will definitely catch from a spark.

Edit: Halancar is quite right that a fine spray makes things easier, however a more solid stream carries further. Two nozzles may be in order.

What about Whale oil?

Some of these statements about lamp oil seem very off (or just over-generalized) to me. Let me take three different example to explain it: paint, pollen, and alchohol. If you have a puddle of spray paint, it is not particularly dangerous to have fire near it. Yet if it has been sprayed (which makes it colder, not warmer), holding a small flame in the spray creates a flamethrower. In the case of pollen, there's really no more worry about it burning when collected on the ground than about everything else on the ground. Yet if you take a handful of pollen and toss it in the air you can get a nice fireball with just a little flame. Similarly, while many high-proof alchohols will certainly light, spraying the same alchohol out of your mouth can allow you to create a nice puff of fire. I'm not saying a single spark is enough, but you really only need a minimal source of fire in these cases. More care needs to be put into comparisons between flammability of liquids and the flammability of aerosols of the same substance.

So, while splashing the liquid might not work well, spraying it might create exactly the effect you're after. This won't leave the victim soaking in burning liquid, but it didn't seem like you cared about that type of damage. Since you're just looking at +5 damage, an aerosol of a relatively common product should do just fine for you. I don't have the same experience with lamp oil as I do with my earlier examples, but I suspect a lamp oil aerosol would burn very nicely.


Ok, lets take advantage of your exalted collective brains :slight_smile:

I have a snake-like dragon. he has a piston bellows in his stomach, that he uses for several functions. one of those functions is spraying the guy in front of him with a nice and warm flame causing +5 damage at voice range.

Let's see if you agree to this. I have 2 versions of this:

    R: Voice, D: Mom, T: Ind
    12/day, +12 penetration
    The jet of flame that the small dragon can shot causes +5 damage. He can decide to spend 3 charges, and shot a more concentrated shot that causes +10 damage.
    This effect is resisted as usual
    B4 (+5 dam), +2 voice, +2 flexibility; 12 uses/day +4, Penetration 12 +6

    Re(cr)Aq(Ig) 34
    R: "Voice", D: Mom, T: Ind
    12/day, aimed
    The jet of flame is caused by the ignition of the sprayed oil using a small silex spark in the dragon's mouth. The spray causes +10 damage, with a decreasing -1 per pace range. This damage can be increased to damage +15, with the same -1 per extra pace spending 3 charges of oil.

  • This effect is Aimed, but ignores MR. The aiming range is short, so it should be easy to hit.
  • Necessary Condition: Requires the consumption of oil to work
    B5 (control a liquid in a violent way) +2 "voice" (10 paces effective range, but more than touch), +1 requisites., +2 flexibility; +4 12 uses/day.

the first version is 100% by the rules, so there is no problem with it at all. The oil is cosmetic there, but I think it should be there. I am less sure about the second version. I prefer it because then the oil is an integral part of the effect, and sounds much more feasible using mechanica of heron :slight_smile: but I doubt if this is possible.

Kosher or not?

Thx :slight_smile:

For what you described, I like the second version. I think it should be Re(Cr)Aq(Ig), but still only +1 for requisites, including the Creo requisite because it's like having a tiny torch lit inside of it. I'm not so sure about the increase to +15, though.


Forgot the +2 magnuitudes because of the flexibility. That raises the effect to a whooping level 34!! True about the Creo thing. Adding both changes now :slight_smile:

You could have the CrIg as a separate effect to just fill it's mouth with sparks - have flints set in the roof of the mouth and an iron tongue tip. Then it's a much simpler ReAq to spray whatever is in the reservoir - unless it would be even easier to have ReTe work the pump and have the spray be truly mechanical.

If the spray aperture dilates during the action you could have a spray (for ease of ignition) that turns into a stream (for range and concentration of heat) :mrgreen:

arc of fiery ribbons as an alternative?

The separate ignem effect is quite easy to do. Then it ends up like this.

Breath of the Dragonkin ReAq34
Can shot a spray or a concentrated jet of whatever liquid is in his reservoir. The liquid generally is oil, that can be ignited using the ignem effect. The spray effect is akin to a +5 damage arc of fiery ribbons, while the jet is up to +10 damage. The effect needs to be aimed.
Base5, +2Voice, +3 flexibility (individual +15 damage concentrated shot if ignited vs +5 spray "ribbons effect"); 12 uses/day +4

If I remove the flexibility, it comes down to a level 19 effect. The level of damage (+10 or +15 is made on the fly). Probably +10 would be more accurate here for the intense flames.

Bite of the Salamander CrIg10
A flint and metal combination in the drake's mouth. It ignites anything that the Anima bites. It can also ignite the liquid as it passes through its mouth, causing it to cause damage when it hits the target. Belcher also likes to bite logs in a fireplace. Or the chair where Igneus is sitting :mrgreen:
Base 4 (ignite something flammable, up to dry wood), +1 touch, 24 uses/day +5

The flexibility of the Breath is again high, since I have had to increase the flexibility to increase the effect for the ribbons.


why ignite the oil (or whatever) with sparks or a flame. Why not just heat the liquid itself until it burns? I'am not sure about the arts used for this (don't have the guidelines at hand).


The form would be CrIg and if we were doing this Hermetically then heating the oil to ignition point would just be a cosmetic variant on the mouth full of sparks, less a magnitude if it can only affect oil. However, the rule with Mechanica seems to be that effects must be achieved with almost plausible mechanisms that could be invented with medieval + classical (?+ arabic) technical knowhow. With that limit, how do we generate that sort of heat without flame. The oil of vitriol + buttered brandy reaction might serve even without using magic to fake it but would you really want a somewhat silly drake drinking and spraying extra strong sulphuric acid?


I don't see this as completly cosmetic. As sparks have to be targeted and the oil must be long enough in contact with the sparks to ignite. With the oil as target you don't have this problem. But yes, this option would be more obviouse magical and less spectacular.



Heating the oil would be ignem as well, so the result is similar in the end. From a visual point of view, the drake will be expelling a torrent of flames (even if oil-scented) through its mouth, so the end result is pretty much the same. Having the foire-creating effect be separate has the advantage that he can set things on fire by biting them as well, without having to spend part of his flamethrower abilities. :slight_smile: As you can see he can ignite stuff 24 times per day while he can only throw flames 12 times per day. The difference is voluntary. And also because I cannot make myself believe that his -3 size body could contain enough oil for 24 shots per day.

Heating the oil with ignem wouldn't be just a cosmetic effect. As someone who spends a lot of time in the kitchen I can tell you that hot oil ignites much better then cold oil. Any fuel burns better the closer in temperature it is to it's kindling point. Thats one of the reasons why grease fires in the kitchen are so bad. Of course the other reason is that it's very easy to aerosolize very hot oil by adding water or alcohol to it. (Which cooks do all the time) The instant steam carries the hot oil particles into the air and if there is an open flame nearby WOOMF!!!

I think his point is that heating the oil to burn = heating the oil to burn. Thus the difference between igniting the oil with CrIg appearing as a bunch of sparks and igniting the oil with CrIg appearing as a flame is purely a cosmetic one when determining the magnitude of the spell. Either way you have the same CrIg effect. So whether this CrIg effect appears as a bunch of sparks or appears as a flame is cosmetic.


I think the sparks is a nice way to do it. Use ReAq to spray the oil (as a cloud of minute droplets much like a flame blower) from the back of the mouth and have it ignited by the sparks running between the lower and upper teeth. Then you get two low effects to instill. One ReAq "blow a cloud of oil" and a CrIg "make warm sparks between the teeth".

If you make the sparks environment triggered on "when something sprays forward from the mouth" it would look like smoke bellows forth and then ignites in a fireball.

Don't have the books to do the levels, but for a cloud of lamp oil (you could keep it warm by having a warming effect on the cannister, if you wish) +5 damage from the sparks should ignite it well. After all flame blowers use small torches to do the same.

That was my idea as well after reading you all. I am going for base 4 "ignite something flamable like dry wood" for the mouth effect. This means that it can ignite the oil easily, or bite a chair and ignite the chair as well :mrgreen: Since it is 2 effects, it wins in flexibility, even if that means +1 season in the lab!

After reading TSE I think I might be going overboard with making this credible. In TSE there is stuff like transparent iron, flying chariots and CrAu vessels "just because", without any kind of explanation how the mechanica/anima achives that effect. I still prefer this quasi-scientific approach, though :slight_smile:


Finally I am going for those 2 combine effects.

Spite of the Fiery Asp (ReAq19)
R: Voice D: Instant T: Ind
The anima has a liquid reservoir in its stomach. The liquid can be propelled forward through its mouth using the hydraulic pump that fuels most of the Anima's powers. While there is oil or another liquid in its reservoir, the Anima can shot a jet of whatever liquid is in his reservoir through its mouth. The liquid generally is oil, that can be ignited using the Bite of the Salamander effect. If the oil is ignited, it does +10 damage, with a -1 to the damage for each pace between the Anima and he target. The effect needs to be aimed, but bypasses magic resistance. Oil is the most common fuel, but the Anima has also been known to use reagents like Naphtha, or venom sometimes.
Base5 "throw liquid violently", +2Voice; 12 uses/day +4

Bite of the Salamander CrIg10
A flint and metal combination in the Anima's mouth. By soaking its teeth in oil and striking the flintstones together, the Anima can ignite anything that it bites. It can also ignite liquid as it passes through its mouth, causing it to cause flaming damage when it hits the target. Belcher also likes to bite logs in a fireplace. Or the chair where Igneus is sitting :mrgreen:
Base 4 (ignite something flammable, up to dry wood), +1 touch, 24 uses/day +5