I've got a party heading toward an encounter in a dense forest, and one of the party members has recently stocked up on alchemist's fire ...so in the eventuality that one of his attacks misses and hits the grass I'm trying to figure out how long they'll have until a little splash becomes a true forest fire.
The SRD covers the speed of a moving forest fire, but not how long one takes to get going.
I'll be glad for any advice you folks can offer.
I imagine it would spread quickly, although I thankfully have no real experience with forest fires. I think that it might take a little while to get started but then it would probably spread exponentially.
Living in Southern California, I can tell you that these kinds of fires can go from ignition to conflagration in a matter of minutes.
Okay, I just read the SRD for forest fires, and while the general idea of the rule is good, I find the pace of damage taking/save making near/in the fire to be ridiculous. Players actually near the fire itself should be taking damage/making saves every round.
That being said, if you'd like a suggestion for a mechanic for starting a fire, how about this:
Since a forest fire is treated as a colossal creature, your fire starts at whatever size the ignition starts at, probably tiny at the smallest. You could probably have fine and diminutive ignition sources, but I would rule those have a significant chance of being snuffed out during the growth process.
Once you have determined the size of your ignition fire -- anywhere from tiny to medium, or possibly even large -- when the fire starts to spread out of control, it grows one size category every minute until it reaches colossal. If characters are actively trying to put out the fire, they should have a chance, but each size category above medium should become increasingly harder to extinguish. Huge and gargantuan fires should be very difficult to extinguish manually. I suggest a minimum DC for non-magical attempts to extinguish a gargantuan fire of at least 40. Once a fire reaches colossal, it cannot be extinguished short of magical means or running out of fuel.
I would also suggest adding a rule that every minute a forest fire burns, there is a chance (variable, depending on circumstances, but maybe a 35% to 85% chance?) that any given colossal fire can twin itself, creating another colossal fire that begins moving in a new direction.
If you want to get even more detailed than that, there should be a chance each minute for a given colossal fire to shrink, but how much detail do you want to add?
Some other suggested rules for forest fires:
When a fire hits any kind of previous fire line, or other significant barrier or fire break, the fire should shrink one size category per minute. However, there should be a chance (higher in dry and/or dry conditions) that the fire can jump. Under the right conditions, fires can jump up to mile. When a fire jumps, it begins again in its new location as an out of control medium fire.
When any two fires come into contact, they automatically merge, with standard chances of twining again later remaining normal.
Also, the more I think about it, the more I think that if they're going to treat a forest fire sort of (but not really) like a creature, they should treat being overtaken by the fire as a sort of fire trample effect, as the "creature" moves through the players' spaces.
These mechanics could be fleshed out a little more by anyone so inclined, but this was what I came up with off the top of my head.
Once a fire grows large enough, it begins to create its own weather (firestorm). Personally, at that point I’d treat it as if it were an elemental. If you want to add levels of detail to spice things up, pines in forest fires have been known to spontaneously explode.
Hmm... That should be larger than just one colossal fire. Like, once you hit a certain critical mass of colossal fires within a certain vicinity of each other, you start running the chance that the fire turns into a supercolossal paraelemental, capable of spawning further colossal fires, and packing hurricane force winds (or some other elemental wind attack).
I may have to work on this crunch more, and then find an excuse to throw it at my players.
Ok; my dear Lilith pointed this thread out to me and I have to say I am confused....No one asked the question that should have been asked: What is the EXACT nature of the ignition source (Alchemists Fire)...Is it Napalm in nature, Fuel air, Short duration flash like or is it like the fuel used in Seattle fires some years ago where even water had no effect since the fire was so hot it actually seperated the molecules. All of these things make a difference and act differently. Napalm would the burn quickly no matter the type of forest (Ask any one who has seen it in action).
Ok so let's address some other facts about forest fires: Yes they do make their own weather patterns however unlike some believe it does not take a conflagration to do so; the right topographical conditions can and do add immensly to a fires ability to create as much as destroy. Also something to think about: What ar the preexisting weather conditions...(No a thunder cloud does not mean there will be no fire).
Now to the biggest falacy I have heard. People close to this fire should take damage: I have fought Forest Fires for three years including one that blew out on us. The Crew I was with were 5 feet from flame length and no burns were recieved...None.....Saving throws for being close...Bull!!!!! Listen, Spot, Search rolls are more then enough. Before anyone says..."Well you are an experienced forest fire suppressionist; the characters are not." Ha!!!! People who live in a fire area know it better then most fire suppressionists...In fact we were told to seek the guidance of a local!
So now that I have said this what should one think about?
1. The Ignition Source; Look to the top for this.
2. The time of year; example being that if it is snowing or raining then a standard campfire will not start a fire...There are exceptions to this...Look to Canada for these exceptions but this is a standard rule.
3. The topography; are there a lot of draws, mountain valleys, grasslands. Is there a slope where you plan on fire exposing you characters? If so what is the degree slope?
4. The eco-system; do animals use the area for bedding, mating, living? Do a majority of the plants propagate by FIRE? If so are there many of said plants, shrubs and or trees? Do the natives of the area practise fire harvesting?
6. The purpose of the fire; Accident? Stupidity? Intentional?
Including Forest Fires into the mix of a good game is difficult at best since, as the GM you have to ask: "Why am I doing this?" However this being said if it is done right and with purpose it could be done with artistic value...Nothing says.."No matter how experienced you are I am the great equalizer." Like a forest fire.
How realistic do you want to get with this thing? If you just want a few general guidelines as to what might happen, here is a Forest Fire Simulator.
How realistic do you want to get with this thing? If you just want a few general guidelines as to what might happen, here is a Forest Fire Simulator.
I find it real interesting that some of the very things I was talking about are included in this Simulation. There goes the general :P
How realistic do you want to get with this thing? If you just want a few general guidelines as to what might happen, here is a Forest Fire Simulator.
Having run the simulation 4 times under various conditions I can say unequivocally that it is a joke. There are still things missing even though it covers things like wind-speed and wind direction it does not cover ambient humidity, terrain, forecasted weather changes. But it does say that in the introduction.
Would I use it in a game...Only if I were running a campaign for 3rd graders. Most of my players will ask the tough question that a simulator like that does not even try to answer.
Including Forest Fires into the mix of a good game is difficult at best since, as the GM you have to ask: "Why am I doing this?" However this being said if it is done right and with purpose it could be done with artistic value...Nothing says.."No matter how experienced you are I am the great equalizer." Like a forest fire.
Wow, great response - thank you, all.
Looking over the suggestions and especially the considerations about the impact that a raging forest fire would have on the adventure, I think that I'll go through pains to give them - and their adversaries who are native to the forest - time to extinguish any flames that may begin to grow.
Early on in the game I made it a point to indicate how dry the passing summer had been, so that's were we are as far as climate. It may not come up, but after going on and on in my description of the foliage and how dense it all is, if a flask of alchemist fire goes awry I think I'll have to have a little drama around it.
Thanks again for the input.
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The forest also makes a difference (someone may have mentioned this upthread, but I didn't spot it in a quick glance, lazy me).
A deciduous forest (oak, ash, etc.) will burn, but not necessarily fast or well, and, depending on the climate, is more likely to burn out or be containable. Damp leaves burn fitfully, at best.
A coniferous / evergreen forest (pine) will flash into flame if you even look at it cross-eyed, and the fire will spread so fast that you'll look like one of those Wile E. Coyote caricatures, all soot and ash, with a pair of blinking eyes. The top layer of dry pine needles will burn so fast that damper layers beneath them may barely be warm.
Pine trees have flammable stuff in their needles, and seem to be *designed* to burn fast, so that the fire moves past the tree and leaves it alive, and only minimally damaged, so that it can recover. The unhealthy pine trees are the ones most likely to die in a flash-fire in a pine forest (although some pine forests have other crap in them that will complicate matters, the ideal situation, for the pine tree, is if nothing other than other pine trees exists in the area, and the acidic nature of their shed pine needles tends to discourage competitors).
Deciduous trees seem less well-adapted to fires, and are more likely to burn long enough to suffer damage from which they cannot recover, even if healthy.
The forest also makes a difference (someone may have mentioned this upthread, but I didn't spot it in a quick glance, lazy me).
A deciduous forest (oak, ash, etc.) will burn, but not necessarily fast or well, and, depending on the climate, is more likely to burn out or be containable. Damp leaves burn fitfully, at best.
A coniferous / evergreen forest (pine) will flash into flame if you even look at it cross-eyed, and the fire will spread so fast that you'll look like one of those Wile E. Coyote caricatures, all soot and ash, with a pair of blinking eyes. The top layer of dry pine needles will burn so fast that damper layers beneath them may barely be warm.
Pine trees have flammable stuff in their needles, and seem to be *designed* to burn fast, so that the fire moves past the tree and leaves it alive, and only minimally damaged, so that it can recover. The unhealthy pine trees are the ones most likely to die in a flash-fire in a pine forest (although some pine forests have other crap in them that will complicate matters, the ideal situation, for the pine tree, is if nothing other than other pine trees exists in the area, and the acidic nature of their shed pine needles tends to discourage competitors).
Deciduous trees seem less well-adapted to fires, and are more likely to burn long enough to suffer damage from which they cannot recover, even if healthy.
I just have to say that this was one of the most interesting posts!
Interesting thread too. You mean fire just doesn't burn? lol
A coniferous / evergreen forest (pine) will flash into flame if you even look at it cross-eyed, and the fire will spread so fast that you'll look like one of those Wile E. Coyote caricatures, all soot and ash, with a pair of blinking eyes. The top layer of dry pine needles will burn so fast that damper layers beneath them may barely be warm.
In fact, some conifers require fire to reproduce. Jack pines have cones that will only open and seed with the heat of a fire. The fire burns away the old growth and opens the cones, reseeding the cleared area.
In fact, some conifers require fire to reproduce. Jack pines have cones that will only open and seed with the heat of a fire. The fire burns away the old growth and opens the cones, reseeding the cleared area.
Now that - is simply amazing...gotta love nature, eh?
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In fact, some conifers require fire to reproduce. Jack pines have cones that will only open and seed with the heat of a fire. The fire burns away the old growth and opens the cones, reseeding the cleared area.
Indeed. There are also plant seeds that can't grow out of their own coatings. The coatings *have* to be weakened by the stomach acids of bird or something, and then the seed can finally break free, to find itself surrounded by the rich nutrients of bird poop. Any bird that has evolved strong enough digestive system to damage the seed itself has a chance of discovering that right under the coating is a dose of cyanide, to punish the bird for evolving strong enough stomach acids to damage the actual seed itself!
Nature's got this arms-race thing down cold!