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Igniting an object

jgsugden

Explorer
There are a variety of spells and items that ignite flamable objects. There is not a huge amount of guidance on what this means. How have DMs ruled it?

Let's say a 1st level firebolt that deals 1 damage will not destroy a large flamable object in one shot - but it would ignite it per the description. When does it take more damage? How much?

A fire elemental that ignites something continues to deal 1d10 damage per round. Is that a standard that DMs use, or do DMs have different damage for different types of fire sources? Spilling oil on something deals 5 additional fire damage if they take fire damage - that is about the same....
 

Shiroiken

Explorer
I would go with 5 damage per round, but really anything listed as flammable will just burn away areas, like the web spell does. So if you had a paper wall, 1 point of fire would ignite it, and begin to spread the destruction around it.
 

the Jester

Legend
I mostly handwave it and use it as an excuse to catch areas the pcs are fighting in on fire, adding to the drama. I also have area of effects damage objects and structures when the pcs use them; there's at least one big tower on the verge of collapse in a nearby ruined city due to their actions with the shatter spell.
 

Paul Farquhar

Adventurer
Produce Flame into a thatched roof can lead to the docks burning down.

But my character wasn't anywhere near at the time officer.
 

aco175

Explorer
Generally I do not have things catch fire. I kind of picture magical fire going off so fast or hot and not having time to catch things on fire. I do allow things like firebolt to be modified to light a fire or torch, sort of toning down the spell. This can be prestidigitation as well making a Bic lighter.

If the player wants the PC to catch something on fire I may let them, but this may have only come up a few times over the last 20 years.
 

Maxperson

Morkus from Orkus
There are a variety of spells and items that ignite flamable objects. There is not a huge amount of guidance on what this means. How have DMs ruled it?

Let's say a 1st level firebolt that deals 1 damage will not destroy a large flamable object in one shot - but it would ignite it per the description. When does it take more damage? How much?

A fire elemental that ignites something continues to deal 1d10 damage per round. Is that a standard that DMs use, or do DMs have different damage for different types of fire sources? Spilling oil on something deals 5 additional fire damage if they take fire damage - that is about the same....
This is one of those rulings over rules moments. You're going to have to look at the situation. Is it a large ball of thin, super dry paper? It takes a lot of damage really fast. Is it a rock covered in some dry moss? It takes only a little and then goes out. Are you in a desert? A swamp? Circumstances will change how this should play out.
 

jgsugden

Explorer
So how have DMs ruled it is the question? What 'ruling over rules' approach did you take if you took that approach?

What objects do you consider to be flammable enough that a firebolt will ignte it?

Paper?
A pile of cloth?
Wood furniture?
A dried up bush?
A living tree?
 
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Ovinomancer

Explorer
Flammable means can be easily set on fire. I use the match test -- if a lit match touches the object, does it catch fire? Not held onto, but touches. If so, the item catches fire. Oil is flammable. Paper is flammable. Thatch roofs are generally not flammable (despite what movies show -- people tend not to make their houses firetraps). Wooden doors are not flammable. Curtains may be flammable.

In general, unless whatever your considering is easily set on fire, it shouldn't ignite from these spells.

Now, onto your question about fire damage. I got with a d6 if there is a fire in the space. This is how much damage a square of burning oil does (or if you're doused in oil) so it's a decent judge of spread out fire damage. If it's a conflagration, though, where the entire space and those next to it are on fire, then I'd be more likely to treat those spaces as impassible or instant death (absent protections). You can't run through a roaring bonfire and live, for example. In between, for a major fire that isn't a roaring inferno, likely 2d6 plus a d6 for each adjacent space fully on fire.
 

Maxperson

Morkus from Orkus
Flammable means can be easily set on fire. I use the match test -- if a lit match touches the object, does it catch fire? Not held onto, but touches. If so, the item catches fire. Oil is flammable. Paper is flammable. Thatch roofs are generally not flammable (despite what movies show -- people tend not to make their houses firetraps). Wooden doors are not flammable. Curtains may be flammable.
This makes total sense if the amount of initial fire damage is the equivalent of a match. If it's doing say 12 points of fire damage to the target, though, it's a hell of a lot hotter than a match and will catch correspondingly more items on fire in that instant.
 

jgsugden

Explorer
This makes total sense if the amount of initial fire damage is the equivalent of a match. If it's doing say 12 points of fire damage to the target, though, it's a hell of a lot hotter than a match and will catch correspondingly more items on fire in that instant.
It is tough to say what would and would not catch fire - it is going to be based primarily upon your mental picture. A firebolt spell that deals 12 points of damage is still just a mote of fire - that is the decription of the spell? Does it hit and burn for a moment or disappear in an instant?

I was thinking of this as a general rule:

There are three classes of items in terms of flamability:

1.) Highly flammable - Any fire damage will catch them on fire. Example - Oil.
2.) Ignitable - If it takes half of its HP in fire damage it catches fire. Examples - Paper, wood.
3.) Non-flammable - Unless it is soaked in something highly flammable, it will not catch fire. Examples - Stone, metal.
 

Maxperson

Morkus from Orkus
It is tough to say what would and would not catch fire - it is going to be based primarily upon your mental picture. A firebolt spell that deals 12 points of damage is still just a mote of fire - that is the decription of the spell? Does it hit and burn for a moment or disappear in an instant?

I was thinking of this as a general rule:

There are three classes of items in terms of flamability:

1.) Highly flammable - Any fire damage will catch them on fire. Example - Oil.
2.) Ignitable - If it takes half of its HP in fire damage it catches fire. Examples - Paper, wood.
3.) Non-flammable - Unless it is soaked in something highly flammable, it will not catch fire. Examples - Stone, metal.
That seems reasonable. For myself, I'd probably give it a chance to catch fire at 25-49% and guarantee it at 50%
 

Ovinomancer

Explorer
This makes total sense if the amount of initial fire damage is the equivalent of a match. If it's doing say 12 points of fire damage to the target, though, it's a hell of a lot hotter than a match and will catch correspondingly more items on fire in that instant.
The trigger isn't damage, though, it's the property of being "flammable." This has a meaning, and the match test is a reasonable way of explaning the meaning of "flammable."

Besides, hitpoints have no meaning in and of themselves. 12 hp out of 13 is the sane, finctionally, as 13 hp out of 13. The increase in damage might just be a measure of application rather than increased scale. The thing about abstractions is that you shouldn't infer additional information from them -- it's not there to begin with.
 

Maxperson

Morkus from Orkus
The trigger isn't damage, though, it's the property of being "flammable." This has a meaning, and the match test is a reasonable way of explaning the meaning of "flammable."
The triggers are both the spell and the flammable property, not just the flammable property. A flammable object all by itself doesn't burst into flame. The fire spell hitting an object that is not flammable does not ignite it on fire. It requires both triggers to be present.

The match test might seem reasonable to you, but it's far too unrealistic and unreasonable for me. A match pales in comparison to a fireball, so it fails miserable to describe what might catch on fire due to a fireball.

Besides, hitpoints have no meaning in and of themselves. 12 hp out of 13 is the sane, finctionally, as 13 hp out of 13.
It's a metric that gives an approximation of power. Something that deals 1 point of damage is one tenth as strong as something that deals 10. The functionality you are referring to is required in order to make the game enjoyable to enough people to warrant making the game in the first place. Having to track statuses and penalties every X damage is not enjoyable to a lot of people and complicates the game too much. You shouldn't read too much into 1 hit point out of 20 being functionally the same as 20 out of 20.

Hit points are only abstract in how you lose them, not in the power of that which deals the damage.

The increase in damage might just be a measure of application rather than increased scale.
Except not. A fireball blows up and hits everything in a 20' radius. Scorching ray creates 3 rays of flame 120' long. Those are objectively on a scale that dwarfs a match. There is no possibility that the damage is a measure of application and not scale. A match won't even do 1 point of damage to something. It literally takes a fully lit torch to deal 1 point of damage.
 

5ekyu

Explorer
So how have DMs ruled it is the question? What 'ruling over rules' approach did you take if you took that approach?

What objects do you consider to be flammable enough that a firebolt will ignte it?

Paper?
A pile of cloth?
Wood furniture?
A dried up bush?
A living tree?
Flammable foes not normally mean capable of burning but easily set on fire.

So dry papr, brush, some woods some cloth etc would qualify.

Living trees, solid not dried out wood, anything even remotely wrt... nah.

My rule of thumb would be "if I would consider using this as the starter for a fire (kindling, paper wadding. Etc) then I consider it flammable. If it's something I would only add once a flame was going - nah.

So, maybe fireball in the open igjites the drying autumn leaves of a tree but they will have to burn a while before they ignite the bigger branches or trunk.

As others said, mostly it's an option that can createxterrain.
 

Ovinomancer

Explorer
The triggers are both the spell and the flammable property, not just the flammable property. A flammable object all by itself doesn't burst into flame. The fire spell hitting an object that is not flammable does not ignite it on fire. It requires both triggers to be present.

The match test might seem reasonable to you, but it's far too unrealistic and unreasonable for me. A match pales in comparison to a fireball, so it fails miserable to describe what might catch on fire due to a fireball.
Does it? Describe a fireball. Is it a raging inferno of fire that sits in an area for six seconds, or is it a brief flash of high temperature? Describe the damage done to a character with 103 hp that is inside the blast of a 42 hp damage fireball. Do the same for a 30 hp character in the same fireball. Now, describe the damage to the iron anvil in the same fireball. To the heavy wooden door. To the ancient wall hangings. To the wooden crates. To the pile of papers.

You can't find a common thread to do this because it's all abstract. The rules of the game say that a fireball will ignite flammable objects. Flammable means 'burns easily'. This is a concrete thing you can decide. I'm not saying there's room around the edges for judgement calls on what burns easily, but the match test is a great one for a rule of thumb that doesn't involve inventing rules about how much damage the spell does affecting the flammability of the objects the spell interacts with. Flammability is a property orthogonal to the damage the spell might do.


It's a metric that gives an approximation of power. Something that deals 1 point of damage is one tenth as strong as something that deals 10. The functionality you are referring to is required in order to make the game enjoyable to enough people to warrant making the game in the first place. Having to track statuses and penalties every X damage is not enjoyable to a lot of people and complicates the game too much. You shouldn't read too much into 1 hit point out of 20 being functionally the same as 20 out of 20.

Hit points are only abstract in how you lose them, not in the power of that which deals the damage.
If a target has 1 hitpoint, the spell kills them. If the target has 100 hitpoints, the spell kills them. This isn't a 100 fold difference in power, it's about the nature of the target. HP damage is abstract and always relative to the target. A 30 hp fireball is not 25% less effective at setting things on fire than a 40 hp fireball. They both ignite flammable objects.

[/quote]
Except not. A fireball blows up and hits everything in a 20' radius. Scorching ray creates 3 rays of flame 120' long. Those are objectively on a scale that dwarfs a match. There is no possibility that the damage is a measure of application and not scale. A match won't even do 1 point of damage to something. It literally takes a fully lit torch to deal 1 point of damage.[/QUOTE]
Well, duh, of course they're bigger than a match. I never said this was a comparison for spell area. I said it was a good rule of thumb to determine "flammable." Both scorching ray and fireball ignite flammable objects the same way, but they're very different in scale between 3 instantaneous bolts of fire and a 20' radius instantaneous eruption of fire. Are you suggesting that your metric for what catches on fire is going to be different between a fireball and scorching ray? If so, you have much bigger issues that the match test, good luck with them.
 

Maxperson

Morkus from Orkus
Does it? Describe a fireball. Is it a raging inferno of fire that sits in an area for six seconds, or is it a brief flash of high temperature?
It really doesn't matter. The higher the temperature, the shorter the duration required to set things on fire.

Describe the damage done to a character with 103 hp that is inside the blast of a 42 hp damage fireball. Do the same for a 30 hp character in the same fireball. Now, describe the damage to the iron anvil in the same fireball. To the heavy wooden door. To the ancient wall hangings. To the wooden crates. To the pile of papers.
Again, this is a function of hit points, not damage. Hit points are abstract, not damage. 42 points of fire is 42 points of fire.

You can't find a common thread to do this because it's all abstract.
No. Just the hit points are abstract, not the damage. Fireballs do fire damage. The don't do luck damage. They don't do skill damage. The rules are very clear about that. Hit points are abstract, which is why you can lose luck hit points or skill hit points, etc. The loss of those luck/skill hit points was due to fire damage, though, and nothing else.

I'm not saying there's room around the edges for judgement calls on what burns easily, but the match test is a great one for a rule of thumb that doesn't involve inventing rules about how much damage the spell does affecting the flammability of the objects the spell interacts with. Flammability is a property orthogonal to the damage the spell might do.
I could drive an 18 wheeler through the room around those edges. A match isn't even remotely close to being as hot or damaging as even the weakest fire spell.

If a target has 1 hitpoint, the spell kills them.
If a target has 1/2 of a hit point fully healed, it kills them. Otherwise it just knocks them out.

Well, duh, of course they're bigger than a match. I never said this was a comparison for spell area. I said it was a good rule of thumb to determine "flammable." Both scorching ray and fireball ignite flammable objects the same way, but they're very different in scale between 3 instantaneous bolts of fire and a 20' radius instantaneous eruption of fire. Are you suggesting that your metric for what catches on fire is going to be different between a fireball and scorching ray? If so, you have much bigger issues that the match test, good luck with them.
My metric is spell level. It gives you an idea on the power of the fire. A 2nd level scorching ray is not as likely to ignite things as a 3rd level fireball, but is more likely than a 1st level burning hands. All three will dwarf a match for igniting things, though. A match won't light a thatch roof. A fireball will, and easily.
 

Ovinomancer

Explorer
It really doesn't matter. The higher the temperature, the shorter the duration required to set things on fire.



Again, this is a function of hit points, not damage. Hit points are abstract, not damage. 42 points of fire is 42 points of fire.



No. Just the hit points are abstract, not the damage. Fireballs do fire damage. The don't do luck damage. They don't do skill damage. The rules are very clear about that. Hit points are abstract, which is why you can lose luck hit points or skill hit points, etc. The loss of those luck/skill hit points was due to fire damage, though, and nothing else.



I could drive an 18 wheeler through the room around those edges. A match isn't even remotely close to being as hot or damaging as even the weakest fire spell.



If a target has 1/2 of a hit point fully healed, it kills them. Otherwise it just knocks them out.



My metric is spell level. It gives you an idea on the power of the fire. A 2nd level scorching ray is not as likely to ignite things as a 3rd level fireball, but is more likely than a 1st level burning hands. All three will dwarf a match for igniting things, though. A match won't light a thatch roof. A fireball will, and easily.
Well, then, I'm very happy your house rule works for you. In the meantime, the definition of flammable is not tied to spell level or damage value in game. In the real world, flammablity is easily demonstrable with the match test. If you want to add houserules to your game to get the feel you want, have at, but none of your arguments so far appear in the rules, which are the baseline I'm referring to.

I am curious, though, what properties does damage have that's not related to hitpoints? I've looked through the rules but can only find that damage values are subtracted from hitpoints and that they have no other interactions in the rules outside of hitpoints. Yet, you've claimed that are their own thing and aren't tied to hitpoints. What page is that on?
 

Maxperson

Morkus from Orkus
Well, then, I'm very happy your house rule works for you. In the meantime, the definition of flammable is not tied to spell level or damage value in game. In the real world, flammablity is easily demonstrable with the match test. If you want to add houserules to your game to get the feel you want, have at, but none of your arguments so far appear in the rules, which are the baseline I'm referring to.
Wood and clothing appear on lists of flammable items.

I am curious, though, what properties does damage have that's not related to hitpoints? I've looked through the rules but can only find that damage values are subtracted from hitpoints and that they have no other interactions in the rules outside of hitpoints. Yet, you've claimed that are their own thing and aren't tied to hitpoints. What page is that on?
I said that damage is not abstract like hit points. You can't cast a fireball and do ice damage. You can't cast a fireball and do luck damage. You can't cast a fireball and to divine providence damage. Unless you can change the energy type, it always does fire damage. Hit points on the other hand can be whatever you need them to be.
 

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