Questions about setting things on fire.

[justsell]

Hello all,

I will try not to cut and paste the rules for setting things on fire from the Campaign book, p.433 but I have a couple of related questions that don't seem to be answered by the text. I'm also not trying to get into physics here.

The questions stem from an attempt to melt through a steel portcullis and yes, I set the castle on fire.

I have a 1d6 burning attack with a 10 divisor: 1d6(10) bu.

Examining the rules as written, 30 points of fire damage will set green wood on fire. Brick will not ignite no matter how much fire damage it takes. Said wood, when it ignites will burn for 1d6-1.

Normally, a 1" wood board has 2DR/18HP so I'm not sure where this fits in and just ignore it. I believe that the attack should use the armor divisor to divide the ignition point from 30 to 3, so 3 points would set the wood on fire. Would this fire then burn at 1d6-1 or 1d6-1(10)? This attack doesn't seem to affect the wood's DR as corrosion would, it just places a fire on top of it. With wood, that doesn't seem to be a huge concern as being flammable, once lit it will continue burning.

If I import an additional level of incendiary and tackle steel at 44DR/88HP, then the DR is a concern because of its lack of flammability. If I get it lit by doing 3 damage over 3 rounds, then I believe that it is on fire. But then what? I'm not trying to dodge ability costs, but I don't know how to add corrosion effect to a separate type of attack. If the fire created is 1d6-1(10), then I think things progress with the bar burning until gone, but if it is just plain 1d6-1, then I think the steel bar would be extinguished as soon as the attack is removed.

Short version:
1. Does the created fire inherit the (10) divisor?
2. Does this do anything to the DR of the item or is there a way to add corrosive effect to ensure that it does?

Thank you,
Justin.

[Bruno]

Originally Posted by justsell

Normally, a 1" wood board has 2DR/18HP so I'm not sure where this fits in and just ignore it.

That's a problem. the DR subtracts from the damage of your attack - if you don't do damage to the wood, it won't ignite. Of course with (10) that DR isn't too bad, but you can't just handwave it away.

18HP is relevant to how long the board has to burn before it's not a barrier/thing you can whack people with.

Originally Posted by justsell

I believe that the attack should use the armor divisor to divide the ignition point from 30 to 3, so 3 points would set the wood on fire.

That's not correct. The armor divisor is used to divide the DR only. You want the Damage Modifier: Incendiary enhancement if you want it to be more flammable - an Incendiary Burning attack treats things it hits as one flammability class more flammable - ie Brick/Metal/Rock can be set on fire with 30 damage.

Fires set by your attack are not armor penetrating or incendiary, they're just fires. If you want continuing awesome fires, that's what Cyclic is for. It's expensive for a reason.

Woods DR is ablative, so it will burn away on its own without need for a corrosive effect. If you want to melt down iron/stone, Link (+10% to both) a Corrosion attack with Damage Modifier: No Wounding (-50%); it will melt DR without doing extra corrosion damage.

[Anthony]

Per RAW, armor divisors have no effect on setting things on fire. If we call a 1d attack 3 damage per second, after 10 seconds it will ignite highly resistant materials (such as green wood) on a 6- on 3d.

The resulting flame is normal flame, and has no armor divisor. There are no standard rule for it reducing DR, and realistically it's not likely to do so on a combat-relevant time scale.

Originally Posted by Bruno

That's a problem. the DR subtracts from the damage of your attack - if you don't do damage to the wood, it won't ignite.

While it maybe should work that way, it actually doesn't. Ignition is based on damage, not injury.

[justsell]

Originally Posted by Bruno

That's a problem. the DR subtracts from the damage of your attack - if you don't do damage to the wood, it won't ignite. Of course with (10) that DR isn't too bad, but you can't just handwave it away.

18HP is relevant to how long the board has to burn before it's not a barrier/thing you can whack people with.



That's not correct. The armor divisor is used to divide the DR only. You want the Damage Modifier: Incendiary enhancement if you want it to be more flammable - an Incendiary Burning attack treats things it hits as one flammability class more flammable - ie Brick/Metal/Rock can be set on fire with 30 damage.

Fires set by your attack are not armor penetrating or incendiary, they're just fires. If you want continuing awesome fires, that's what Cyclic is for. It's expensive for a reason.

Thank you! I didn't realize that the divisor would not apply to burning. I had that feeling that the subsequent fire would be normal, but wasn't sure. If they were upgraded, things could get out of hand pretty quickly. Eventually, the DM and I settled on just recreating the attack as a corrosive, with Incendiary. Pay a few points and move on, but I did want to get an answer in case it popped up again.

[justsell]

Originally Posted by Anthony

Per RAW, armor divisors have no effect on setting things on fire.

Thank you! I looked around but could not find that. That being said, I may just need new glasses.

[Anthony]

Originally Posted by justsell

Thank you! I looked around but could not find that.

This is a case of "not otherwise specified" -- armor divisors reduce DR, and nothing about the rules for setting things on fire mentions DR, therefore armor divisors don't have any effect. If setting things on fire were affected by DR, armor divisors would reduce DR for purposes of calculating whether something is set on fire.