How do you set a boat or ship on fire?

[RJGrady]

If you have a torch or a lamp full of oil, how does one go about burning something down? I have been unable to locate rules dealing with this. Any help would be appreciated.

[Ciaran Barnes]

Ask your GM? You can consult the table for the hardness or objects and Hp per inch, yada, yada, but given sufficient time and the correct tools/materials, the GM will hopefully just let it happen.

[Lincoln Hills]

Surprisingly (or not), common sense and the rules-as-written are kind of in conflict here. A good first step is getting the GM to agree that fire is a "particularly effective" weapon under the Attacking an Object rule, since wood (hardness 5) will not take any damage unless the fire source you're using inflicts at least 6 hp of damage in a round, and ongoing damage (the usual system for fire rules) don't kick in for an attack that doesn't do any damage to its target. By the rules-as-written, creatures (who ignite after taking any damage at all from alchemist's fire) are more flammable than dried timber coated in tar.

I believe the Council of Thieves AP presented rules specifically for burning buildings, but I don't have them to hand.

[Lamontius]

If I remember correctly, either the Player's Guide for the Skull & Shackles AP or the 1st Chapter of that AP has pretty specific rules for the effects of fire on a ship.

[ReckNBall]

Torches and oils are a good start. Powder if your campaign supports it. Olde timey wooden ships used Oakum and specially shaped wood dowels/wedges etc to patch holes as needed. Oakum is combustible because of the waterproofing. Likely one or five barrels of pitch in the cargo hold as well. Spare canvas for sailcloth, spools of hemp rope. Cargo netting, wooden beams, planks for blocking and bracing to keep the cargo from shifting. You can tell the cartographers and adventure writers never been to sea or below decks at least. Whole lot of stuff missing.

Now if this were a bulk cargo ship (flour, coal, wood) the dust itself becomes explosively flammable/combustible. Remember those cartoons of Yosemite Sam lighting a match in the powder keg room? Same difference. Kablooey.

Say you got a fire started. Smoke from the pitch and hemp fills the space and consumes oxygen. No way to fight it except to flood the compartment, suffocate it or seek volunteers for a last stand. Fire slowly consumes the vessel as the crew seeks the nearest spot of land.

My two cents. Enjoy the horror of a ship board fire.

Edit: Fergie makes an excellent point about combustible vs flammable. I corrected the above statement to reflect that. I used to do this stuff but it seems I've forgotten some of the details. My thanks to him for keeping me on the straight and narrow. Also, no beds would likely be near the bow. Hammocks for the crew are the norm and less affected by the zero gravity chamber that is the forward bow.

[RJGrady]

Skulls and Shackles does indeed have some basic rules. Thank you all for your helpful responses.

[Lincoln Hills]

ReckNBall wrote:

...You can tell the cartographers and adventure writers [have] never been to sea or below decks at least. Whole lot of stuff missing...

I hear that. The "need" to provide 5' squares to fit the combat system doesn't square (ha!) too well with the actual amounts of space available down there. Most of the maps have no storage for the anchor cable. I even saw one ship-map with the galley in the stern, if you can imagine. Not that I'm an authority, but even an armchair enthusiast can catch some of these errors.

[Fergie]

Keep in mind that there is a big difference between flammable materials like tar, dried paper, or hair, and combustible materials like wood, rope, and heavy cloth.

Even the flammable materials require some effort to ignite. Just holding a match to the material might not be enough to get it burning, and just because it starts burning doesn't mean it is going keep burning or burn completely. For example, it is going to take effort to burn a book if you are starting with matches.

Combustible materials require some effort to get going. Holding a lit match under it probably isn't enough to get a burn going. Generally it requires using a more flammable material until it's going, then you have to arrange the material so it can get plenty of air, and the flames and heat can rise to burn more of the material.

Probably the best mundane way to burn a ship would be to go down into the hold and douse some hay with lamp oil, then throw on some broken up crates, and furniture. Get the whole mess burning, and make sure that the fire can get air and climb up to more burnables above. Avoid trying to throw any kind of liquor on there as even the strong stuff is about half water, and alcohol burns at a very low temperature.

Flaming sphere, wall of fire, summoned fire elemental, etc all would work well.

[Lincoln Hills]

The paint locker is an excellent place to find highly flammable material.

[Stockvillain]

Tell one of my players that there's a swarm of something or other?

They burned down half a forest on discovery of a hollow log full of wasps.

Maybe I use too many swarms . . .

[seebs]

There's a general lack of rules for igniting things that aren't specifically intended to be ignited. If you adopt a strict "if the rules don't say, you can't do it", the most important thing is that while you can use oil or alchemist's fire to burn through a piece of wood, doing so does not produce additional heat, so you can't "start a fire" that would then burn other things.

To be fair, if you've ever tried to ignite a log without a fair amount of time and effort to spend on intermediate-sized things to light on fire, this isn't totally unreasonable for most purposes. But basically, in Pathfinder, a fire sweeping through a residential district in a city Can't Happen, because there's no mechanism for a burning house to cause other houses to also burn.

That this almost never comes up says a lot.