Refined Oil (3.5e Equipment)
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Contrary to conventional oil, refined oil should not be burned in a lamp or lantern, as it mixes with air and has an explosive hazard. Refined oil is sometimes used for heating buildings or to power vehicles.
You can use a flask of refined oil as a splash weapon. It takes a full-round action to prepare a flask with a fuse and light it or a move action to light one that already has a fuse. Treat the attack as a ranged touch attack with a range increment of 10 feet.
A direct hit deals 1d10 points of fire damage and the target catches on fire, with the effects and first save starting during the next round, and all creatures adjacent to the splash must succeed on a DC 15 reflex save or likewise be set on fire. If the flask is thrown at a specific tile instead of at a creature, the save to avoid catching on fire is DC 20 for that tile and a successful save moves out of that tile. In addition, the tile is treated as if it had been covered with refined oil and lit.
You can pour a pint of refined oil on the ground to cover an area 5 feet square, provided that the surface is smooth. If fire is brought into that tile, the oil ignites and burns for 5 rounds, dealing 1d4 points of fire damage to each creature in the area.
You can throw a pint of refined oil without lighting it. If you do, the target creature or square is covered in oil. A creature covered in oil immediately catches on fire if it comes within 5 feet of a flame.
If refined oil is splashed on a tile or creature and not lit for 5 rounds or more without being lit, part of it vaporizes and becomes highly flammable. The vapor cloud has a radius of 5 feet. If a flame is within this cloud (including fire magic), the cloud will explode. The explosion does 2d6 fire and bludgeoning damage to all creatures within the cloud (Reflex DC 15 half), and 1d6 to those within 5 feet of the cloud (Reflex DC 12 half). If the oil was on a creature, it catches on fire (no save, DC 15 to put out). If it was not, it burns for 3 rounds on the tile it was spilled on.
The cloud can be smelled by any creature with a sense of smell. The cloud remains for 10 minutes if the oil is removed. In moderate wind, it dissipates in 4 rounds; in strong wind, it dissipates in 1 round. If a character spends a minute or more in the cloud, it acts as an inhaled poison (DC 12) that deals initial damage 1d3 Wis and secondary damage 1 Con.
These rules work for any volatile, refined oil, such as gasoline or butane. For a less volatile but still highly flammable oil, remove the sections concerning the vapor cloud.
Refined oil costs 21 gp per flask but is not usually available in shops. It can be made with a successful DC 20 Craft(Alchemy) check. The raw materials consist of 5 flasks of oil (5 sp) and components for refining equipment (65 sp). This substance does not require any spellcasting ability to create.