Oil is an inflammable substance in Dragon's Dogma.
Oil is the fuel that keeps lanterns burning. It is a must when exploring dark dungeons or during the night.
Oil is carried in the form of Oil flasks, and can be obtained by filling Empty Flasks from Oil pots, found in the world and it can be bought from vendors.
Throw oil containers or use Oil Arrows to inflict tarring on enemies, which increases fire damage and the likelihood of burning.