I had the idea of throwing oil flasks on enemies at level 1, then hitting them with a torch to deal a bunch of bonus fire damage.
PHB 152:
If the target takes any fire damage before the oil dries (after 1 minute), the target takes an additional 5 fire damage from the burning oil.
PHB 152:
If you make a melee attack with a burning torch and hit, it deals 1 fire damage.
A flat 6 fire damage is pretty potent at level 1, but does the oil remain or does it burn out in a flash when hit (since it has no damage over time) when hit?
If not there is potential for a dual torch wielding PC to throw down 12 fire damage per round, or for multiple PCs to deal 6 damage per torch per PC per round.