Lantern

A lantern costs 10 G.P. and weighing about 1 lb. Lamp oil is sold by the pint for 1 G.P.

Ordinary light sources have their limits. The Lesser Incantation of the Moon creates magical darkness in which non-magical torches and lamps will not work, and one wind spell can snuff every non-magical fire, torch and lamp within 100 ft. Casting from a scroll requires enough light to read by.