Upon casting the lightning bolt spell, the wizard releases a powerful stroke of electrical energy that inflicts damage to each creature within its area of effect. The bolt begins at a range and height decided by the caster and streaks outward in a direct line from the casting wizard. The lightning bolt may set fire to combustibles, sunder wooden doors, splinter up to a half-foot thickness of stone, and melt metals with a low melting point (lead, gold, copper, silver, bronze). If the damage caused to an interposing barrier shatters or breaks through it, the bolt continues. A bolt can breach up to a foot of wood or half a foot of stone.
The lightning bolt's area of effect is chosen by the spellcaster: either a forked bolt 10 feet wide and 40 feet long or a single bolt 5 feet wide and 80 feet long. If a bolt cannot reach its full length, because of an unyielding barrier (such as a stone wall), the lightning bolt reflects from the surface at an angle equal to the angle of incidence, like light off a mirror.
Note: This version of lightning bolt originally appeared in the 2nd Edition Player's Handbook for Advanced Dungeons & Dragons from TSR. Its use here is for the purposes of providing context for the campaign only.