A fireball is an explosive burst of flame, which detonates with a low roar and
delivers damage proportional to the level of the wizard who cast it–1d6
points of damage for each level of experience of the spellcaster (up to a maximum of
10d6). The burst of the fireball creates little pressure and generally
conforms to the shape of the area in which it occurs. The fireball fills an area equal
to its normal spherical volume (roughly 33,000 cubic feet–thirty-three
10-foot x 10-foot x 10-foot cubes). Besides causing damage to creatures, the fireball
ignites all combustible materials within its burst radius, and the heat of the
fireball melts soft metals such as gold, copper, silver, etc. Exposed items
require saving throws vs. magical fire to determine if they are affected, but
items in the possession of a creature that rolls a successful saving throw are
unaffected by the fireball.

The wizard points his finger and speaks the range (distance and height) at
which the fireball is to burst. A streak flashes from the pointing digit and,
unless it impacts upon a material body or solid barrier prior to attaining the
prescribed range, blossoms into the fireball (an early impact results in an early
detonation). Creatures failing their saving throws each suffer full damage from
the blast. Those who roll successful saving throws manage to dodge, fall flat,
or roll aside, each receiving half damage (the DM rolls the damage and each
affected creature suffers either full damage or half damage [round fractions
down], depending on whether the creature saved or not).

The material component of this spell is a tiny ball of bat guano and sulphur.