A delayed blast fireball can Detonate up to 5 rounds after the spell is cast. The spell generates a searing explosion of flame that detonates with a low roar and deals 1d6 points of fire Damage per Caster Level (maximum 20d6) to every Creature within the area. Unattended objects also take this Damage. The explosion creates almost no pressure.

The glowing bead created by delayed blast fireball can Detonate immediately if you desire, or you can choose to delay the burst for as many as 5 rounds. You select the amount of delay upon completing the spell, and that time cannot change once it has been set unless someone touches the bead. If you choose a delay, the glowing bead sits at its destination until it detonates. A Creature can pick up and hurl the bead as a thrown weapon (range increment 10 feet). If a Creature handles and moves the bead within 1 round of its detonation, there is a 25% chance that the bead detonates while being handled.

The delayed blast fireball sets fire to combustibles and damages objects in the area. It can melt metals with low melting points, such as lead, gold, copper, silver, and bronze. If the Damage caused to an interposing barrier shatters or breaks through it, the delayed blast fireball may continue beyond the barrier if the area permits; otherwise it stops at the barrier just as any other spell effect does.