Pyrotechnics turns a fire into either a burst of blinding fireworks or a thick cloud of choking smoke, depending on the version the character chooses.
Fireworks: The fireworks are a flashing, fiery, momentary burst of glowing, colored aerial lights. This effect blinds creatures within 120 feet of the fire source for 1d4+1 rounds (Will negates). These creatures must have line of sight to the fire to be affected. Spell resistance can prevent blindness. In addition to the obvious effects, a blinded creature suffers a 50% miss chance in combat (all opponents have full concealment), loses any Dexterity bonus to AC, grants a +2 bonus to attackers’ attack rolls (they are effectively invisible), moves at half speed, and suffers a –4 penalty on most Strength- and Dexterity-based skills.
Smoke Cloud: The smoke is a writhing stream of smoke billowing out from the source and forming a choking cloud. The cloud spreads 20 feet in all directions and lasts for 1 round per caster level. All sight, even darkvision, is ineffective in or through the cloud. All within the cloud suffer –4 penalties to Strength and Dexterity scores (Fortitude negates). These effects last for 1d4+1 rounds after the cloud dissipates or after the character leaves the area of the cloud. Spell resistance does not apply.