Abstract: A pyrotechnic system comprises a plurality of pyrotechnic charges or devices 20 arranged in a matrix of recesses 14 formed in a block 12 of a synthetic resin material.In one embodiment, each device 20 contains a fast-burning pyrotechnic composition 42 arranged to be fired by an electrical primer 50, for producing a flash and/or a bang, and a slow-burning pyrotechnic composition 40 separated from the composition 42 and arranged to be ignited by the firing of the composition 42. Embedded in the composition 40 is a fine wire loop 48 which is ruptured by the burning of the composition 40. The primers 50 of the devices 20 are connected in parallel between two input terminals 52, 54, and each loop 48 is connected to short-circuit the primer 50 of the next device 20 in the firing sequence. The pyrotechnic system is thus self-sequencing.