A terawatt-class laser, based on the amplification of subpicosecond pulses in XeCl discharge amplifiers, is described. The system generates 250-mJ, 335-fsec pulses at a sustained 1-Hz repetition rate. Using f/3.7 optics, focal-spot dimensions of 3.4 microm x 4.1 microm are measured for the fully amplified output beam, thus demonstrating a mean focalvolume intensity of 4.6 x 10(18) W/cm(2). With f/l optics, this system is therefore capable of producing a focused intensity of 6.4 x 10(19) W/cm(2).