In mid-1999 the Relativistic Heavy Ion Collider (RHIC) facility will begin accelerating 197Au nuclei to 100 A GeV. The effective temperature in the dense region of overlap when two nuclei collide nearly head on at this energy will reach 1012 degrees Kelvin. At this temperature a basic restructuring of matter is expected to occur, in which the quark and gluon constituents normally confined in hadronic matter form a chirally symmetric deconfined plasma. There are many signatures to help isolate evidence of a transition to a deconfined phase of matter. These include, for example: (1) strangeness saturation on a time scale too short to be accounted for by strangeness exchange interactions in a hadron gas, (2) color screening (vector meson suppression) in the plasma phase, (3) in-medium effects on the mass/lifetime of the vector mesons, (4) the observation of thermodynamic/chemical equilibrium, (5) thermal radiation from a hot plasma, (6) excess heavy flavor production, (7) a discontinuity or change in the correlation between energy density and entropy density, (8) the observation of a long hadronization time, (9) disoriented chiral condensate behavior (isospin or low pt correlations). Each of the RHIC detectors is optimized for the measurement of a number of the above signatures. It is therefore possible because of the very high particle densities at RHIC for these detectors to correlate multiple observables in a single event or in a sample of events. It will thus be possible to isolate events which exhibit correlated non-statistical fluctuations in several observables simultaneously. It will be possible at RHIC to make a self-consistent measurement of the initial conditions, and in particular the gluon distribution in the nucleus. This affords optimal use of perturbative QCD in providing guidance as to the evolution of the early stages of the collision. We review the design and capabilities of the four detectors at RHIC: BRAHMS, PHENIX, PHOBOS, and STAR.