We consider the semiclassical limit of the spectral form factor K(τ ) of fully chaotic dynamics. Starting from the Gutzwiller type double sum over classical periodic orbits we set out to recover the universal behavior predicted by random-matrix theory, both for dynamics with and without time reversal invariance. For times smaller than half the Heisenberg time TH ∝h −f +1 , we extend the previously known τ -expansion to include the cubic term. Beyond confirming random-matrix behavior of individual spectra, the virtue of that extension is that the "diagrammatic rules" come in sight which determine the families of orbit pairs responsible for all orders of the τ -expansion.Introduction: One of the fascinating quantum signatures of chaos is universal behavior of the correlation functions of the spectral density of energy levels, for general hyperbolic dynamics [1]. Three universality classes were suggested by Dyson and Wigner; one, called "unitary", has no time reversal symmetry, while the other two do have Hamiltonians H commuting with an antiunitary time reversal operator T ; if T 2 = 1 one speaks of the "orthogonal" class while the "symplectic" case has T 2 = −1. The Fourier transform of the two-point correlator of the level density, called spectral form factor, is predicted by random-matrix theory (RMT) [2] as