Causal sets are a theory that encodes space-time through the causal relations between events. This leads to a fundamentally Lorentzian, discrete, formulation, in which space-time is reduced to partial orders. One possible way to quantize causal sets, is to calculate the path integral over these partial orders. This can either be attempted analytically or explored through Monte Carlo simulations. In this talk I will first introduce causal sets, and then speak about recent work on matter and the path integral in causal sets.