MadDM is an automated numerical tool for the computation of dark-matter observables for generic new physics models. We announce version 3.1 and summarize its features. Notably, the code goes beyond the mere cross-section computation for direct and indirect detection. For instance, it allows the user to compute the fully differential nuclear recoil rates as well as the energy spectra of photons, neutrinos and charged cosmic rays for arbitrary 2 → 𝑛 annihilation processes. This short user guide equips researchers with all the relevant information required to readily perform comprehensive phenomenological studies of particle dark-matter models.