Over several decades, simulation models have become a powerful tool to understand ecosystems and test ecological hypotheses. Yet, at the same time, models are still poorly grasped, trusted, reused and replicated. We hypothesized that the central issue underlying these deficiencies in Ecology and many other scientific disciplines lies the absence of a common procedure to describe simulation models. Since its first version released in 2006, the Overview, Design concepts and Details (ODD) protocol has turned into the standard to describe Agent- or Individual-based Models (ABM/IBM) across sciences. We present here the second update of this protocol, which aimed at easing its integration into academic publications, improving its guidelines, fostering its adoption in the social sciences, and widening its application to any type of simulation model (incl. models other than ABMs/IBMs). Some separate guidance is also provided on how to describe simulation experiments. We thereby hope for ODD to establish as a lingua franca for simulation modelling.