As highlighted in Sections 2 and 3, modelling nucleation from solution introduces unique theoretical and practical challenges. As such, a range of different approaches have been applied to this problem, populating a variety of methods that span epistemic interpretations of the role of simulations. On the one hand, there is the application of molecular simulation methods to estimate physical parameters appearing within independently established theoretical frameworks. On the other hand, molecular simulations can be utilised as computational experiments, yielding a direct observation of the fundamental steps underpinning crystal nucleation from solution. These types of simulations contribute to the assessment of existing theoretical frameworks and, if necessary, to the development of new ones. The space between these two simulation extremes is populated by a plethora of different approaches that vary not just in their technical implementation but also in the degree to which they rely on reference theoretical frameworks to yield estimates of nucleation kinetics and mechanisms. In Figure , we provide a graphical representation of a variety of such methods in relation to their reliance on CNT and its underpinning assumptions. At one extreme, if computational resources were not an issue, then one could perform many, large-scale MD simulations for sufficient enough time to observe crystal nucleation and growth, and, following validation of an appropriate reaction coordinate, extract kinetics for nucleation using Poisson statistics (see right of Figure ), requiring no a priori assessment of the mechanism and rate equation for nucleation is necessary. Unfortunately, the computational cost here means that this approach is unlikely to succeed in most cases. At the other extreme, if one assumes a mechanism from established theories, such as CNT, equilibrium MD simulations or experimental data can be leveraged to plug into the theory master equation (see left of Figure ). This approach can be very cheap; however, estimates of crystallization rates here are likely to be erroneous (given the shortcomings of CNT and observations from experiments discussed in section 2) and no insight into the mechanism is gained, as well as this approach being largely unsatisfying for the simulator. The simulation methods we discuss below fall between these extremes and were either developed to simulate nucleation directly or to simulate rare events more generally.