Multi-level-Multi-physics approach. Left: domains on different levels can move and interchange information to follow the self-consistent evolution of the features they model. The different considered levels are the following. Coarsest: plasma treated as a single fluid. Intermediate levels account for multi-fluid approaches (Hall MHD, electron MHD or two fluid) or hybrid (electrons are treated as a fluid but ions are treated kinetically). Finest level: kinetic electrons and ions, both treated as particles. The multi-level approach allows to push beyond the state of the art and model all coupled scales together. The scales are indicated here for the Earth’s magnetotail, as an example.