Synthetic systems with final planetary masses most similar to the Trappist-1 system. The mass difference to the observed masses (Agol et al. 2021) are −0.17 M_⊕, 0.14 M_⊕, −0.15 M_⊕, and 0.00 M_⊕. Thin lines denote the evolution over time of individual planets. If they stop without ending in a colored dot, the corresponding embryo was ejected or accreted by a more massive planet. Despite closely matching in total mass, significant differences between systems are visible.