Potential outcomes from our simulations. The system begins with (a) an outer moonlet from a previous impact/merger that has migrated to a distant orbit and an inner moonlet produced by a recent impact that begins at the Roche limit. The system evolves until either (b) both moonlets infall individually or after a merger, impacting the proto-Earth (in rare cases one moonlet can be ejected (not shown)), (c) the moonlets merge into a larger moonlet that remains stable and continues to tidally evolve outward, or (d) the inner moonlet infalls while the outer moonlet remains stable (in rare cases the outer moonlet infalls and the inner moonlet remains stable). Note that the starting inclinations need not be coplanar (as assumed in (a)), and that the final inclination of the moonlets could change. To build the Moon from multiple moonlet-generating impacts, the probability of mergers and outer moonlet survival (where the outer moonlet could be a product of a previous merger) must be high.