A boostrappable system is a closed system that can replicate. A closed system is different from a bootstrappable system. Unlike a bootstrappable system, it cannot be replicated without external input. Neither requires the transfer of materials inside of the system. A closed system needs the following: Metals: For tools. Wood: For burning (heat, cooking), for tools (for gardening, for cooking), for charcoal (for furnace). Seeds. For growing. Water. For drinking. Sun/Starlight (although this really cheating). For growing plants, for heat. Leaves or straw: For thatching. Mud, and clay: For growing, for pottery (cooking). Fibre: For making clothes. Air: For breathing. For growing plants. Required skillsets are: Thatching. Gardening. Pottery. Blacksmithing.