Our goal in this paper is to describe a QM-derived force field that has the potential to be easily extended to the types of problems usually reserved for standard, transferable force fields, such as host-guest binding in solution, simulation of biomolecular assemblies, and computer-aided drug design. To set up a transferable FF for a small molecule, a user typically performs a QM geometry optimization to fit atomic charges (typically to the QM electrostatic potential), and maybe performs torsional scans for key dihedrals. In order to be competitive with transferable FFs, our FF derivation technique should i) allow users to derive all system-specific bonded and non-bonded FF parameters from these two simple QM input calculations, ii) scale up to relatively large system sizes (e.g. 50-100 atoms), iii) provide parameters suitable for use in mixed simulations (e.g. for the molecule in a solvent or in host-guest simulations), iv) retain the simple functional form of transferable FFs for implementation in the majority of classical MD codes and for use in free energy calculations, v) retain or improve on the accuracy of transferable FFs for modelling of condensed phase properties (and hence implicitly account for many-body effects). That is, we aim to remove any FF limitations associated with parameter transferability, and instead adopt a transferable FF derivation methodology akin to the semi-empirical models routinely used for charge derivation.