Binding which involves stoichiometries other than 1:1 can be considered multimeric association. Some proteins exhibit this behavior, where a single protein molecule co-assembles with other proteins to form a complex; in other cases, a protein might oligomerize only on binding of a ligand or ligands. The reverse can also happen, with multiple ligands binding to a single protein, etc. The same holds true for some host-guest systems, with these systems exhibiting binding that is not 1:1 , complicating both experimental measurement of binding and computational prediction thereof. In SAMPL7, we worked with experimental collaborators to deliberately ensure the challenge focuses on systems exhibiting 1:1 binding. However, the formation of hostguest multimeric complexes can even depend on the guest identity .