<Li> Implication - in - fact </Li> <Tr> <Th> Defenses against formation </Th> </Tr> <Tr> <Td> <Ul> <Li> Lack of capacity </Li> <Li> Duress </Li> <Li> Undue influence </Li> <Li> Illusory promise </Li> <Li> Statute of frauds </Li> <Li> Non est factum </Li> </Ul> </Td> </Tr> <Ul> <Li> Lack of capacity </Li> <Li> Duress </Li> <Li> Undue influence </Li> <Li> Illusory promise </Li> <Li> Statute of frauds </Li> <Li> Non est factum </Li> </Ul>

A novation requires the existence of a previous valid obligation