As a general rule, when creating a class hierarchy, the classes with the most generalised behaviour are higher up the hierarchy than classes with more specialist behaviour. So a Thing class with just a name and a description, would be the ancestor of a Treasure class which has a name, a description and, addi-tionally, a value; the Thing class might also be the ancestor of some other special-ist class such as a Room which has a name, a description and also exits – and soon