Caillois builds critically on the theories of Johan Huizinga, adding a more comprehensive review of play forms.
[2] According to Caillois, they "may be related" but are mutually exclusive: "Games are not ruled and make-believe.
Examples: Caillois also places forms of play on a continuum from ludus, structured activities with explicit rules (games), to paidia, unstructured and spontaneous activities (playfulness), although in human affairs the tendency is always to turn paidia into ludus, and that established rules are also subject to the pressures of paidia.
It is this process of rule-forming and re-forming that may be used to account for the apparent instability of cultures.
Likewise, ludus and ilinx are incompatible, as there are no structured rules in the state of disorientation; any rules applied are solely to put a brake on the ilinx so as not to turn it into panic.