Explanation:

- Option 1: Illegal

Contingent contracts are not illegal. They are valid, provided the event they hinge upon is lawful and possible.

- Option 2: Not contract at all

Contingent contracts are indeed contracts. They are agreements that hinge on the occurrence or non-occurrence of an uncertain future event.

- Option 3: Wagering in nature

While some contingent contracts may seem like wagers, they are not necessarily so. A wagering contract specifically involves mutual promises where gain or loss depends on an uncertain event. Not all contingent contracts qualify as such.

- Option 4: None of the above

None of the given options accurately describe contingent contracts.

Correct Answer: Option 4 - None of the above