A contract is a binding agreement between two or more parties. This agreement creates one or more obligations. Each party to a contract is legally bound to do, or to refrain from doing, certain acts. The essence of a contract is that by mutual agreement, parties create obligations that can be legally enforced.
We are assuming such an lottery pool agreement to be lawful in the state of the Participants. This form is a generic example that may be referred to when preparing such a form for your particular state. It is for illustrative purposes only. Local laws should be consulted to determine any specific requirements for such a form in a particular jurisdiction.