Illinois Fathers Petition To Determine Parentage and-Or Custody-Visitation and Set Child Support is a legal document that is used by fathers in Illinois to establish paternity and/or custody and visitation rights as well as to set child support payments. This document is typically used when the father is not the legal father of the child, or when the father is seeking visitation rights. There are three types of Illinois Fathers Petition To Determine Parentage and-Or Custody-Visitation and Set Child Support: a Petition to Establish Paternity, a Petition for Custody and Visitation Rights, and a Petition to Set Child Support. The Petition to Establish Paternity establishes that the father is the legal father of the child and is used to establish paternity rights. The Petition for Custody and Visitation Rights is used to establish the father's rights with regard to visitation and custody of the child. The Petition to Set Child Support is used to set the amount of child support the father is responsible for.