Systems theory emphasizes the mediator's role as enabler rather than changer. It also permits realistic assessments of family relationships and the effects of changes in the relationships. To understand a child custody dispute from a family systems perspective, a mediator must identify the main actors, their motives and needs, the options for mutual gain, the prospects for settlement, and the existing patterns of parenting. The seven typical family patterns provide varying prospects for mediation. These patterns have emerged from an analysis of 35,000 families who have used the Los Angeles Conciliation Court since 1977. The seven patterns are: (1) two parents who are not involved in relationships with any third party, (2) families in which one or both parents have remarried, (3) families in which the child has declared a choice about the parent with which to live, (4) families in which one parent has a severe emotional problem or other problem limiting the ability to parent, (5) parents enmeshed in an emotional morass, (6) families in which grandparents as well as parents are involved in raising children, and (7) families experiencing a change of circumstance, such as one parent's move away from the community. Figures and 9 references.