Before you decide to engage in contested litigation for child custody you should consider what is involved. By the numbers it will be explained.

1. Primary caretaking parent . Judges usually decide child custody cases on the basis of who, historically, has been the primary caretaking parent, that is, who has been there for the children.
2. A smoking gun in the hand of the primary caretaker . The primary caretaker will not win if she has a smoking gun in her hand. A smoking gun is that despite the fact that she was the primary caretaker, she was neglectful of the children's health care needs, their nutrition, she left them home alone, she is a drunk, she is on dope etc.
3. In a close case the "shrink factors" count . If child custody is a close shot, the judge will determine it by the "shrink factor", that is, is one parent psychologically more stable and therefore more likely to be the better custodial parent. This is determined by the parents being evaluated by a mental health professional through a clinical interview and psychological testing.
4. The first step is mediation . First the lawyers file court papers stating that each party wants custody. This lets the judge know that there will be a custody fight. The judge will then enter an order requiring the parents to participate in mediation. A mediator does not decide the custody issue. The mediator attempts to bring the parties to a custody agreement. My experience is that most custody cases are not resolved by mediation, but considering the alternative of going on to litigation, mediation is certainly worth a shot. Considering that there is some chance for resolution of the case through mediation, the parties should be well prepared for the litigation by their lawyers. A parent should not go into mediation without advice from a lawyer re how to handle the procedure.
5. Investigation and evaluation . Here we come to the "shrink factor." A court may be asked to enter an order for a person to investigate and evaluate the issue of custody. Usually this person has the authority to inquire of physicians, teachers, friends and neighbors. This report/evaluation is given to the judge. If there is a recommendation, it is only that. The decision is the judge's and not that of the evaluator/investigator. The recommendation, however, is significant and usually leads to a settlement of the case. The reason is that the judge will give significant weight to the recommendation.
6. Appointment of lawyer for child . The judge has the discretion to appoint a lawyer for the child, either on the judge's own motion, or motion of either party. The actual purpose of having a lawyer for the child is to assure that the child's best interests are represented. In fact the parties will usually ask for a child to be represented by a lawyer, who is called a guardian ad litem, if that parent feels there will be an advantage for him and or her gained thereby.
7. The cost of a custody trial . Ninety-five percent of all litigation cases are settled and do not go to trial. Custody cases have a significantly lower chance of being settled, but nevertheless the majority of them are settled short of trial. How much the fees and costs will be depends on how far up the litigation ladder you go. If you go to the top, that is there is a trial, the custody litigation will cost you about as much as the cost of a luxury car. This is not because lawyers charge a set fee for child custody work. As a rule, lawyers charge by the hour for their work. Most lawyers do not have payment plans, that is, so much per month until the bill is paid.