Q: If someone litigated in civil court and lost, can he then turn around and sue in beis din?

A: If the plaintiff lost the case in civil court and then turns around and tries to sue in beis din, there is a dispute among the authorities whether beis din should address the case and summon the defendant. The Rema rules not to, either as a penalty to the plaintiff for suing in civil court or because, through his actions, the plaintiff implicitly accepted the ruling of civil court as binding. Nonetheless, if the decision of the courts was clearly false — even according to civil law — the defendant is still obligated to pay the plaintiff any money that he knows he owes him (C.M. 26:1; Nesivos 26:2).

Even in situations where beis din will address the case, the plaintiff must first cover the defendant’s legal expenses (see Divrei Chaim, C.M. 2:1).