A Practice Note describing how to represent plaintiffs, also called relators, in cases brought under the False Claims Act (FCA). This Note describes the elements of the FCA, common fact patterns in FCA cases, how to assess potential cases, pitfalls to avoid, including the public disclosure bar and first-to-file bar, filing a complaint under seal, preparing for the relator meeting, assisting the government during its investigation, litigating cases where the government does not intervene, settlement, and seeking the relator's share, attorneys' fees, and shares of alternate remedies. This Practice Note is based on federal law with references to state laws where applicable.