A review of the empirical basis for cross-examination covers overt and unconscious partisanship and errors in the perception process. The latter discussion focuses on seeing, hearing, feeling, smelling, and fact acquisition; understanding and retention; and relating and retrieval. A discussion of planning for cross-examination outlines affirmative cross-examination goals and negative/discrediting cross-examination goals. Steps in organizing cross-examinations include starting on a strong point, working objectives into the organizational scheme, organizing crucial segments, asking crucial questions in an environment of maximum safety, and planning for negative cross-examination. Rules for cross-examination cover when not to cross examine, cross-examination in terms of the closing argument, making important points and satisfying objectives early in the examination, not repeating the direct examination, not asking the question if the answer is not known or if it cannot be asked with safety, and not being diverted by helpful admissions on collateral matters. Other rules include not insisting on an answer unless certain it is favorable, not attempting an experiment in the courtroom unless certain of the result, and narrowing the opportunities for the witness to explain impeaching or discrediting material. 37 footnotes.