The linguistically simplified instructions describe the concepts of reasonable doubt, criminal intent, and the limited use of evidence of prior convictions. Without these changes, juries are less likely to understand a judge's instructions. In a study using college students, the authors found that those without legal training had difficulty comprehending and applying pattern instructions. In the rewritten instructions, the authors tried to eliminate legal jargon and uncommon words and then had the instructions validated as to legality by legal scholars. A test of the new instructions showed consistently more accurate responses with the revised instructions. Moreover, the revised instructions led subjects to endorse more strongly the correct applications of the legal concepts. Another test, conducted in a setting closely resembling a real trial and using actual jurors as subjects, found similar results. A survey of State trial judges' attitudes toward the new instructions found that the instructions were acceptable and were thought to communicate effectively crucial information to jurors. Thus, the findings may be generalizable to actual jury trials. Moreover, results suggest that jurors with the opportunity to deliberate and who have little jury experience at the outset benefit the most from simplified language. Linguistic improvements in instructions do not, however, shift jurors' decision criteria relative to pattern instructions, though they do help jurors comprehend and apply the instructions to facts more accurately. Ninety-six footnotes, tables, and sample instructions are supplied.