Jury nullification is a mechanism and a defense which allows the jury, as representatives of the community, to disregard both law and evidence and acquit defendants who have violated the letter, but not the spirit, of the law. The 3 levels of instructions were: standard pattern instructions (SPI) which make no reference to nullification; Maryland instructions (MI) which contain a reference to nullification; and radical nullification instructions (RNI) which are most explicit about the jury's nullification powers. Professionally performed audiotapes depicted criminal cases involving murder during a robbery, drunk driving involving vehicular homicide, and euthanasia (a nurse's mercy killing of a terminal cancer patient). All cases contained clear evidence of the defendant's guilt. Content analyses of jury deliberations indicate that RNI jurors spent less time on the evidence and more time discussing the nullification instructions than did MI and SPI juries. RNI juries also spent more time on relevant personal experiences, than did MI juries, who in turn, spent more time than did SPI juries. In the euthanasia case, RNI juries spent more time discussing the defendant's character than did the others, although this difference was not significant. Relative to MI and SPI juries, RNI juries gave higher verdict scores and fewer not-guilty outcomes in the drunk driving case and lower verdict scores and more not-guilty verdicts in the euthansia case. MI and SPI juries did not differ from each other in terms of verdicts given. No differences due to instruction were found for the murder case. Results indicate that nullifications can affect the functioning, and in some cases the verdicts, of juries. Three tables and 16 references are given.