Appellant was denied a fair trial by the admission, without a limiting instruction, of incriminating post-arrest statements made by his codefendant. Although Sauza forfeited the issue by not raising it and requesting a limiting instruction at trial, review is available for plain error. Because the codefendant was available, explicitly denied having made the statements in question, and provided testimony that was favorable to Sauza’s defense, there was no denial of Sauza’s rights. However, because the codefendant’s statements were admissible, the trial court was then obligated to give the jury a limiting instruction so that there would be no prejudicial “spillover.” Sauza’s substantial rights were affected by the court’s error because the evidence was not overwhelming, and the government strongly argued the statements to the jury. Furthermore, the government had promised a limiting instruction when it moved to admit the statements, and then failed to offer one, compounding the court’s error and defense counsel’s omission. Because the fairness and integrity of the trial were substantially affected, reversal was required.