This guide sets out the law governing the immigration consequences of criminal convictions. It begins with the structural distinction between inadmissibility and deportability and explains why the same conviction produces different results depending on whether a person is applying for admission or defending against removal. It then defines conviction and sentence as immigration law uses those terms, which is more broadly than most state law does. Central parts treat the aggravated felony definition category by category, crimes involving moral turpitude and their counting rules, controlled substance offenses, firearms and domestic violence grounds, and the conduct-based grounds that require no conviction at all. A full part addresses the categorical and modified categorical approaches, divisibility, and the record of conviction. Later parts cover relief from removal, detention consequences, naturalization and good moral character, plea negotiation strategy, post-conviction relief, and judicial review.