If you own or are considering purchasing an AR-15-style rifle, understanding the legal landscape is just as important as understanding how the firearm operates. In several U.S. states, a regulatory concept known as the "one-feature" rule — sometimes called the "one evil feature" rule — determines whether your rifle is classified as an "assault weapon" under state law. Getting this wrong isn't just a technicality. Violations can result in felony charges, confiscation, and loss of your …