Juries are meant to decide based on the case before them in accordance with the laws as written. But jury discussions and motivations are sacrosanct, and you c

Juries are meant to decide based on the case before them in accordance with the laws as written. But jury discussions and motivations are sacrosanct, and you can't be punished for the "wrong" verdict. So technically you can ignore the law and vote how you like, allowing juries to effectively "nullify" a law by refusing to convict on it. But allowing a jury to ignore the law as written means they can convict or not based solely on political leaning, ethnicity, sexuality or religion etc. It's often cited as a way for society to oppose laws they disagree with, but is very much frowned upon by the legal system as it is easily exploited for very nefarious purposes and leads to a very unbalanced system rather than a consistent rule of law.