If you were asked: 'What are the most important things we know about addiction?' what would you say? This paper brings together a body of knowledge across multiple domains and arranged as a list of 10 things known about addiction, as a response to such a question. The 10 things are: (1) addiction is fundamentally about compulsive behaviour; (2) compulsive drug seeking is initiated outside of consciousness; (3) addiction is about 50% heritable and complexity abounds; (4) most people with addictions who present for help have other psychiatric problems as well; (5) addiction is a chronic relapsing disorder in the majority of people who present for help; (6) different psychotherapies appear to produce similar treatment outcomes; (7) 'come back when you're motivated' is no longer an acceptable therapeutic response; (8) the more individualized and broad-based the treatment a person with addiction receives, the better the outcome; (9) epiphanies are hard to manufacture; and (10) change takes time. The paper concludes with a call for unity between warring factions in the field to use the knowledge already known more effectively for the betterment of tangata whaiora (patients) suffering from addictive disorders.