Suicide capability is one of few risk factors associated with suicide attempts among ideators. In the decade since the Interpersonal Psychological Theory of Suicide introduced the concept of acquired capability (i.e. the ability to face the fear and pain associated with death), understanding of the capability to attempt suicide has grown. Acquired (e.g. NSSI), dispositional (e.g. genetic), and practical contributors (e.g. access to firearms) appear to influence suicide capability via mechanisms such as the fear of death, persistence through pain, and familiarity with suicide methods. Self-report methods have shown mixed results, highlighting the importance of developing behavioral measures of suicide capability.