1. necessity：在传统的英美刑法理论上,并不区分正当化(justification)与免责(excuse),在借鉴大陆法系刑法理论的基础上,弗莱彻教授指出,与紧急避险(necessity)、同意(consent)等抗辩事由一样,自卫的作用在于使一个通常违法的行为合法化.
2. act of rescue; necessity：防卫过当 unjustifiable self-defense | 紧急避险 act of rescue; necessity | 犯罪既遂 completion of a crime
3. Act of rescue：救援模型:Rescue Model | 紧急避险:Act of rescue | 企业拯救:Enterprise rescue