This document outlines several precedents related to manslaughter cases in UK law. It discusses precedents establishing: 1) Constructive manslaughter requires an unlawful act that a reasonable person would recognize poses a risk of harm. 2) Gross negligence manslaughter is based on ordinary negligence rules, and it is for the jury to decide if the defendant's actions amounted to gross negligence worthy of criminal punishment. 3) Manslaughter is difficult to define, but recklessness can be used to instruct juries, and there is a difference between unlawful and lawful but careless acts. 4) Juries can be instructed on recklessness and subjective recklessness may be enough for manslaughter. Vague definitions are needed for juries in