Self-Defense is a right most people except extreme Pacifists accept. The law in the United Kingdom, the United States of America and Australia allow use of reasonable force to defend oneself, defend other people and property. In practice what's reasonable can sometimes be hard to determine and varies between jurisdictions. Bias by judges and juries can affect the outcome of trials. Notably in The South of the USA White People can get away with more force against Black people than Black people can use against whites.