In the United States, qualified immunity is a legal principle that grants government officials performing discretionary (optional) functions immunity from civil suits unless the plaintiff shows that the official violated "clearly established statutory or constitutional rights of which a reasonable person would have known". It is a form of sovereign immunity less strict than absolute immunity that is intended to protect officials who "make reasonable but mistaken judgments about open legal questions", extending to "all [officials] but the plainly incompetent or those who knowingly violate the law". Qualified immunity applies only to government officials in civil litigation, and does not protect the government itself from suits arising from officials' actions.