Qualified immunity is a legal principle in the United States that grants government officials performing discretionary functions immunity from lawsuits for damages unless they violate "clearly established statutory or constitutional rights of which reasonable person would have known". Here are some key points about qualified immunity:

• Qualified immunity is a type of legal immunity that protects government officials from lawsuits alleging that they violated a plaintiffs rights.

• It only allows suits where officials violated a “clearly established” statutory or constitutional right.

• Qualified immunity is not immunity from having to pay money damages, but rather immunity from having to go through the costs of a trial at all.

• Courts must resolve qualified immunity issues as early in a case as possible, preferably before discovery.

• Qualified immunity only applies to suits against government officials as individuals, not suits against the government for damages caused by the officials’ actions.

• Although qualified immunity frequently appears in cases involving police officers, it also applies to most other executive branch officials.

• Judges, prosecutors, legislators, and some other government officials do not receive qualified immunity, but most are protected by other immunity doctrines.

• Qualified immunity is a doctrine of federal law, not affected by changes in state law.

• Some states have passed what they deem to be modifications of qualified immunity in the context of state law claims, but these changes do not impact the doctrine of qualified immunity as applied to federal constitutional law.

• Critics argue that qualified immunity creates an arbitrary standard that stifles the rule of law and operates in a way divorced from actual reality.

• Some argue that qualified immunity is ineffective for its stated goals in such a way that it could not be strengthened, and should be replaced by other mechanisms for obtaining those ends.

In summary, qualified immunity is a legal principle that protects government officials from lawsuits alleging that they violated a plaintiffs rights, but only allows suits where officials violated a “clearly established” statutory or constitutional right. It is not immunity from having to pay money damages, but rather immunity from having to go through the costs of a trial at all. Critics argue that qualified immunity creates an arbitrary standard that stifles the rule of law and operates in a way divorced from actual reality.