There are three (3) different general categories of immunity.

Federally, pursuant to case law interpreting 42 U.S.C. § 1983, there are two (2) judicially created concepts of "absolute" and "qualified" immunity. Both of these concepts mean what they say and are available to individual actors, as opposed to entities.

Finally, there is something called "sovereign" immunity, which means that the "sovereign," e.g., the Federal or a State Government, cannot be sued by a private individual or entity without its permission. There are a variety of statutes existing which "waive" sovereign immunity in specific situations.

"Sovereign" immunity is absolute. The general concept is that the "sovereign" (the "king") cannot be sued, except to the extent the sovereign voluntarily subjects itself to suit. When this principle is applied to the States, pursuant to the 11^th Amendment of the Constitution, they are not subject to lawsuits for money damages in Federal Courts. So, typically, you cannot sue the State (or its departments or entities) in Federal Courts. However, you can still sue a State (or its departments or entities) "prospective relief" to curb unconstitutional policies, such as the school desegregation lawsuits, just not for money damages.

Because only the State itself is entitled t o sovereign immunity, you can still sue an individual state actor, unless the actor is considered to have the same protected legal status as the state, as a "state official." For example, elected officials, like a Governor, would be considered an alter ego for the "State" and could not be sued in Federal Court – again, an exception being to stop an unconstitutional practice. Sometimes, a state actor does not appear to be the equivalent of the State, but they are for sovereign immunity purposes; specifically, local Sheriffs may be considered a state official, although the law is extremely murky on this particular issue.

"Absolute" immunity is absolute or complete and you cannot sue a governmental actor protected by this form of immunity. Examples of governmental actors protected by this form of immunity include judges and prosecutors or actors that have a judicial role – legislators would be another example. This list is very limited; also, the immunity only extends to the actor’s activities "within the scope" of their official role or capacity. So, for instance, a judge who abuses his or her office to the detriment of some individual might step out aside of the judicial role in doing so, losing the cloak of absolute immunity.

"Qualified" immunity is a conditional form of immunity; most of the litigation we see involves qualified immunity. It involves a two (2) step process. A plaintiff, first, has to show that there was a violation of a "clearly established" constitutional right. There is quite a bit of litigation on what is a "clearly established" right and what is not. For instance, it is "clearly established" that a law enforcement cannot use excessive force during an arrest, as set forth by the protections of the 4^th and 14^th Amendments of the United States Constitution (similarly, the 8^th Amendment protects against excessive force used in the prison environment).

Assuming the plaintiff successfully shows a clearly established right was violated, the analysis shifts to the government actor who would try to demonstrate that he/she acted "objectively reasonable," as judged by the standard of an "objectively reasonable" actor. Thus, the "intent" of the official is generally irrelevant (intent IS relevant where there is an allegation that the official acted out of a specific discriminatory intent). The law can also be very fluid in this area.