Alternative pleading permits a party in a court action to argue multiple possibilities that may be mutually exclusive by making use of legal fiction.
A legal fiction in which a party to a lawsuit or a defendant charged with a crime can plead two ways which are inconsistent with each other. Examples:
a) someone hurt in an accident can plead that the other party was negligent or ran into him intentionally.
b) "not guilty" and "not guilty by reason of insanity" (in which there is the implied admission that the defendant committed the act).