Can a plaintiff choose to file an amended complaint?

Should plaintiff choose to file an amended complaint, she is informed that the court cannot refer to a prior pleading in order to make plaintiff's amended complaint complete. Local Rule 220 requires that an amended complaint be complete in itself without reference to any prior pleading. This is because, as a general rule, an amended complaint supersedes the original complaint. See Loux v. Rhay, 375 F.2d 55, 57 (9th Cir. 1967). Once plaintiff files an amended complaint, the original pleading no longer serves any function in the case. Therefore, in an amended complaint, as in an original complaint, each claim and the involvement of each defendant must be sufficiently alleged.