As long as this gulf exists, true harmonization in antitrust cannot be achieved. Under the Federal Rules of Civil Procedure, a plaintiff's complaint is legally sufficient if it puts the defendant on notice of the range of issues at stake in the action. The function of the pleadings is to give the adversary a fair opportunity to prove a case at trial. In European courts, pleadings emphasize factual allegations, issue formulation and proof at trial. US courts, even in antitrust cases, will permit cases to go forward on the basis of bare-bones pleadings.
European courts require much more detail.
It was first adopted in the US as part of the 1912 Equity Rules. When the Federal Rules of Civil Procedure were adopted in 1938, discovery was a key ingredient. Discovery is intimately related to the concept of notice pleading. The drafters of the Federal Rules believed that historically pleadings had played too large a role in federal litigation. In their view, the essential function of pleadings was simply to put the adversary on notice of the claims and defenses at issue.