Service of reply and defence to counterclaim
3.—(1) A plaintiff on whom a defendant serves a defence must serve a reply on that defendant if it is needed for compliance with rule 8, and if no reply is served, rule 14(1) will apply.
(2) A plaintiff on whom a defendant serves a counterclaim must, if he intends to defend it, serve on that defendant a defence to counterclaim.
(3) Where a plaintiff serves both a reply and a defence to counterclaim on any defendant, he must include them in the same document.
(4) A reply to any defence must be served by the plaintiff before the expiration of 21 days after the service on him of that defence, and a defence to counterclaim must be served by the plaintiff before the expiration of 21 days after the service on him of the counterclaim to which it relates.