Pleading patent infringement got a little bit trickier on December 1, 2015.

Prior to that date, a patentee could plead a claim of direct infringement by using the model complaint laid out in Form 18 of the Federal Rules of Civil Procedure. Rule 84 indicated that the Forms contained in the Appendix of Forms were sufficient under the Rules.

That changed on December 1, when several changes to the Rules went into effect. One of the changes was to abrogate Rule 84 and the Appendix of Forms. Thus, Form 18 no longer exists.

Without Form 18, patentees will need to pass the higher Twombley/Iqbalthreshold for pleading direct infringement. The Twombley/Iqbal line of cases requires that a plaintiff assert sufficient factual allegations that, if taken as true, state a claim that is plausible on its face.

Facing this higher bar, patentees will almost certainly need to include more factual support in a patent infringement complaint than what was required by Form 18. But how much more? Will patentees be required to identify which patent claims they are asserting? Will courts require patentees to include an infringement claim chart with patent infringement complaints?