AT common law, in cases where the substantive claim is governed by foreign law, questions of procedure are nonetheless governed by the lex fori. In the context of damages, although the existence of damage is a question for the lex causae, its quantification and assessment is determined according to the law of the forum (Boys v Chaplin [1971] A.C. 356). The distinction between substance and procedure is preserved by Article 1(3) of Council Regulation (EC) No 864/2007 (“Rome II”) which provides, with certain exceptions, that Rome II “shall not apply to evidence and procedure”. That rule is, however, qualified by Article 15, which requires the law applicable under the Regulation (i.e. “the law applicable to non-contractual obligations”) to govern, inter alia, “the existence, the nature and the assessment of damage or the remedy claimed” (Article 15(c)). The decision of the Court of Appeal in Wall v Mutuelle De Poitiers Assurances [2014] EWCA Civ 138; [2014] 3 All E.R. 340 concerns the definition of “procedure” in Article 1(3) and the meaning of “applicable law” in Article 15(c). It raises the important question of how far Rome II has encroached on the traditional view of national procedural autonomy in the conflict of laws.