This chapter is concerned with the jurisdictional problems caused by the existence of multiple parties or multiple claims in the same proceedings. Article 8 of Brussels 2012 and Article 6 of Lugano 2007 deal with these matters. These provisions focus on special jurisdiction in that they apply only where a defendant domiciled in one Member State is sued in another Member State. The discussions cover rules on multiple claimants, multiple defendants, third-party proceedings, multiple claims, counterclaims, set-off, and claims relating to contract and immovable property. These rules are all subject to an exception where the courts of another Member State have exclusive jurisdiction under an exclusive choice-of-court agreement or under Brussels 2012, Article 24 (Lugano 2007, Article 22). There are also exceptions in the case of protective jurisdiction (Brussels 2012, Articles 10–22 and Lugano 2007, Articles 8–21.