The strength of connections typically governs the cross-sectional size of structural timber members. This is particularly true when multiple slotted-in plates and dowels are used. In such a case, in fact, the larger the number of slotted-in plates - which practically means "the wider the cross section" - the higher the capacity per dowel will be. However, in the case of several slotted-in plates, due to inevitable fabrication tolerances the plates of the connection could be unevenly loaded. It is very important, therefore, to choose a layout of the connection that allows for a ductile behaviour and thus for a possible load redistribution among the dowels and ultimately contribute to the overall robustness of the structure. The present paper deals with the results of an investigation conducted on dowel-type connections with multiple slottedin steel plates. A large set of laboratory tests were carried out at the Division of Structural Engineering, Lund University, Sweden. The tests were conducted by varying two different parameters, i.e. the number of slotted-in steel plates and the thickness of the timber elements. The objectives were 1) to assess the influence of these parameters on the performance of the timber joints in terms of load-bearing capacity, stiffness, and ductility; and 2) to provide design guidance in order to prevent premature (brittle) failure of the connection.