Rättegångskostnader – Costs in Civil Procedure The rules on costs in Chapter 18 of the Swedish Code of Legal Procedure (Sw: Rättegångsbalken) have an impact on several procedural questions but have rarely been thoroughly discussed in legal practice or theory since their adoption in 1942. On the other hand, since the Code was adopted civil procecedure scholars have considerably focused on the development and changes in society and how they affect civil procedure. This thesis aims at examining both these lines of development. The impact of the theoretical discussions during the 20th century is critically addressed, with special attention to cost-related questions, and the application of rules on costs in some current and actual situations are examined and evaluated from a pragmatic perspective. The inquiry shows that costs have been of indirect relevance for the theoretical discussion in procedural law and that this theoretical development in turn has had effects on cost rules. Changing views on civil procedure have led to altered framings of cost problems and to shifts in how the rules have been comprehended and applied. The inquiry covers questions on cost assessment and cost shifting between the parties, as well as problems connected to possibilities to spread costs and risk on legal representatives, funders and others. It is argued that a more compromising and pluralistic application of the rules combined with more explicit communication in cost issues between the parties and the court during early stages of the proceedings may facilitate and lead to more nuanced cost decisions without burdening the final stages of the proceedings with extensive legal argumentation.