18SJ is a game in the 18xx-series set in the United Kingdoms of Sweden and Norway and pits two to six players as investors in railroad corporations in the formative years of Nordic railways. It features a simple mechanism for the nationalisation of public corporations and simulates the construction of the mainlines of Swedish rail. The nationalisation means that each game will be completed with a varying number of corporations ultimately available. Shareholders need to be careful in stock investment and the timing of train purchases to maximize personal profit.