Steam: Map Expansion #4 brings Steam players to two new parts of the world. In South Africa, 3-6 players will need to focus on both mining and markets. The expansion based in Poland promises "Transitions from Broad to Standard Gauge." It includes two sets of rules: one for 3-4 players and another for 2 players. Steam: Map Expansion #4 also includes a new tile sheet for use with these game boards, as well as additional tiles for Steam: Map Expansion #3.