In "On the Underground: Paris/New York" players build the Paris Métro lines or the New York City Subway lines. Each player controls 2-4 different lines depending on the number of players.

During each turn, four destination cards are available that correspond to stations on the map. You can perform up to four actions; building rails by placing one of your track tokens on the board or taking a branch token. A player can use two branch tokens to branch off an existing line (whereas lines can normally only be expanded at the ends). After each player's turn, a passenger token is moved along the players' lines, using as little walking as possible, to reach one or two destinations determined at the start of the turn. Destination cards corresponding to the stations visited are then replaced with new cards, after which it is the next player's turn.