The Castles of Burgundy: Trade Routes is a small expansion for The Castles of Burgundy included in the Notre Dame: 10th Anniversary game and possibly available separately.
Each player receives a number of cards depending on the number of players. If there are 2 players, each receives 5 “Trading Routes”; with 3 players, each receives 4; and with 4 players, each receives 3. These cards are placed face up side by side above the player board, forming a trading route.
Whenever players sell their goods (which must still be all the goods of one kind), they do not place those tiles on the corresponding space on their player board, but on their “Trading Routes” cards, filling the display spaces from left to right. If the color of a space matches the color of a tile when it’s placed on a display space, then the player receives immediately the bonus shown on that space.
For more information, visit the BGG listing.