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Question about Base Game Roads - Is a chain of individual road pieces that goes all around a terrain hex a closed continuous road?

Answer

A continuous road is considered closed if it connects two of your settlements and/or cities with each other or if it connects one of your settlements or cities with one of your units (knights). You are not allowed to remove a road segment from a closed road.

Special case: If a continuous road starts at a settlement or city and leads back to this settlement or city without its individual road segments having passed an intersection on which something has been built, then one of the two ends of the continuous road adjacent to the settlement or city is considered open. Consequently, any one of the two road segments adjacent to the settlement or city may be moved or removed by playing a card (for example, the “Diplomat” card in Cities & Knights).

Accordingly, the following applies to ships:
A shipping route is considered closed if it connects two of your settlements and/or cities with each other or if it connects one of your settlements or cities with one of your units (knights). You are not allowed to move or remove a ship from a closed shipping route.

Special case: If a shipping route starts at a settlement or city and leads back to this settlement or city without its individual ships having passed an intersection on which something has been built, then one of the two ends of the shipping route adjacent to the settlement or city is considered open. Consequently, any one of the two ships adjacent to the settlement or city may be moved or removed.