Country road is a Nikoli puzzle in which the aim of the game is to draw a single, closed loop through all the rooms on the grid. The game could be played on any sized grid, as long as the rules below are followed of course.
The rules are as follows:
- Draw a single, closed loop within the grid.
- The loop must go through each room.
- Each room can only be entered and exited once.
- When there's a number in the room the loop must connect that many cells within that room. If a room doesn't have a number it can have any number of cells connected by the loop.
- Cells which are not connected via the loop can only be adjacent to each other if they are in the same room. If they're in a different room they can only be connected diagonally (corners touch), not orthogonally (sides touch).
Country Road is usually not too difficult to figure out, but it does depend heavily on the size of the puzzle. It's often easiest to start with rooms that are connected to only 2 other rooms, as it means the exit and entrance are clear. Rooms with a number are often helpful as well, especially if the number is equal to the total number of cells in that room.
Sometimes a diagonally adjacent cell will become impassable due to the last rule, marking those can help with figuring out the puzzle as well.
The Country Road puzzle can be a bit trickier to adapt to an RPG setting compared to other Nikoli puzzles. The simplest adaptation is to use the loop as a path you can follow within a closed system or a path some kind of entity follows. For example, a security droid might follow the same path over and over again, the empty map with the numbers could be given to the players to allow them to either hide from this droid or to block its path.
In the example below my character is trapped in a building with 8 rooms. There are 3 portals within this building, but only 1 will take her out of that building, the other 2 are traps.
She's been given the numbers on the map and the instructions on solving the Country Road puzzle. All she has to do is step into the portal that is connected to the loop, if she tries to take a different portal she will face the consequences of the trap.
Country Road can be adapted in all sorts of ways, but they're not always all that obvious. I've mentioned a few of them so far, but there's plenty more that could be done with it. The loop could show a path outside of the view of security cameras, a ley line within a town or maze, the flow of a river or underwater currents, and so on.