The red mouse is in danger. Purple has two options to disrupt her path:
Place a curve pointing outwards. Red’s path now leads to the purple Nest, from which she may be used to bring cheese to the purple player.
Place a curve pointing inwards. A marble will then move past the red mouse and remove her from the Maze.
Be careful in the opening
Both the red and the purple mouse avoids getting too close to the dangers in their first turns.
Purple focuses on opening paths to her private and shared nests before approaching the Chamber.
Red focuses on removing the marbles without getting in their way.
Don't enter the Chamber with only one exit
The red mouse has moved to the Chamber and taken a cheese but neglected to secure a safe path back to her Nest.
Red places a black-white curve, hoping to continue to the red Nest on her next turn.
However, Purple replaces the black-white curve with a red-yellow cross. Red’s path to her Nest is suddenly replaced by a path to Purple’s Nest, something that will give Purple 1 point.
Look for cheese in the Maze
Both the blue and the purple mouse have found a cheese but failed to return to their Nests. Red could open a path to the Chamber with a cross but only has a curve. However, this gives here even better options.
A red-blue curve in front of Blue will lead Blue to Red's shared Nest in her turn, giving Red 1/2 point.
A red-blue curve in front of purple will lead Purple pass Red in her turn, not only giving Red the cheese but also a path to Red's private Nest, giving Red 1 point.
End the game with a path to the Chamber
All maze tiles are open and all players except Red replaced maze tiles the previous turn so they may not do so again. The game ends when Red has replaced a maze tile and all cheeses have been brought to the Nests.
Purple replaced a red-green cross in her last turn, giving her a path from her Nest to the Chamber.
However, Red replaces the red-yellow cross with a black-white curve, giving herself not only a path to her private Nest (a) but also to her shared Nest (b).
Red can now move between her Nests via the Chamber until all cheeses are gone!