Tunnel Cards have six entry points, leading to tunnel segments (straight or curved) or dead ends. Shuffle them facedown into a 6x6 array around four faceup Scoring Cards, each showing dead ends valued two, three, or four.

Each turn, flip any free Tunnel Card faceup, and place a counter in your color on either a vacant faceup segment (anywhere) of an incomplete tunnel or on a facedown card to stop it from being flipped. Segments that reach such cards run straight through them. Play ceases when the last card is flipped. A completed tunnel between dead ends scores for the player with the most counters on its segments: Just multiply the sum of its dead ends by the number of segments. You must imagine the cards wrapped around a sphere; thus, tunnels continuing off edges can become very long! Most points wins. You'll really dig this game, along with its several variants.