The Mountaineer is a 3D tabletop board game in which players climb a mountain, completing special climbing routes and competing for climbing points. Multiple climbing routes and ten different mountain sides result in over twenty million game combinations.

Gameplay involves players rolling dice to determine weather and climbing conditions, trading with other players to obtain climbing gear, and selling the climbing gear to purchase special upgrades. Upgrades can increase climbing efficiency, change climbing conditions, sabotage other players, and even pay for helicopter flights to another place on the mountain. As players climb, they mark where they have been, resulting in the mountain displaying their trail and potentially blocking other players from climbing in that area.

The goal of the game is to finish all of the climbing routes and place as many route markers on the mountain as possible. This earns climbing points, with the player having the most climbing points winning the game.