MAST BUY is an auction game where the players are athletes in a yacht race and must purchase the masts they will use.
The "masts" in the game consist of a set of small wooden dowels between 120mm and 160mm in 5 mm increments, with multiple of each size. Each player starts the game with 50 money, marked on a board, a random mast, and a blue stone.
On a turn, a player chooses a mast, blindly, from the game box to put up for auction. The auction proceeds around the table with each player making a pass or bidding and the last player to place a bid winning the mast.
The game ends when a player has won a certain number of masts, four of the same size, or is out of money.
If a player has collected four of the same size, they immediately win. Otherwise, players earn points for the number of masts they have in sequential size order (5 mm apart), with duplicates of a size adding no additional points. Players also earn points for money that they did not spend. The player with the most points wins.