In Shotzee each player has a score sheet with four 3x3 grids. On a turn, a player rolls from 1-4 dice (their choice) and then all players must enter the number rolled in an empty space in one of their grids.
After all the grids are full they are scored. Players score for columns in which the first two numbers add up to the third, rows in which the second number subtracted from the first equals the third, and long diagonals in which the first two numbers multiplied together equal the third.
Bonus points are given for combinations where the result (third number) is particularly high, for having multiple additions or subtractions score in one grid, and for "Shotzees," which are multiplications where the result is 21.
As a variant, on each die roll each player must write the number in one box in each of their grids.