Summit is played on a 4x4 grid, although larger boards are suggested as a variant. Players take turns writing numbers in empty spaces; each player will end up writing the numbers from 1-8. After all spaces are filled one player will score the rows and the other the columns; in each case the score is the absolute difference between the total and 18. Symmetric play is prohibited by a rule requiring no diagonal symmetry after both players have taken three turns.

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