In Durchmarsch, each player has a sheet of paper with four rows of numbers from 10 to 1. If you cross off all the numbers in a row, you win!
On your first turn, roll the eight dice, then see whether you can use two dice to sum to 10. If you can mark a 10, you either:
Set aside one die, and roll the remaining dice, hoping that two dice add up to a 9; if so, mark the 9 in the current row, then make this decision again for the 8, and so on. You never set aside more than three dice in total.
End your turn, passing all eight dice to the next player.
If you end your turn, on your next turn roll all eight dice and hope to mark off the leftmost unmarked number in your current row. To mark off 7-10, you need two dice that sum to this number; to mark off 1-6, you need one die that matches this number.
If you ever fail to mark off a number, mark the "misthrow" box at the end of the current row; next turn, roll the eight dice and hope to be able to mark the 10 in the next row down. If you have marked a misthrow in all four rows, start on the top row once again, trying to mark off the leftmost unmarked number. If you misthrow again in this row, mark through the row completely. If you mark through all four rows, you're out of the game.
If any player crosses off all the numbers in a row, they win. If no one manages to cross off an entire row during the course of the game, whoever remains in the game the longest wins.