The essence of the game in Tetris is that random figures (each of which consists strictly of 4 segments) fall from top to bottom on the field. During the flight of each figure, the player can rotate it around its axis and move it left and right horizontally, choosing the place where it should fall. When a line is filled horizontally it disappears. Points are awarded for each line that disappears. The speed of falling of each subsequent figure increases with the new level. The game ends when the new figure can no longer fit into the field parameters and then the total points scored for the game are calculated.