Span is a monochrome pencil-and-paper strategy game for two players. The objective is to connect your two goal points before your opponent does likewise.

The board for Span is a 7x7 or 9x9 grid; graph paper works well. The game is played on intersections and edges of the grid. Draw an open circle at the center of each edge of the board; these are the four goal points. One player is Horizontal, trying to connect the left goal point to the right goal point; the other player is Vertical, connecting the top and bottom goal points.

On your turn, you may do one of the following:

• Draw a single-unit line between two adjacent open intersections, or
• Add a node (a large, solid dot) to an intersection without a node.

A point is open if it

• Has no node and touches fewer than two line segments, or
• Has a node and touches fewer than three line segments.

Note that both players can connect their goal points to either player's line segments; every line segment on the board is fair. Thus, the game is "monochrome" - the only elements on the board "owned" by either player are the goal points.

If you connect your own goal points via a connected chain of edges, you win. If either player connects all four goal points at once, the game is a draw.