如何玩紙上足球

Paper Soccer is a 2-player strategy game played on a 9x13 grid. A ball sits at the center, and each player tries to kick it into the opponent's goal.

Player 1 (Top) aims for the top goal. Player 2 (Bottom) aims for the bottom goal. The goals are openings in the top and bottom walls of the pitch.

On each turn, you draw a line from the ball's current position to an adjacent grid node in any of 8 directions (N, NE, E, SE, S, SW, W, NW). The ball moves along that line to the new node.

Each move draws a line segment from the ball to a neighboring node. You can move in any of 8 directions: up, down, left, right, and the 4 diagonals.

However, you cannot use the same edge twice. Once a line has been drawn between two nodes, that path is blocked for the rest of the game.

The pitch walls are also pre-drawn edges, so you cannot move through the walls (except through the goal openings).

Here Player 1 has moved the ball one step south from the center.

The key mechanic in Paper Soccer is the bounce. When the ball lands on a node that already has at least one used edge connected to it, the current player gets an extra move -- the ball "bounces" and continues moving.

This happens when landing on:

- A node touched by a previous move

- A wall node (which has boundary edges)

- Any node where edges already exist

Bounce chains can be very powerful, allowing a player to cover large distances in a single turn! Here the ball has bounced off a wall node.

You can chain multiple bounces in a row! Each time the ball lands on a node with existing edges, you get another move.

Skilled players plan bounce chains to move the ball many squares in a single turn, catching their opponent off guard.

The chain ends when the ball reaches a node with no existing edges (a "clean" node). Then the turn passes to the other player.

Planning your bounces while limiting your opponent's bounce opportunities is the core of Paper Soccer strategy.

If the ball reaches a position where all 8 possible edges from that node are used, the active player is stuck and loses the game!

This most often happens near walls and corners where boundary edges already take up several directions. When the ball is on a wall, half the directions may already be blocked.

Be careful not to move the ball into a dead end! Conversely, you can try to trap your opponent by forcing the ball toward nodes with many used edges.

Always look ahead to make sure you leave yourself (and deny your opponent) escape routes.

The goals are special nodes above and below the pitch. The top goal is at position (4, -1) and the bottom goal is at (4, 13).

To score, the ball must enter the goal from one of the goal mouth nodes. The goal mouth spans the top (or bottom) wall at x positions 3, 4, and 5. From these nodes, you can move the ball into the goal.

Player 1 (Top) tries to reach the top goal. Player 2 (Bottom) tries to reach the bottom goal.

Here the ball is near the top goal mouth, and Player 1 could score with a northward move from position (4, 0)!

Key strategies for Paper Soccer:

Control the center. Moves through the center of the pitch give you the most options. Avoid getting pushed to the edges where walls limit your moves.

Plan bounce chains. Look for sequences of moves that bounce through existing edges to cover large distances.

Limit opponent bounces. Try to leave clean nodes in your path so the ball stops and your turn ends at a favorable position.

Watch the goal mouths. Keep track of which edges near the goals have been used. An unblocked path to the goal can end the game instantly.

Think defensively. Sometimes the best move is one that denies your opponent a good bounce chain, even if it does not advance the ball toward your goal.