Collinear-Equidistant Gomoku (5 in an AP) | 五子等距共线棋

Welcome to a new variety of Gomoku! Here are the rules and some thoughts.

Basic rule

If you have played Gomoku (5-in-a-Row), the rule is easy:

Instead of having 5 adjacent pieces in a row, now you can win with any 5 pieces that are collinear and equidistant.

This will include all Gomoku's winning configurations, but add a lot more, like this:

In other words, you win if 5 of your pieces form an arithmetic progression, or AP, in the 2D metric.

(If you never played 5-in-a-Row, tic-tac-toe is "3-in-a-Row". Our gameboard will be much larger.)

A small exercise

Prove that when there are only 2 players, Player 1 can win in merely six steps.

... which is why it's reasonable to have at least 3 players. In fact, that's how it was initially played after introduced by one of my classmates (should be Shengyu Zhao).

Joining the game

Click "Join".

Game play

In your turn, click an empty spot on the board to put down a piece.

Force-end a turn

Like many games, once in a while, someone will disconnect, producing an understandably long turn.

To deal with this, most games use a clock to time the turns and end the turn when the time is up. But this game is usually played between friends who just want to relax. We don't want to rush them.

To account for both patience and fairness,

turns are never interrupted by the system, but if a turn exceeds 60s, every player has an option to force-end the turn (including the current player, who would be altruistic to do that).

The rigor is in your hands.

Clear-out

10 minutes after the last move or immediately after a winner is annouced, everyone visiting the page could clear the board.

Todo

Acknowledgements

(Another interesting chess)

Wish you a 5 in an AP!