peer2peergames

Four Connect

Drop a disc, make a line of four. Simple enough to teach in a sentence, and solved thoroughly enough that the first player wins outright with perfect play.

Play Four Connect Leaderboard

The rules

  1. The grid stands upright, seven columns wide and six rows deep, so there are forty-two slots in all.
  2. On your turn, drop one disc into any column that is not already full.
  3. The disc falls to the lowest free slot in that column. You choose the column; gravity chooses the row.
  4. Four of your discs in an unbroken line wins: along a row, up a column, or on either diagonal.
  5. A column with six discs in it is full and cannot be played.

How a game ends

  1. A line of four wins immediately, and the rest of the grid does not matter.
  2. If all forty-two slots fill with neither player making a line, the game is a draw.
  3. A resignation or a missed deadline ends the game against that player.

Worth knowing before you start

  1. Four Connect has been solved: with perfect play from both sides, the player who goes first wins.
  2. The winning first move is the middle column. Every other opening move can be answered to at least a draw.
  3. Going first is therefore a real advantage rather than a formality, which is why the seed decides it and publishes how.

The seed decides who plays red and goes first, and is published when the game ends so the choice can be checked afterwards.

Playing it here

  • Against a person or the bot. The bot needs no account and starts at once. To play a person, be rated and keep your games, you need an account: an email address and a password.
  • At your own pace. Every move has a deadline you both see, from one minute to a week. A game can take an evening or it can take a fortnight.
  • Nothing to buy and nothing to win. No stakes, no prizes, no boosts, no undo. The only thing on offer is a place on a leaderboard, and only if you want one.
  • Every game can be checked. Anything decided by chance comes from the game's seed, and the seed is published the moment the game ends, so any finished game can be replayed and verified by anyone. See fair play.