Four Player Chess (4PC) is an exciting chess variant that can be played in two main modes: Teams and Free-for-All (FFA). Here is an overview of the rules for each mode, along with some additional notes on Solo and Variant games.

Teams

Guidelines	Details
Gameplay order	The game begins with the Red player, and moves proceed clockwise in the order: Red, Blue, Yellow, Green.
Teammates	Your teammate is the player directly across from you on the board. You cannot capture your teammate's pieces.
Pawn promotion	Pawns promote on your 11th rank.
Checkmate and stalemate	Checkmate occurs only when the checkmated player's turn is reached. The first team to checkmate an enemy player wins. Stalemate results in a draw.
Resignation and timeout	A player who resigns or times out on their first move will lose rating points, and the game will be aborted. A disconnected player has 60 seconds to reconnect before being forfeited on time.
Arrows and communication	Use right-click + drag to draw arrows, which are visible to your teammate. You can see their arrows as well. Click anywhere on the board to clear all arrows or Shift + click to clear only your own.

Check out this forum post to learn strategies for teams: Strategy tips for teams

Free-for-All (FFA)

These rules do not apply to Diplomacy Games. Check out this forum post to learn about this variant: Four Player Diplomacy Variant.

Guidelines	Details
Objective	The goal is to finish with the most points of any player.
Points system	Checkmating an opponent: +20 points Stalemating yourself +20 Capturing active (colored) pieces: Pawns +1, 1-point Queens +1 Knights +3, Bishops +5, Rooks +5, Queens +9, Kings +20, Spare kings +3 Checking two players simultaneously: with a Queen: +1, otherwise +5 Checking three players simultaneously: with a Queen: +5, otherwise +20
Pawn promotion	Pawns promote on your 8th rank.
Elimination and dead pieces	Pieces become 'dead' (grey) when a player is eliminated. Capturing dead pieces does not earn points.
Game conclusion	The game ends when three players are eliminated. When a player resigns or times out, their army becomes 'dead,' but their King remains 'live' and moves randomly until checkmated or stalemated. Points for stalemated resigned kings are shared. The last remaining player receives +20 (or 40) points for each live king (except their own) left on the board. In cases of insufficient material, threefold repetition, or the 50-move rule, remaining players receive +10 points each. Total points do not directly affect rating calculations; only final placement does.
Disconnection and resignation	A disconnected player has 60 seconds to reconnect before being forfeited on time. If a resign or timeout occurs before all players have made at least three moves, the game will be aborted, and the resigning player loses rating points.
Prohibited actions	Players must think independently and cannot coordinate moves or attacks using chat during FFA games. Players may not discuss blunders that can be fixed but may discuss what already happened and cannot be undone. Examples of prohibited phrases include: 'Check red,' 'Let's attack green together,' and 'Resign!' It is also prohibited to ask other players to give you points.

Check out this forum post to learn tips for beginners: Beginner tips and fundamentals.

Solo

Solo games are Free-for-All games rated as winner-takes-all (WTA), meaning only the winner gains (Solo) rating, and the second through fourth place lose equally.

Variants

Variant games can be Solo, FFA, or Teams. The specific rules for the game are displayed above the board when clicking on the icon after selecting a variant: