A capture in atomic chess. Nxg7 causes an "explosion" in which the capturing knight, captured pawn, and adjacent black rook and bishop are removed from play. Adjacent pawns are unaffected.

Atomic chess is a chess variant. Standard rules of chess apply, but all captures result in an "explosion" through which all surrounding white and black pieces other than pawns are removed from play. Some variations additionally remove rules concerning check such that the king may be able to move into or remain in check.


In 1995 the German Internet Chess Server (GICS) introduced the game, based on rules one of its users collected from friends who played offline.[1][2] It was soon after incorporated into the Middle East Wild Internet Server (MEWIS) and other smaller servers before being implemented at Chess Live and Internet Chess Club in 2000, Free Internet Chess Server in 2003 and Lichess in 2015.[3][4] It was added to Chess.com in late 2020. In 2021, 4.9 million atomic chess games were played on Lichess.[5] Lichess also hosts 24-hour tournaments called "Atomic Revolution" with cash prizes where 8 thousand people participated in the 2022 edition.[6]

It has garnered serious attention from chess grandmasters with Andrew Tang reaching quarterfinals and Jeffery Xiong reaching semifinals of Atomic Chess Championship 2017 hosted on Lichess, where both got knocked out by GM Arka50 who has won the championship in 2017, 2018 and 2020 whereas he did not participate in 2019 and 2021 editions.[7]

Rules and variations

Rules of atomic chess are the same as standard chess with a few important differences concerning capturing, check, and winning conditions.


In a capture in standard chess, the captured piece is removed from the board, and the capturing piece takes its place. In atomic chess, a capture causes an "explosion" through which both pieces are removed from the board as well as all non-pawn pieces in the eight squares immediately surrounding the capture. Pawns are removed only when capturing, captured directly, or promoted. In case of en passant, the explosion occurs on the square to which the capturing pawn would have moved. Captures that result in the explosion of a player's own king are illegal; therefore, a king can never capture.[8][9]


Black to move: Win or stalemate?
a8 black king
b7 white rook
c4 white king
With Black to move, this position would be a stalemate in variations of atomic chess that do not allow a king to move into check, but a win for White in variations that do not enforce the rules of check. In no version of the game would it be legal for the king to take the rook.

Threats to the king can be direct or indirect. Putting a king in check is a direct attack and is sometimes called "atomic check".[10] An indirect threat occurs when a player threatens to explode the king by capturing an adjacent piece. In most variations of atomic chess, players must respond to being checked in a similar way they would in traditional chess—by moving the king out of check, blocking the check, or removing the checking piece—but an exception exists when the checked player can win the game by exploding the checking player's king.

As the king cannot take another piece, it is possible to move the kings next to each other without a check occurring or to escape check. This possibility is often used by a losing player to defensively position his king next to his opponent's at endgame, hoping for a draw. Depending on the board setup, this strategy is sometimes optimal and allows the draw to be forced. At other times, a player can counter by forcing a win with a position such that a piece or pawn can be exploded next to their opponent's king without blowing up their own king, or they can force the opposing king away using their king and the remaining pieces on the board, which will typically result in a loss for the retreating king.

The variant of atomic chess played at the Internet Chess Club is one that does not enforce check at all, making legal any move, even one leaving the king to be captured directly in the next move.[9][11]

Winning conditions

In all variations of atomic chess, a player wins by exploding the king of the opposite color without exploding their own king. This is usually done by capturing a piece on a square adjacent to the opponent's king or putting a queen next to the king which results in checkmate since a king cannot take any piece.

In variations that require a response to being checked, it is possible to checkmate an opponent to win the game, creating a situation in which a king is directly threatened and cannot make a legal move. This is sometimes called "atomic checkmate".[10] It is likewise possible for the game to end in stalemate if a king is not directly threatened and no legal moves are possible.

When typical rules of check are not enforced, victory is only attained via the explosion of the enemy king. In these variations without check, the king may be forced into check and thus capture through zugzwang.


The first-move advantage enjoyed by White is much greater in this game than in standard chess. However, no attempts to prove a win for White have been successful.

Material sacrifices are more common in atomic chess than in chess. In the opening and middlegame, it is common to offer a piece in order to open spaces to seize an initiative.[9]


A common opening trap
a8 black rook
b8 black knight
c8 black bishop
d8 black queen
e8 black king
f8 black bishop
g8 black knight
h8 black rook
a7 black pawn
b7 black pawn
c7 black pawn
e7 black pawn
f7 black pawn
g7 black pawn
h7 black pawn
d5 black pawn
e5 white knight
a2 white pawn
b2 white pawn
c2 white pawn
d2 white pawn
e2 white pawn
f2 white pawn
g2 white pawn
h2 white pawn
a1 white rook
b1 white knight
c1 white bishop
d1 white queen
e1 white king
f1 white bishop
h1 white rook
A common response to 1.Nf3 in chess is 1...d5. In atomic chess this leads to a forced loss after 2.Ne5, threatening Nxf7. After either 2...f6 or 2...f5 White can play 3.Nd7. White's knight cannot be taken by any piece because of its proximity to Black's king, and Black cannot stop 4.Nxf8.

White has the initiative in atomic chess, and many openings begin with a quick attempt to explode Black's d-, e-, or f-pawns.[12] For this reason, atomic openings are fraught with traps, and Black may have to respond precisely to defend. Several common traps begin with 1.Nf3 followed by Ng5 or Ne5, forcing Black to start with 1..f6 to maintain rough equality.[2] Games between experienced players follow more traditional opening principles, such as piece development, controlling space, and winning material.[12]


An endgame position
b6 white queen
a5 black pawn
a4 white pawn
c3 white king
d3 black king
Black has connected kings and become immune to check. However, White can win by forcing the black king to be adjacent to the black pawn and then capturing the pawn.
1.Kc4 Kd4 2.Kb5+ Kc5 3.Ka6+ Kb5 4.Ka7+ Ka6 5.Qxa5#

Black is forced to retain the connection, or the queen will chase the king and deliver mate.

As with atomic opening theory, a small amount of endgame theory and analyses have been published online by strong players.[13]

A common scenario in atomic endgames is to have two kings on adjacent squares. As a player cannot intentionally blow up their own king, a king can never capture another piece, including another king. Similarly, because a capture affects all adjacent squares, one king cannot be captured directly if it means destruction of the other. Moving one king towards the other is thus a strategy to achieve a draw. The player with the advantage must then maneuver into a position where a non-king piece can be captured that is adjacent to one king but not the other. If there is no piece that can be captured, the player with the advantage can promote two queens and force the opponent into zugzwang and therefore forcing the opponent's king away from their king. Creative use of zugzwang is a common tactic to force a win in these situations.[14]

The Internet Chess Club variation of atomic chess ignores check completely, and thus leads to different outcomes in certain situations. For example, a king and rook vs. king endgame that would be a draw under normal circumstances can become a forced win on ICC.

See also

Other chess variants based on explosions:


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  2. ^ a b "Vlasov's Atomic-Chess Homepage". Archived from the original on 25 March 2014. Retrieved 24 May 2014.
  3. ^ Long, Nick. "Atomic Chess". Chronatog.com. Archived from the original on 12 June 2020. Retrieved 12 June 2020.
  4. ^ "Atomic Chess! And more". lichess.org. Archived from the original on 2018-08-18. Retrieved 2017-11-08.
  5. ^ "Lichess Variants Database".
  6. ^ "Lichess Variant Revolutions 2022".
  8. ^ "Atomic rules". Free Internet Chess Server website. freechess.org. 27 February 2008. Archived from the original on 25 May 2014. Retrieved 24 May 2014.
  9. ^ a b c Seymour, Tim (2009). "Atomic Chess: Rules". Atomic Chess (archived copy). Chronatog.com. Archived from the original on 12 June 2020. Retrieved 12 June 2020.
  10. ^ a b Blackburn, Leonard. "The Rules of Atomic Chess" (PDF). Parkland College. Archived from the original (PDF) on 25 May 2014. Retrieved 25 May 2014.
  11. ^ "ICC Help: atomic". chessclub.com. The Internet Chess Club. Archived from the original on 25 May 2014. Retrieved 24 May 2014.
  12. ^ a b Krakov, Sergey. "Atomic chess openings". Siggemannen's Atomic Chess Page (archived copy). chronatog.com. Archived from the original on 12 June 2020. Retrieved 12 June 2020.
  13. ^ "Atomic Land". 2005. Archived from the original on 13 May 2013. Retrieved 24 May 2014.
  14. ^ "On Joined Kings". Atomic Land. 2005. Archived from the original on 4 March 2016. Retrieved 24 May 2014.