The Chess Variant Pages


by Scarmani



FreeChess is a chess variant that borrows ideas from several other chess variants, and has a few unique concepts of its own.  The underlying idea is to dissociate movement-abilities from physical pieces, and to allow these "attributes" to be placed onto the board at will, added to and subtracted from each other, separated from one another, or even removed from the board and returned to a player's "attribute reserve".  The opening setup is an empty board, allowing players to create their own opening setup.  Thus, the players have been freed to pursue their dynamic tactical visions as far as possible: they are no longer limited by discrete, sluggish pieces that can only disappear from the board.  Rule-dictated restrictions are retained only where necessary to keep the game sharp, well-defined and decisively winnable.  Freechess was invented by Scarmani in 2003.


The initial board is an empty, 13x13 square board.  Each player has an "attribute reserve", consisting of 13 opawn-attributes, 8 knight-attributes, 5 bishop-attributes, 3 rook-attributes, 2 "combinator" attributes and 1 royal attribute.  

* An opawn (omni directional pawn) attribute confers the ability to move one or two squares orthogonally in any direction and to capture one square diagonally in any direction.  There is no unidirectionality; thus no en passant, no pawn promotion, nor any restrictions on placement locations.
* A knight attribute confers the ability to move and capture as a knight.
* A bishop attribute confers the ability to move and capture as a bishop.
* A rook attribute confers the ability to move and capture as a rook.
* A combinator attribute confers the ability for a piece's attributes to be used in parallel during a turn, rather than singly.  In a sense, it could be called the "progressive" attribute:  as an example, a knight-bishop (aka cardinal) may move only either as a bishop or a knight in a single turn.  Contrastingly, a cardinal-combinator in a single turn may make a knight move, a bishop move, a knight move followed by a bishop move, or a bishop move followed by a knight move(!).  Clearly, a combinator piece is potentially very powerful - for example it may make multiple captures on a single turn.  There are some subtleties involved with combinator moves that will be discussed below.
* A royal attribute confers the ability to move one square orthogonally or diagonally in any direction.  A royal piece must move out of or otherwise evade check if possible; the owner of the royal piece loses the game if the royal piece is mated.  The royal piece can only capture using king moves.  There is no castling, as there is no fixed initial setup, because the king can be combined with other pieces (through friendly capture or attribute placement) to gain new movement abilities, and most of all because FreeChess is intended to be an attacking, tactical game

Note: this game can be played by using 4 conventional chess sets and an oversized board, with a combinator attribute indicated by an upsidedown rook.  Combination pieces can be indicated by placing several conventional chess pieces on the same square.


Players take turns doing one and only one of the following: 1) Placing an attribute on the board, 2) Moving a piece, 3) Splitting up a piece, or 4) Resigning.  A player may also offer a draw at the close of his or her turn, assuming it consisted of 1), 2) or 3).

1) Placing an attribute on the board:  An attribute may only be placed onto a "valid" square.  Initially, the entire board is considered "valid."  However, once there is at least one piece of each color on the board, valid squares are restricted to those squares that are either occupied by, or reachable by, or attacked by, a piece on the board.  An attribute may be placed onto A) an empty square, B) a square occupied by a friendly piece, or C) a square occupied by an enemy piece possessing the identical attribute.
    A) An attribute placed onto an empty square becomes a piece.  Thus, an opawn attribute becomes an opawn, a knight attribute becomes a knight, a bishop attribute becomes a bishop, a rook attribute becomes a rook, and a royal attribute becomes a king.  A combinator attribute placed onto an empty square becomes an immobile combinator piece; it cannot move or capture, but it can only be captured by friendly pieces.  (Thus useful for blocking enemy pieces; a combinator-piece combination, however, can of course be attacked and captured by enemy pieces.)
    B) An attribute placed onto a friendly piece is "added" to the friendly piece.  For example, a bishop attribute placed onto a friendly rook becomes a queen.  Likewise, a knight attribute placed onto a friendly bishop becomes a cardinal.  A knight attribute placed onto a friendly knight becomes a "knight squared", which is a knight-rider of range two; a knight attribute placed onto a friendly "knight squared" becomes a "knight cubed" which is a knight-rider of range three.  A bishop or rook attribute placed onto a friendly bishop or rook attribute respectively, become a "bishop squared" or "rook squared", which move just the same as their singlet pieces, but are potentially more useful in certain situations.  No combinator attribute can be placed onto a piece with a combinator attribute.
    C) An attribute placed onto an enemy piece with the identical attribute subtracts from the enemy piece.  Thus a knight attribute placed onto an enemy knight results in the annihilation of the enemy knight; both knight attributes are removed from the game (i.e., neither is returned to either player's attribute reserve).  A knight attribute placed onto an enemy cardinal results in the knight-attributes canceling, leaving an enemy bishop on the square.  Again, both knight attributes are removed from the game.  Attributes cannot be placed onto enemy pieces that do not possess that attribute, so for example a knight attribute cannot be placed onto an enemy bishop, since it cannot be sensibly subtracted.  No combinator attribute can be placed onto a piece with a combinator attribute.  Finally, it is disallowed to place an attribute onto an enemy piece if the same attribute was placed on the same piece by the opponent as his or her previous move.
Note that only a single attribute may be placed on the board per turn, and that one's turn is finished after placing the attribute.

2) Moving a piece:  By definition, a piece may only be moved onto a "valid" square, as described above.  Pieces move only according to their attributes; so for example a knight-opawn can make either a knight's move or an opawn move; a knight-opawn combinator can move as a knight and/or opawn in any order.  All pieces move as they capture, except for opawns and their derivative pieces, which, as mentioned above, can move one or two squares orthogonally but capture one square diagonally in any direction.
Moves onto empty squares are intuitive; however captures are somewhat more complex.
Pieces capture by moving directly onto the square of another piece.  Important: A player may capture ONLY IF he has a royal piece on the board.  Thus, in the initial stage of the game, a player may place pieces without having a royal piece on the board, but he or she may not capture, until he or she has placed his or her royal piece and while it remains on the board.  Pieces may capture A) a friendly piece, or B) an enemy piece
    A) If a piece captures a friendly piece, the two pieces sum.  For example, a knight capturing a friendly bishop becomes a friendly cardinal on the destination square.  One cannot capture a friendly combinator piece with another friendly combinator piece; it is disallowed for pieces to possess more than one combinator attribute, and any move which would cause this to occur is illegal.
    B) If a piece captures an enemy piece:  first, all attributes common to the two pieces are cancelled out, and those cancelled attributes belonging to the capturing piece are returned to the capturing player's attribute reserve; second, what is left of the captured piece, if anything, is removed from the board.  All attributes of the captured piece are removed from the game (i.e., they are not returned to either player's attribute reserve).  For example, when a combinator-knight captures an enemy combinator-cardinal, the following occurs: first the knight attribute and the combinator attribute cancel out; the attacking combinator-knight has been wiped out and its knight and combinator attributes sent back to the attacker's attribute reserve; and the combinator-cardinal has been reduced to a bishop which is then removed (with the bishop attribute not returning to either player's attribute reserve), leaving the attacked square empty and both pieces off the board..
There are some points to be clarified with respect to "combinator" pieces and multiple-knight pieces.  Multiple-knight pieces without combinator abilities move as limited-range knight-riders, which means that they cannot capture and then continue to move.  Combinator pieces, however, can capture on potentially intermediate squares, and this has effects on their ability to make further moves within the turn.  If a capture is made in the middle of a combinator-type move, the piece's attributes are updated according to the above-described capture procedure, and any further movement is made according to the pieces remaining unutilized attributes.  For example. if a combinator-cardinal makes a bishop move and captures an enemy knight, the enemy knight is removed, a knight attribute is returned to the capturing player's attribute reserve, the capturing combinator-cardinal becomes a combinator-bishop, and it can make no further moves (since it has already made a bishop move).  However, if a combinator-cardinal makes a knight move and captures an enemy knight, although it has again become a combinator-bishop, it can make a further bishop move in the same turn, if desired (because the piece had not yet made a bishop move).  Analogously, if a combinator-cardinal makes a knight move and captures a friendly knight, it becomes a combinator-cardinal-knight, and can further move as a combinator-cardinal to finish the turn, if desired.  If a combinator-cardinal makes a bishop move and captures a friendly knight, it again becomes a combinator-cardinal-knight but this time it can further move as a combinator-knight-squared to finish the turn, if desired.  A final note about combinator-kings: kings are allowed to move through or into check or even capture into check during the course of a multi-part move, but they are not permitted to end their move in check.

3) Splitting up a piece: A piece can split into constituent attributes in any desired combination.  Any subset of attributes can move - as a newly created piece - from the originating square to a valid destination square; or the component attributes can be returned to the player's reserve; in both cases leaving behind the residual attributes on the original square as the remaining piece.  A selected piece can split up into multiple different pieces in a single turn, so long as each newly formed "sub-piece" moves (necessarily) to a valid square or is, (as its constituent attributes), returned to the splitting player's reserve.
For example, a player with the ludicrously powerful "queen-squared-cardinal-squared-opawn-squared-combinator" could, in a single move, conceivably split it up into 1) a queen-combinator on the original square, 2) a queen moved from the original square onto a second square, 3) a cardinal-opawn moved to a third square, 4) a cardinal moved to yet a fourth square, and 5) an opawn attribute returned to the player's reserve.  Clearly, building up very strong pieces is desirable, because not only are they able to move almost anywhere on the board... they are also able to move to several "almost anywheres" at the same time!
A further detail worth clarifying is that royal pieces may spit up, so for example, a king in check may avoid check by splitting up such that the royal attribute is returned to the checked player's attribute reserve.  Note, however, that while that player's royal attribute is not on the board as a royal piece, that player cannot capture; and further, that if a player has no pieces left on the board at the end of his or her turn, he or she loses the game.  Thus, removing the royal piece from the board is not a way to indefinitely postpone losing the game.


Possible pieces are too numerous to list, but a basic run-through may help solidify the understanding of combination pieces and higher-degree "purebreds" vs. combinator pieces.

Several basic combinations are already familiar: the rook-bishop is better known as the queen; the rook-knight is known as the marshall, and the knight-bishop is known as the cardinal, the queen-knight is known as the amazon.  However, the opawn is not a familiar piece, and in combination with other attributes it creates a new series of fairly strong, novel pieces: the opawn-knight, opawn-bishop, opawn-rook, opawn-cardinal and opawn-marshall, etc.

What if one combines several attributes of the same type in a single piece?  Then one obtains the opawn-squared, knight-squared, bishop-squared, rook squared etc.  The opawn-squared is still limited to capturing only on adjacent diagonal squares (it cannot capture twice, because, like a knight-rider, it is not a combinator piece.)  Otherwise, it may move up to four spaces in any orthogonal direction without capture.  The opawn-cubed can capture one square diagonally or move up to six spaces in any orthogonal direction without capture; the fourth-degree-opawn up to eight non-capturing spaces in a single orthogonal direction, and so on.  The knight-squared is a knight-rider with a range of two knight moves, the knight-cubed is a knight-rider with a range of three knight moves, and so on.  The bishop-squared and rook-squared do not have additional movement capability over their singlet counterparts; their potential advantage is retaining their movement ability should the opponent place a bishop or rook attribute onto them.  They are also possible intermediates on the way to a bishop-squared or rook-squared combinator.  However, I think they are not particularly strong pieces for the number of attributes they use up, and in some sense the principle of hybrid-vigor applies when combining attributes.  An amazon is certainly stronger than a rook-cubed, for example.

Kings can be combined with any number of other attributes to create royal pieces with enhanced movement abilities.  The ability to create a very mobile king is necessary, given the very powerful attacking pieces with which it may have to contend..  However, it is not wise to sink too many attributes into the royal piece, since regardless of any movement capabilities it may acquire, it may only capture as a king.  This implies that a non-combinator royal piece cannot deliver check to an enemy king, and it is not very useful as an offensive piece.

The combinator attribute is the most powerful attribute in the game.  By itself, it creates an immobile piece that cannot be captured by the enemy (useful for blocking attacks, or putting right next to the enemy king <grin>), but it can be captured by friendly pieces (useful for tactical combinations!).  In combination with just a few other attributes, it can create pieces of truly obscene power.  For example, a combinator-opawn-squared is already a very strong piece.  In addition to being able to move up to four squares orthogonally without capture, it is capable of capturing any piece adjacent to it and also attacks a good number of squares two and three king-moves away.  When capturing pieces diagonally adjacent to it, it can first capture and then move orthogonally, or first move orthogonally and then capture, thus choosing its destination-square.  Lastly, it can extend its move by capturing a friendly piece, and using the additional attribute(s).  Clearly, the combinator-opawn-squared is much more powerful than an opawn-squared; even approaching the strength of a normal queen.  A combinator-amazon is a terrifying piece capable of reaching almost every square on the chessboard; simply by being on the board it probably places the enemy king in check.    

A final technical note which gives an idea of how complicated things become when combinators get involved:  A combinator-king with one or two additional attributes can be very powerful; for example, it can deliver check to the opponent's king - without itself being in check, and despite being restricted to capturing via kings-move throughout the course of the combinator move.  How?  Well, so long as the king can execute a combinator move which 1) captures the opponent king (via a king move) and 2) still ends the turn without itself being in check, then it is checking the opponent king.  Note: combinator kings may move through check in the course of their move, but may NEVER end the turn in check, and they must ALWAYS move out of check if they are placed into it by the other player.  In fact, avoiding check takes precedence over winning the game; one cannot make any move that would win the game but would leave one's king in check.  This rule is to make the game more forcing, avoid losses by oversight of a possible king-capture, and avoid some sticky questions about the legality of various combinator-king moves, checks, and captures (e.g.. does a king capturing another king destroy both king attributes, thus causing both players to lose?  answer: you never capture the enemy king in practice; the enemy king must move out of check somehow, and if it cannot, the opponent is mated and you have won; however you cannot make any move that would place you into check, nor can you check using a capturing threat which you cannot legally execute, such as with an absolutely pinned piece or king that cannot capture the enemy king without ending the turn in check)  The grammar is convoluted, but the rule *should* make sense (if you read it a few dozen times.)


A player loses when 1) He has no pieces on the board at the end of his turn.  2) He has no legal placements or moves.  3) He has a royal piece on the board, and it is checkmated*.  4) He resigns.  5) He runs out of time.
And of course, a player wins when her opponent loses.  A draw occurs only through threefold repetition, by insufficient material to win, or by agreement between the players.

*This is a special case of condition two, because before all else, one must move out of check.