- Amazon (back)
A piece that moves like an orthodox Queen and Knight
- Andernach (back)
A piece change its color (takes the opponent's color) when making a capture. The rule does not apply to Kings.
- Anti Andernach (back)
A piece change its color (takes the opponent's color) when not making a capture. The rule does not apply to Kings.
- Atomic Chess (back)
Any capture also annihilates the capturing unit (Kings, Officers, and Pawns)
plus any piece (Kings and officers, but NOT pawns) in a one square radius.
There is no chain reaction.
Promoted Pawns are treated as pieces (not like pawns).
A move which annihilates your own King is illegal.
In Checkfree Atomic there is no check nor checkmate and the game is won when a King is annihilated, though stalemate is possible.
- Berolina Pawn (back)
A Berolina Pawn has the opposite movement of the orthodox one. It moves (without capturing) diagonally
and captures in the square in front of it.
A BP in c3 may move to b4 or d4 (if they are empty) and captures an opponent piece in c4.
- Camel (back)
The Camel is a leaper on a 1-3 rectangle.
- Chameleon chess (back)
A chameleon piece changes its type after making a move (capturing or not) following the cycle N → B → R → Q → N etc.
In Chameleon Chess all pieces are chameleons.
- Checkless chess (back)
A fairy condition where check is illegal unless it is checkmate.
- Chinese Pieces (back)
Chinese pieces move like their western correspondent, but, in order to capture, they have to hop over a piece (own or not),
on their line of action (like a lion.
According to their movement they are:
- Leo (back)
- Pao (back)
- Vao (back)
- Mao (back)
It is considered a chinese piece, but its movement is that of a Knight didived into two steps:
first orthogonally and then diagonally. The intermediate square must be empty, therefore a Mao can be interfered with.
- Moa (back)
Like Mao, but the steps are reversed: first diagonally then orthogonally.
- Circe (back)
When a piece is captured it is immediately reborn on its birth square if it is empty, otherwise the capture is definitive.
A birth square is
Reborn Kings and Rooks may castle.
Circe condition does not apply to Kings unless otherwise specified (i.e. R.I. = Rex Inclusiv)
- Queen: its original square (d1 or d8)
- Rooks, Bishops and Knights the original square of the same color of the square where the piece has been captured. A white Rook captured on c3
is reborn on a1, if it were captured on b3 it would be reborn on h1.
- Pawns: the rebirth square is the one on the same column where the capture has been made. A white Pawn captured on c3 is
reborn on c2.
- Fairy pieces: the rebirth square is the promotion square on the same column.
A white Grasshopper captured on c3 is reborn on c8.
- Anticirce (back)
In Anticirce it is the capturing piece that is reborn according to Circe rules.
Captures are definitive as in orthodox chess.
Capturing is possible only if the rebirth square is empty; capturing from the rebirth square is legal.
Whether capturing on the rebirth square is legal or not has been matter of controversy and has given birth to two sub-variations:
the Calvet type where this capture is legal, and the Cheylan type where it is not.
- Circe Assassin (back)
After a capture the captured piece is reborn even if the rebirth square is occupied. A piece on the occupied square disappears from the board.
If there's a King on that square, that King is in check.
- Couscous Circe (back)
The captured piece is reborn on the capturing piece rebirth square.
- Exchange Circe (Platzwechsel Circe PWC) (back)
The rebirth square of a captured unit is the starting square of the capturing unit: the two pieces therefore swap their place.
- Mars Circe (back)
To make a capture, a unit is first reborn on its Circe rebirth square, which must be empty, and then makes the capture from that square. The captured piece disappears.
- Mirror Circe (back)
In mirror Circe captured pieces are reborn on the birth square of the opponent's similar piece. Thus a white Bishop captured on
c3 is reborn on f8.
- Godfather (Parrain) Circe (back)
In the move immediately after a capture, the captured piece makes, if possible, a move (from the square where it was captured) parallel to
the moving piece. If that new move is impossible then the piece is captured.
E. G. after 1. e4 d5 2. e4:d5 if black plays Sg8-f6, the pawn plays from d5 to c3, while after 2 ... Bc8-h3
it disappears definitively from the chessboard.
- ContreParrain Circe (back)
Like Circe Parrain, but rebirths are shifted 180 degrees.
Thus, captured units are immediately reborn the same distance,
but opposite direction, from the capture square, as the move following
their capture (e.g., if wKxbPc3 were followed by ...Nd2-e4 black's pawn
is immediately reborn, and promoted, on b1).
If the rebirth square is off the board, or already occupied,
the captured unit is annihilated.
To determine rebirths after castling moves, apply the sum of
King and Rook movements, then shift direction 180-degrees
(thus, as in Circe Parrain, short castling only results in a rebirth if preceded by an en passant capture, whereas long-castling results in a rebirth one square
to the West of the capture square -- as opposed to one square East, in Circe Parrain).
- Circe Turncoats (back)
When a piece is captured it takes the opponent color and is reborn on that piece's rebirth square.
A WQ captured on c3 is reobrn as a Black Queen in d8.
- UltraCirce (Pongracz Circe) (back)
Like Circe, but with the following extra rules:
a) A captured piece is only removed from the board, if its rebirth square is occupied by a piece of his own colour.
b) "Continued rebirth": If a piece is captured on its own rebirth square, or if the rebirth square
is occupied by an enemy piece, when the piece is
captured, [b]neverthelessthen the captured piece is reborn. The enemy piece occupying the rebirth square (in the first case, this is the capturing piece)
is captured as part of the capturing move, and the thus captured enemy piece is reborn - the Circe and Ultracirce rules apply for this piece as well.
Therefore, capture series are possible. Such a series end, if (1) a piece is reborn on an empty square, or if (2) its rebirth square is occupied by
a piece of its own colour (then the piece is removed from the board).
- Cologne Contact Chess (back)
A move is possible only if the piece moved arrives on a square next to another unit.
- Consequent (back)
The legality of the move is considered regardless of the past moves. If white has a K in e1 and a R in h1 and nothing prevents castling then he can castle, even
if one of the piece has just arrived in its position.
- Einstein Chess (back)
When a piece captures it is promoted: a P becomes a S, S => B, B => R, R => Q, Q => Q
When a piece does not capture it is demoted: a Q becomes a R, R => B, B => S, S => P, P => P
- Anti Einstein Chess (back)
Like Einstein chess when a piece doesn't capture, but the piece doesn't change when it captures.
- Dragon (back)
Moves like a Knight and a Pawn. A Dragon cannot promote.
- Empress (back)
The Empress is a fairy piece that moves like an orthodox Knight and Rook.
- EquiHopper (back)
Piece moving like a Leaper until it reaches an occupied square. Then, from that square, without changing direction,
it makes an identical leaper leap. A Equihopper moves in the same way to capture or not to capture, the taken unit being on the arrival squar
An Equihopper in a1 with a piece in c3 (any color) can move to 'd5' hopping over c3.
An Equihopper in a1 with a piece in b3 (any color) can move to 'c5' hopping over b3.
- Extinction Chess (back)
Check and checkmate do not apply; the first player that does not have pieces (including pawns) of all
types loses the game. Pawns may promote to any other type of piece, including Kings.
When a Pawn promotes to some type of piece, this piece is also counted among the pieces
of the type.
If a player promotes his last Pawn, he loses (as his Pawns are now extinct), unless he wins by
extinction on that very move. Since there is no check, castling under or through check is allowed.
- Gnu (back)
The Gnu is a fairy piece that sums up the movement of a Knight and of a Camel.
- Grasshopper (back)
The Grasshopper is a fairy piece that moves (on Queen lines) by hopping over a piece (of any color) and arriving on the square immediately behind if it
is free or occupied by an enemy piece (which is captured).
- Grasshopper-N (back)
Like Grasshopper but the arrival square is not the one immediately after but n steps further.
- Hamster (back)
Moves like a Grasshopper, but goes back over the hurdle. The arrival square is therefore just before the hurdle.
- Haan Chess (back)
After each move, the starting square of the move becomes a hole, i.e. a
square which can never again be either occupied or crossed.
- Helpselfmates (Hs#) (back)
Type of problems where both colors play to arrive in a position in which White can force a Selfmate in one. By convention White begins (unlike other help problems).
- Invisible pieces (back)
An Invisible piece is a piece which stands somewhere on the board, but whose identity and whereabouts is not known.
The real identity of Invisible is any ordinary piece (including K if there is no K on the board).
It is assumed that the initial position and the sequence of moves must be legal after the true identity of every Invisible is revealed.
After the true identity and whereabouts of Invisible is revealed, it becomes visible and turns into an ordinary piece.
We denote an Invisible move simply by 1.I-- (we don't know which Invisible moved to what square) and a capture by Invisible by 1.Ixd2
for example (in this case we know at least Invisible moved to what square). A capture of Invisible can be done only when the capture
can be proved if the move is playable. "Check" is ascertained only when the move is check in an ordinary
sense in every possible configuration of Invisibles. Similarly, "checkmate" is ascertained only when the move is checkmate in an
ordinary sense in every possible configuration of Invisibles. (Tadashi Wakashima - August 2009)
- Lion (back)
The Lion is a fairy piece that moves hopping over any piece and landing on a square after the hurdle (capturing if there is an enemy piece).
It's not possible to hop over more than one piece. The Lion moves along Queen lines, otherwise the piece is named Rook-Lion or Bishop-Lion and likewise.
- Locust (back)
The Locust moves like a Grasshopper but hopping only over an enemy piece which is captured. The arrival square
must be empty. Locust can move only capturing.
Locust-like pieces move along the lines of rook bishop nightrider etc.
- Losing Game (back)
Capturing is mandatory, when more than one are possible the choice is free. King is a normal piece and can be captured.
A pawn may promote to King. Win is reached by the color that has no more moves either because it has no more pieces or because it is stalemated.
Many variations of the game exist (about castling, draw etc.) including the one in which stalemate is a draw as was played in Italy.
- Madrasi (back)
Like movement pieces (Queen-Queen, Rook-Rook etc.) paralyze each other on their movement lines. A paralyzed piece cannot move nor
capture nor therefore give check.
Madrasi condition does not apply to Kings unless otherwise specified (i.e. R.I. = Rex Inclusiv)
- Masand (back)
When a piece moves, if it attacks directly the opposite King, it also changes the color of the pieces it controls or attacks, except the Kings.
- Maximummer (back)
The color to whom the condition is applied is obliged to make the longest possible move, where the length is measured from the
center of the starting square to the arriving square. Castles' lenght is the sum of the two movements (therefore O-O is 4 and O-O-O is 5).
When the length is the same, the choice is free.
Condition is more frequently applied to black in selfmates, but can also be applied to White or to both colors (double maximummer).
- Monochromatic chess (back)
A move is legal only when both starting and arrival squares are of the same color. K-castle is possible, Q-Castle is not.
Knights don't move. En passant capture is always legal.
- Multicaptures chess (back)
A unit (including Kings) can be captured only when it is attacked in two ways.
- Nightrider (back)
A fairy piece that moves like Bishops or Rooks but along the Knight lines. A Nightrider in a1 may move to b3-c5-d7 or c2-e3-g4.
- Nightrider hopper (back)
Like the Grasshopper, but on the lines of the
- Neutral pieces (back)
Neutral pieces may be played by both Black and White. They can capture and be captured by pieces of any color (including neutral ones). A King cannot be in check of a neutral piece.
When there's a neutral King the first color that mates him wins.
- Orphan (back)
The Orphan is a dummy piece that moves (and captures) only when it is threatened by an opponent piece in which case it takes the power
of the attacking piece. The propriety is transmitted to other orphans: with wOc3, bBa5 and bO d2, the Od2 can move like a Bishop because it is
attacked by the Oc3 which is in turn attacked by the Ba5.
- Patrol Chess (back)
A piece can capture only when it is protected (by a friend unit).
- Progressive Chess (back)
White starts the game by playing one move, Black answers with two and so on, always increasing by one the length of the series.
Check may only be given with the last move of a series and must be defended with the first one. In direct problems White starts by
playing one move, a direct two mover is indicated by PR 1.2.3#
- Pressburger King (back)
Like Transmuted King but the King takes definitively the power of the checking pieces (powers are added in case of further checks).
- Psycho Pieces (back)
A Psycho piece moves like Rook Bishop or Knight, but it (temporarily) loses the latest power it used.
A Psycho moving from a1 to a2 (i.e. like a Rook) may move from a2 only like a Bishop or a Knight.
The symbol appearing on the diagram is the type of piece that made the last move.
- Retractors (back)
Problems in which White or Black retracts n move to reach a position for a normal forward problem.
The easiest case is when White retracts its last move and mates in one, but there are much more
- Proca (back)
In Proca retractor, white retracts n moves to reach a position for a normal problem (usually a #1). White must
retract a legal move, Black defends by retiring any move he wishes.
- Hoeg (back)
In Hoeg retractor, white retracts n moves to reach a position for a normal problem (usually a #1). White must
retract a legal move, but Black may decide if that last move was a capture and, in the case, which piece was captured.
- Rex multiplex (back)
A color is mated only when all its Kings are mated. A check (which is not mate) is legal only if the defendent can move without having one of its
Kings in check. Pawns may promote to King.
- SAT (back)
A side is checked only when its king can move according to other (orthodox or other given fairy) rules.
- Sentinel Chess (back)
All pieces (not pawns) when moving leave a sentinel on its starting square, i.e. a pawn of its own color. The rule is
limited by the number of own pawns that must not exceed eight and by the fact that a pawn may not appear on the first or eighth rank.
The limitation means that the move is still legal and is done without leaving any pawn behind.
- Series problems (back)
Type of problems in which one (or both) color may make a series of consecutive moves (without of course capturing the other King). Normally check
may be given with the last move and must be defended with the first move of the series. The most common use is in help(mate or stalemate) in series in
which Black plays n moves so that White can (stale)mate in one but many other possibilites exist.
- Shortest Proof Game (back)
A type of problem where the solver must find a game that will result in the diagram position after a legal game of the given number of moves.
If a shorter solution exists the problem is cooked, unless otherwise specified (the indication PG should be enough, but it's normally specified
as PG in exact number of moves. A move is a full move by white and black, so that when a non-integer number is indicated it means tha white moved
last, e.g. after 1. e2-e4 the number of moves is 0.5, after 1. e2-e4 e7-e5 it's 1.0 and so on.
- Squirrel (back)
The Squirrel is a [2,0] + [2,1] + [2,2] leaper. The Squirrel moves on the perimeter of a 5-squares square whose center
is occupied by the Squirrel itself.
From c3 a Squirrel can move to a1, a2, a3, a4, a5, b5, c5, d5, d5, e4, e3, e2, e1, d1, c1 , b1, a1.
- Sting Chess (back)
Sting Chess is a normal game of chess where the Kings are Scorpions (i.e. Kings with the additional power of a Grasshopper)
- Take&make (back)
When a piece captures, it must make immediately a new move, according to the captured piece's movement. Legality is checked only
at the end of both moves. Pawns move differently depending on the color (white upwards, black downwards).
Promotion is done when a pawn ends its move on the eigth rank.
If it's not possible to make the
second part of the move, then the move is illegal. Capture of the king is orthodox (i.e. there's no need to make the second part of the move).
- Tibet Chess (back)
A black piece (not K) when capturing a different type of piece changes its color.
A pawn capturing and promoting to a piece different from the captured one also
changes its color.
- Transmuted King (back)
A King in check moves only like the piece(s) giving check.
- SuperTransmuted King (back)
A King in check moves only like the piece(s) giving check; from that moment he will keep the new power, but will lose the
- UltraSchachZwang (back)
Black must always give check.
- Volage (back)
A Volage piece changes its color the first time it makes a move that changes the color of the squares. Afterwards
it becomes orthodox. The rule does not apply to Kings.
- HyperVolage (back)
A hypervolage piece changes its color every time it makes a move that changes
the color of the squares. The rule does not apply to Kings.
- Wazir (back)
The Wazir is a fairy piece that moves one square orthogonally (leaper [0, 1]). A Wazir on c3 can move to c4, c2, b3, d3.
- Zebra (back)
The Zebra is a fairy piece that leaps like a Knigth, but moving by 2x3 squares (leaper [2, 3]). A Zebra in c3 can move to f1, f5, e6, a6.