Chess Variants/Ultima

Introduction
Ultima, also known as Baroque chess, is an eclectic variant where the pieces differ in the powers of capture, rather than their powers of movement.

History
Ultima was created by veteran game designer Robert Abbott in 1962. The rules were initially published in the August 1962 issue of the Recreational Mathematics magazine, and the variant was given the name "Baroque chess" via a contest, but the variant would receive its current name the following year.

In 1968 Abbott made a slight alteration to the rules, adding a new rule that stated a piece on the Nth rank could move no further than N squares. The chess variant community has mostly rejected this change and continues to play Ultima by the 1962 rules, of which the page will detail the most common variation.

Rules
Ultima is played using the same board and pieces as standard chess. However the pieces have different names and movement powers, and most notably all of them capture in a unique way. The pieces are as follows: Before play begins, the players are allowed to decide which one of their rooks will be the immobiliser (that rook is turned upside down), and if they want to switch the positions of their king and withdrawer. After these two factors have been settled, White moves first like in standard chess.

Due to the unique nature of captures in this variant, the end goal is no longer checkmate - the king must actually be captured before the game ends.

The king
The king moves just like his orthodox chess counterpart - one square at a time in any direction. He captures by the traditional method of displacement used in orthodox chess - the king moves into the square of the enemy piece and takes its place.

The pincer pawn
Represented by the pawn, the pincer pawn moves like an orthodox rook. It captures using a technique known as custodial capture – if a pincer pawn makes a move that sandwiches an enemy piece between the pincer pawn and a friendly piece, the enemy piece is captured. There may be no gaps in the formation, and custodial captures can only happen vertically or horizontally – not diagonally. If an enemy piece moves into the formation on its own accord, the capture does not happen.

The long leaper
Represented by the knight, the long leaper moves like an orthodox queen. It captures by means of leaping – as it moves, if the long leaper encounters an enemy piece with an empty square beyond it in the its direction of movement, it may jump over that piece and land on the square beyond, capturing the piece. Multiple pieces may be captured in this manner if there are gaps available to land on.

The withdrawer
Represented by the queen, the withdrawer moves like an orthodox queen. It captures by withdrawing – if it starts the turn adjacent to an enemy piece and moves directly away from it, that piece is captured.

The coordinator
Represented by the rook, the coordinator moves like an orthodox queen. It captures by coordination – after the coordinator has moved an invisible orthogonal cross of squares is drawn from the coordinator’s position, and another such cross is drawn from the position of the friendly king. Any enemy pieces on the two squares where these crosses intersect are captured.

The immobiliser
Represented by an upside-down rook, the immobiliser moves like an orthodox queen. It cannot capture enemy pieces, but instead it can immobilise them. Any enemy piece that is directly adjacent to the immobiliser is immobilised – it will be completely unable to move until the immobiliser moves away.

If a player wishes to, then instead of moving a piece they may have an immobilised piece commit suicide, removing it from the board.

The chameleon
Represented by the bishop, the chameleon (also known as the imitator) moves like an orthodox queen. It captures enemy pieces by using their own powers of capture against them – so it would capture enemy long leapers by jumping over them, for instance. Note that chameleons cannot capture enemy chameleons.

Also, if a chameleon moves adjacent to an enemy immobiliser, the two pieces will freeze each other, leaving both unable to move.

Pieces in detail
These pieces may be confusing, so what follows is a series of diagrams to help you understand.

King
The white king, currently in check from the black withdrawer on d3 moves from c4 to d5, delivering chackmate. Under normal circumstances this would be an illegal move, however the black king is currently being immobilised by the white immobiliser on f4, and so it is not attacking d5.

The king would not be allowed to move to d4 since there it would still be in check from the withdrawer. If the king captured the withdrawer by moving to d3, the result would be stalemate since Black would no longer have any available moves.

Pincer Pawn
The white pincer pawn on g4 moves to d4, capturing the black pincer pawn on d5 and the black immobiliser. The black withdrawer is safe from capture since custodial captures only happen horizontally or vertically, not diagonally. The black chameleon is safe since d2 is not occupied by a white piece. Finally the black long leaper on g3 is safe because it moved into the formation on its own accord, rather than a pawn moving to complete the custodial capture.

Withdrawer
The white withdrawer on g6 moves to d3, capturing the black pincer pawn on h7. The pincer pawn on g7 and the chameleon are safe because the withdrawer did not move directly away from them. Note how the withdrawer also delivers check to the king by threatening to move away on the d-file.

Long Leaper
The white long leaper on d2 jumps to d4, then d6, then d8, capturing three black pieces in the process - namely the pincer pawn on d3, the long leaper on d5 and the coordinator on d7. It could have instead captured the withdrawer with a jump to g5. On the other hand the pincer pawns on b2, f2 and g2 and the chameleon are safe since the long leaper cannot land immediately beyong them.

Coordinator
The white coordinator on d4 moves to f6, and by coordinating with its king on c2 it captures the black long leaper on c6 and the black immobiliser on f2. It could have instaed captured the leaper and the pincer pawn on d2 by playing to d6.

Immobiliser
The white immobiliser on f3 moves to d5, immobilising five black pieces. The previously immobilised black long leaper on g4 is now free to move again. In the process the immobiliser is itself immobilised by the black chameleon on c6. Any of the immobilised black pieces may commit suicide on Black's next turn if they so want to.

Chameleon
The white chameleon on g6 jumps to e6 and then c6, capturing all of Black's non-king pieces in one turn and delivering check. It captures:


 * The withdrawer by moving away from it.
 * The long leapers by jumping over them.
 * The pincer pawns by sandwiching them against friendly pieces.
 * The coordinator by rank/file coordination with the friendly king.

It also delivers check by threatening to step into the king's square.

Sub-variants

 * Maxima, created in 2003, is a larger version of Ultima on an 8x9 board with two extra pieces.
 * Optima is similar to Maxima, with additional pieces and rules.
 * Renaissance uses new pieces and allows captured pieces to be revived by a special technique.
 * Rococco is played on a 10x10 board with an extra piece.