2 | Most pieces look the same but behave very differently.
3 | They generally move like an orthodox queen,
4 | but capturing rules are complex.
9 li Chessboard: standard.
10 li Material: "standard".
11 li Non-capturing moves: often like queen.
12 li Special moves: none.
13 li Captures: very special.
14 li End of game: standard; see below.
18 p Pieces names refer to the way they capture, which is described later.
20 li Pawn : pawn or pincer
22 li Knight : long leaper
25 li King : king (same behavior as in standard chess)
27 Besides, a new piece is introduced: the immobilizer, represented by the letter 'm'
28 in FEN diagrams and PGN games. It is represented by an upside-down rook:
30 figure.diagram-container
32 | fen:8/8/4m3/8/8/8/3M4/8:
33 figcaption Immobilizers on d2 and e6.
35 h3 Non-capturing moves
38 | Pawns move as orthodox rooks, and the king moves as usual,
39 | one square in any direction.
40 | All other pieces move like an orthodox queen.
43 When a piece is adjacent to an enemy immobilizer, it cannot move unless
44 the enemy immobilizer is adjacent to a friendly immobilizer or chameleon
45 (cancelling the powers of the opponent's immobilizer).
47 | Note : this corresponds to the "pure rules" described on
48 a(href="http://www.inference.org.uk/mackay/ultima/ultima.html") this page
49 | , which slightly differ from the initial rules.
50 | The aim is to get rid of the weird suicide rule by weakening the immobilizers lock.
51 | In particular, in the original rules two adjacent immobilizer are stuck forever
52 | until one is captured. Note that it's still the case if all chameleons disappeared.
57 | Easy case first: the king captures as usual, by moving onto an adjacent square
58 | occupied by an enemy piece. But this is the only piece following orthodox rules,
59 | and also the only one which captures by moving onto an occupied square.
60 | All other pieces capture passively: they land on a free square and captured
61 | units are determined by some characteristics of the movement.
63 p Note: the immobilizer does not capture.
68 If at the end of its movement a pawn is horizontally or vertically adjacent to an
69 enemy piece, which itself is next to a friendly piece (in the same direction),
70 the "pinced" unit is removed from the board.
72 figure.diagram-container
74 | fen:7k/5ppp/2N5/2n5/3rB3/8/PPP5/K7:
75 figcaption 1.Pc2c4 captures both coordinator and long leaper.
77 h4 Coordinators (rooks)
80 Imagine that rook and king are two corners of a rectangle (this works if these
81 two pieces are unaligned).
82 If at the end of a rook move an enemy piece stands in any of the two remaining
83 corners, it is captured.
85 figure.diagram-container
87 | fen:8/2b4K/2q5/3p1N1p/8/8/2R5/k7:
88 figcaption 1.Rc5 captures on c7 and h5.
90 h4 Long leapers (knights)
93 A knight captures exactly as a queen in international draughts game: by jumping
94 over its enemies, as many times as it can/want but always in the same direction.
95 In this respect it is less powerful than a draughts' queen:
96 on the following diagram c8 or f6 cannot be captured.
97 However, the knight does not have to maximize the number of captured units
98 (as is the case in draughts).
100 figure.diagram-container
102 | fen:2n4k/3r4/5b2/3p4/1m6/3b4/3N4/K7 w d4,d6,d8,a5:
103 figcaption All marked squares captures are playable from d2.
105 h4 Withdrawer (queen)
108 The queen captures by moving away from an adjacent enemy piece, in the opposite
109 direction (only the long leaper can jump).
111 figure.diagram-container
113 | fen:7k/8/8/3Qr3/8/8/8/K7 w a5,b5,c5:
114 figcaption 1.Qa5, 1.Qb5 or 1.Qc5 captures the black rook.
116 h4 Chameleon (bishop)
118 p The chameleon captures pieces in the way they would capture. So, it
121 li withdraws from withdrawers,
122 li leaps over long leapers,
123 li coordinates coordinators.
124 p ...and these captures can be combined.
126 figure.diagram-container
128 | fen:7k/8/8/r3pP2/2n5/8/B7/K7 w a5,c4,e5:
129 figcaption 1.Bd5 captures all marked pieces.
132 Besides, chameleon immobilizes immobilizers (but cannot capture them since they
136 A chameleon captures the king in the same way the king captures, which means that
137 a chameleon adjacent to a king gives check.
142 Checkmate or stalemate as in standard chess. Note however that checks are more
143 difficult to see, because of the exotic capturing rules. For example, on the
144 following diagram the white king cannot move to the marked squares because then
145 the black pawn could capture by moving next to it.
147 figure.diagram-container
149 | fen:7k/8/8/p4r/4K3/8/8/8 w e5:
150 figcaption 1.Ke5 is impossible
155 A good starting point is the
156 #[a(href="https://en.wikipedia.org/wiki/Baroque_chess") Wikipedia page],
157 which also gives pointers to other interesting pages (including chessvariants.com,