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, written 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 1: the immobilizer does not capture.
66 Note 2: for passive captures, a 'X' is added at the end of the move notation,
67 to indicate that something was taken (replaying the game is necessary to know where).
72 If at the end of its movement a pawn is horizontally or vertically adjacent to an
73 enemy piece, which itself is next to a friendly piece (in the same direction),
74 the "pinced" unit is removed from the board.
76 figure.diagram-container
78 | fen:7k/5ppp/2N5/2n5/3rB3/8/PPP5/K7:
79 figcaption 1.Pc2c4 captures both coordinator and long leaper.
81 h4 Coordinators (rooks)
84 Imagine that rook and king of the same color are two corners of a rectangle
85 (this works if these two pieces are unaligned).
86 If at the end of a rook move an enemy piece stands in any of the two remaining
87 corners, it is captured.
89 figure.diagram-container
91 | fen:8/2b4K/2q5/3p1N1p/8/8/2R5/k7:
92 figcaption 1.Rc5 captures on c7 and h5.
94 h4 Long leapers (knights)
97 A knight captures exactly as a queen in international draughts game: by jumping
98 over its enemies, as many times as it can/want but always in the same direction.
99 In this respect it is less powerful than a draughts' queen:
100 on the following diagram c8 or f6 cannot be captured.
101 However, the knight does not have to maximize the number of captured units
102 (as is the case in draughts).
104 figure.diagram-container
106 | fen:2n4k/3r4/5b2/3p4/1m6/3b4/3N4/K7 d4,d6,d8,a5:
107 figcaption All marked squares captures are playable from d2.
109 h4 Withdrawer (queen)
112 The queen captures by moving away from an adjacent enemy piece, in the opposite
113 direction (without jumping, the path must be free).
115 figure.diagram-container
117 | fen:7k/8/8/3Qr3/8/8/8/K7 a5,b5,c5:
118 figcaption 1.Qa5, 1.Qb5 or 1.Qc5 captures the black rook.
120 h4 Chameleon (bishop)
122 p The chameleon captures pieces in the way they would capture. So, it
124 li pinces pawns (if moving like a pawn),
125 li withdraws from withdrawers,
126 li leaps over long leapers,
127 li coordinates coordinators.
128 p ...and these captures can be combined.
131 Remark: the move indicated on the diagram doesn't capture the black pincer
132 on e5, since it is a diagonal move (not like a pawn).
134 figure.diagram-container
136 | fen:7k/8/8/r3pP2/2n5/8/B7/K7 a5,c4:
137 figcaption 1.Bd5 captures the two marked pieces.
140 Besides, chameleon immobilizes immobilizers (but cannot capture them since they
144 A chameleon captures the king in the same way the king captures, which means that
145 a chameleon adjacent to a king gives check.
150 Checkmate or stalemate as in standard chess. Note however that checks are more
151 difficult to see, because of the exotic capturing rules. For example, on the
152 following diagram the white king cannot move to e5 because then
153 the black pawn could capture by moving next to it.
155 figure.diagram-container
157 | fen:7k/8/8/p4r/4K3/8/8/8 e5:
158 figcaption 1.Ke5 is impossible
163 | A good starting point is the
164 a(href="https://en.wikipedia.org/wiki/Baroque_chess") Wikipedia page
165 | , which also gives pointers to other interesting pages (including
166 | chessvariants.com, as usual).