Fix some typos in rules
[vchess.git] / views / rules / Ultima / en.pug
CommitLineData
32cfcea4 1p.boxed
2f3c8451 2 | Most pieces look the same but behave very differently.
32cfcea4 3 | They generally move like an orthodox queen,
2eef6db6 4 | but capturing rules are complex.
32cfcea4
BA
5
6h3 Specifications
7
8ul
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.
2f3c8451 14 li End of game: standard; see below.
32cfcea4 15
15c1295a
BA
16h4 Pieces names
17
18p Pieces names refer to the way they capture, which is described later.
19ul
20 li Pawn : pawn or pincer
21 li Rook : coordinator
22 li Knight : long leaper
23 li Bishop : chameleon
24 li Queen : withdrawer
25 li King : king (same behavior as in standard chess)
26p.
b41d5704 27 Besides, a new piece is introduced: the immobilizer, written by the letter 'm'
15c1295a
BA
28 in FEN diagrams and PGN games. It is represented by an upside-down rook:
29
30figure.diagram-container
31 .diagram
32 | fen:8/8/4m3/8/8/8/3M4/8:
33 figcaption Immobilizers on d2 and e6.
34
32cfcea4
BA
35h3 Non-capturing moves
36
b41d5704
BA
37p.
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.
15c1295a 41
2316f8b8
BA
42p.
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).
15c1295a
BA
46p
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.
2316f8b8
BA
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.
32cfcea4
BA
53
54h3 Capturing moves
55
b41d5704
BA
56p.
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.
15c1295a 62
da06a6eb
BA
63p Note 1: the immobilizer does not capture.
64
65p.
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).
15c1295a
BA
68
69h4 Pawns/Pincers
70
71p.
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.
75
76figure.diagram-container
77 .diagram
78 | fen:7k/5ppp/2N5/2n5/3rB3/8/PPP5/K7:
79 figcaption 1.Pc2c4 captures both coordinator and long leaper.
80
81h4 Coordinators (rooks)
82
83p.
b41d5704
BA
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).
15c1295a
BA
86 If at the end of a rook move an enemy piece stands in any of the two remaining
87 corners, it is captured.
88
89figure.diagram-container
90 .diagram
91 | fen:8/2b4K/2q5/3p1N1p/8/8/2R5/k7:
92 figcaption 1.Rc5 captures on c7 and h5.
93
94h4 Long leapers (knights)
95
96p.
3ad85eac
BA
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.
15c1295a
BA
99 In this respect it is less powerful than a draughts' queen:
100 on the following diagram c8 or f6 cannot be captured.
3ad85eac
BA
101 However, the knight does not have to maximize the number of captured units
102 (as is the case in draughts).
15c1295a
BA
103
104figure.diagram-container
105 .diagram
643479f8 106 | fen:2n4k/3r4/5b2/3p4/1m6/3b4/3N4/K7 d4,d6,d8,a5:
3ad85eac 107 figcaption All marked squares captures are playable from d2.
15c1295a
BA
108
109h4 Withdrawer (queen)
110
111p.
112 The queen captures by moving away from an adjacent enemy piece, in the opposite
b41d5704 113 direction (without jumping, the path must be free).
15c1295a
BA
114
115figure.diagram-container
116 .diagram
643479f8 117 | fen:7k/8/8/3Qr3/8/8/8/K7 a5,b5,c5:
15c1295a
BA
118 figcaption 1.Qa5, 1.Qb5 or 1.Qc5 captures the black rook.
119
120h4 Chameleon (bishop)
121
122p The chameleon captures pieces in the way they would capture. So, it
123ul
05084186 124 li pinces pawns (if moving like a pawn),
15c1295a
BA
125 li withdraws from withdrawers,
126 li leaps over long leapers,
127 li coordinates coordinators.
128p ...and these captures can be combined.
129
05084186
BA
130p.
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).
133
15c1295a
BA
134figure.diagram-container
135 .diagram
05084186
BA
136 | fen:7k/8/8/r3pP2/2n5/8/B7/K7 a5,c4:
137 figcaption 1.Bd5 captures the two marked pieces.
15c1295a
BA
138
139p.
140 Besides, chameleon immobilizes immobilizers (but cannot capture them since they
141 do not capture).
142
143p.
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.
32cfcea4
BA
146
147h3 End of the game
148
15c1295a
BA
149p.
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
b41d5704 152 following diagram the white king cannot move to e5 because then
15c1295a
BA
153 the black pawn could capture by moving next to it.
154
155figure.diagram-container
156 .diagram
643479f8 157 | fen:7k/8/8/p4r/4K3/8/8/8 e5:
15c1295a 158 figcaption 1.Ke5 is impossible
32cfcea4
BA
159
160h3 Credits
161
162p.
b41d5704
BA
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).