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2 <title>Janus Chess</title>
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12 <table cellpadding="20">
14 <td><img src="Janus.png"></td>
17 <h3>Initial setup</h3>
21 b1, b8, i1, i8: Janus<br>
22 a1, a8, j1, j8: Rook<br>
23 d1, d8, g1, g8: Bishop<br>
24 c1, c8, h1, h8: Knight<br>
25 a2-j2, a7-j7: Pawns</p>
30 <h3>Moves at a Glance</h3>
32 <p>Click on a piece below to see its moves</p>
36 <td class="n" id="sq0x9" onmousedown="down_click(2,9)"
37 onmouseup="up_click()"><img src="sym/BlackRook.png"></td>
39 <td class="n" id="sq1x9"></td>
41 <td class="n" id="sq2x9"></td>
43 <td class="n" id="sq3x9"></td>
45 <td class="n" id="sq4x9" onmousedown="down_click(-4,9)"
46 onmouseup="up_click()"><img src="sym/BlackKing.png"></td>
48 <td class="n" id="sq5x9"></td>
50 <td class="n" id="sq6x9"></td>
52 <td class="n" id="sq7x9"></td>
54 <td class="n" id="sq8x9"></td>
56 <td class="n" id="sq9x9" onmousedown="down_click(-9,9)"
57 onmouseup="up_click()"><img src="sym/BlackRook.png"></td>
59 <td class="h"><img src="sym/yellow.png"></td>
61 <td class="w" rowspan="2" valign="top">
62 <p>Sliding capture or non-capture,<br>
63 can be blocked on any square along the ray</p>
68 <td class="n" id="sq0x8"></td>
70 <td class="n" id="sq1x8"></td>
72 <td class="n" id="sq2x8"></td>
74 <td class="n" id="sq3x8"></td>
76 <td class="n" id="sq4x8"></td>
78 <td class="n" id="sq5x8"></td>
80 <td class="n" id="sq6x8"></td>
82 <td class="n" id="sq7x8"></td>
84 <td class="n" id="sq8x8"></td>
86 <td class="n" id="sq9x8"></td>
90 <td class="n" id="sq0x7"></td>
92 <td class="n" id="sq1x7"></td>
94 <td class="n" id="sq2x7"></td>
96 <td class="n" id="sq3x7"></td>
98 <td class="n" id="sq4x7"></td>
100 <td class="n" id="sq5x7"></td>
102 <td class="n" id="sq6x7"></td>
104 <td class="n" id="sq7x7"></td>
106 <td class="n" id="sq8x7"></td>
108 <td class="n" id="sq9x7"></td>
110 <td class="h"><img src="sym/orange.png"></td>
112 <td class="w">Unblockable leap (capture or non-capture)</td>
116 <td class="n" id="sq0x6"></td>
118 <td class="n" id="sq1x6"></td>
120 <td class="n" id="sq2x6"></td>
122 <td class="n" id="sq3x6"></td>
124 <td class="n" id="sq4x6"></td>
126 <td class="n" id="sq5x6" onmousedown="down_click(-5,-6)"
127 onmouseup="up_click()"><img src=
128 "sym/WhiteArchbishop.png"></td>
130 <td class="n" id="sq6x6"></td>
132 <td class="n" id="sq7x6"></td>
134 <td class="n" id="sq8x6"></td>
136 <td class="n" id="sq9x6"></td>
138 <td class="h"><img src="sym/green.png"></td>
140 <td class="w">Non-capture only</td>
144 <td class="n" id="sq0x5"></td>
146 <td class="n" id="sq1x5"></td>
148 <td class="n" id="sq2x5"></td>
150 <td class="n" id="sq3x5"></td>
152 <td class="n" id="sq4x5"></td>
154 <td class="n" id="sq5x5"></td>
156 <td class="n" id="sq6x5"></td>
158 <td class="n" id="sq7x5"></td>
160 <td class="n" id="sq8x5"></td>
162 <td class="n" id="sq9x5"></td>
164 <td class="h"><img src="sym/red.png"></td>
166 <td class="w">Capture only</td>
170 <td class="n" id="sq0x4"></td>
172 <td class="n" id="sq1x4"></td>
174 <td class="n" id="sq2x4"></td>
176 <td class="n" id="sq3x4"></td>
178 <td class="n" id="sq4x4"></td>
180 <td class="n" id="sq5x4"></td>
182 <td class="n" id="sq6x4"></td>
184 <td class="n" id="sq7x4"></td>
186 <td class="n" id="sq8x4"></td>
188 <td class="n" id="sq9x4"></td>
192 <td class="n" id="sq0x3"></td>
194 <td class="n" id="sq1x3" onmousedown="down_click(1,3)"
195 onmouseup="up_click()"><img src="sym/BlackPawn.png"></td>
197 <td class="n" id="sq2x3" onmousedown="down_click(2,3)"
198 onmouseup="up_click()"><img src="sym/WhitePawn.png"></td>
200 <td class="n" id="sq3x3" onmousedown="down_click(3,3)"
201 onmouseup="up_click()"><img src="sym/WhiteRook.png"></td>
203 <td class="n" id="sq4x3" onmousedown="down_click(4,3)"
204 onmouseup="up_click()"><img src="sym/WhiteKnight.png"></td>
206 <td class="n" id="sq5x3" onmousedown="down_click(5,3)"
207 onmouseup="up_click()"><img src="sym/WhiteQueen.png"></td>
209 <td class="n" id="sq6x3" onmousedown="down_click(6,3)"
210 onmouseup="up_click()"><img src="sym/WhiteBishop.png"></td>
212 <td class="n" id="sq7x3" onmousedown="down_click(7,3)"
213 onmouseup="up_click()"><img src="sym/WhiteKing.png"></td>
215 <td class="n" id="sq8x3"></td>
217 <td class="n" id="sq9x3"></td>
221 <td class="n" id="sq0x2"></td>
223 <td class="n" id="sq1x2"></td>
225 <td class="n" id="sq2x2"></td>
227 <td class="n" id="sq3x2"></td>
229 <td class="n" id="sq4x2"></td>
231 <td class="n" id="sq5x2"></td>
233 <td class="n" id="sq6x2"></td>
235 <td class="n" id="sq7x2"></td>
237 <td class="n" id="sq8x2"></td>
239 <td class="n" id="sq9x2"></td>
243 <td class="n" id="sq0x1"></td>
245 <td class="n" id="sq1x1"></td>
247 <td class="n" id="sq2x1" onmousedown="down_click(-2,1)"
248 onmouseup="up_click()"><img src="sym/WhitePawn.png"></td>
250 <td class="n" id="sq3x1"></td>
252 <td class="n" id="sq4x1"></td>
254 <td class="n" id="sq5x1"></td>
256 <td class="n" id="sq6x1"></td>
258 <td class="n" id="sq7x1"></td>
260 <td class="n" id="sq8x1"></td>
262 <td class="n" id="sq9x1"></td>
266 <td class="n" id="sq0x0"></td>
268 <td class="n" id="sq1x0"></td>
270 <td class="n" id="sq2x0"></td>
272 <td class="n" id="sq3x0"></td>
274 <td class="n" id="sq4x0"></td>
276 <td class="n" id="sq5x0"></td>
278 <td class="n" id="sq6x0"></td>
280 <td class="n" id="sq7x0"></td>
282 <td class="n" id="sq8x0"></td>
284 <td class="n" id="sq9x0"></td>
288 <p id="piece" height="20">:<br>
293 <table cellpadding="5" border="1">
301 <td>Moves (<a href="Betza.html">Betza notation</a>)</td>
315 <td>Can castle with Rook, moving 3 or 4 steps to b- or
388 <td>Promotes to Q, J, R, B, or N on reaching last rank</td>
392 <h3>Pawn peculiarities</h3>
395 <li>Pawns capture differently from how they move (straight
396 move, diagonal capture).</li>
398 <li>Pawns can move two squares ahead from their initial
399 position, provided they are not blocked.</li>
401 <li>On the move immediately after such a double push, they can
402 be captured en passant by another Pawn, as if they had only
403 moved 1 square ahead.</li>
405 <li>Pawns promote to another (non-royal) piece of choice when
406 they reach last rank.</li>
411 <p>A King that has not moved before can move <b>to the square
412 neighboring</b> a Rook that has not moved before, in which case
413 that Rook is moved to the square next to the King on the other
414 side. This is only allowed if all squares between King and Rook
415 are empty, when the King is not in check on the square it came
416 from, and would not be in check on any of the squares it skipped
419 <h3>General rules</h3>
422 <li>It is not allowed to expose your King to check.</li>
424 <li>The game is won by checkmating the opponent's King.</li>
426 <li>Stalemate (no legal moves, but not in check) is a
430 <h3>Differences with FIDE</h3>
432 <p>The Janus pieces are extra, and the board is expanded to
433 accomodate them. The King starts on the other side of the Queen.
434 Castling is asymmetric; the King moves 4 steps on long castling,
435 3 steps on short.</p>
437 <h3>Strategy issues</h3>
439 <p>It is not possible to force checkmate on a bare King with just
440 a single Bishop or Knight (in addition to your own King). Two
441 Knights cannot do that either. The Janus can force checkmate
442 against a bare King.</p>
444 <p>Bishops are confined to squares of a single color. Having
445 Bishops on both colors compensates this weakness, and is worth an
446 extra 0.5 on top of their added value.</p>
448 <p>As Janus is nearly equal in value to Queen, under-promotion to
449 it is common, and there is virtually never any need to promote to
452 <p>The super-pieces (Q, J) devaluate by the presence of
453 lower-valued opponent pieces. As a result trading Q for R + B is
454 in general a good trade when you still have both J, as the latter
455 gain in value by eliminating the opponent's R and B, which is
456 more compensation than the intrinsic value differene between Q
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