Slowly Progressive Chess

As Scottish progressive chess, but with the next move list:
1 2 2 3 4 4 5 6 6 7 8 8 ...

A game sample:

Q n . . . . . . | 1. e4
p . p k . . . p | 2. d5:e4
. . . . . . . . | 2. Nc3:e4
. . b . O . . . | 3. Bf4:d1 e5
. . . . . . . . | 4. d3 Bg5:d8 K:d1
. . . . . p . . | 4. K:d8 Nf6:e4:f2+
O O . . . . . O | 5. Ke2:f2 d4:e5 Nf3
R . . . . K r . | 6. g54:f3:g2:h1Q:f1+
                  6. K:f1 c456:b:a8Q
                  7. Kd7 Bc5 f543 Rg8g1++

The slower progressive step allows for more tactical positioning and a game with a better tempo (between progressive and FIDE chess). The move list was made to minimize the first player advantage (it is more fair than the typical 1,2,3... sequence).

Another variant, even slower, uses the following list: 1 2 2 2 3 4 4 4 5 6 6 6 7 8 8 8 (which is also quite fair, regarding first player advantage). Here two game samples:

. . . . k . . N  |  1. e4
p . p . p p p p  |  2. d5:e4
. . . . . . . .  |  2. Nc3:e4
. . . . . . . .  |  2. Bg4:d1
. . . . . . . .  |  3. Nc5:b:d8
. . . . . b n .  |  4. Be2:f1:g2:h1
O . n O . O . O  |  4. Ne6:f8g6:h8
. . B . K . N .  |  4. Nc6d4b3:h1
                    5. b4b5b6b7:a8Q+
                    6. B:a1f3 Nh6f5g3 N:c2++

. . . . . . . . | 1. e4
. . . . . . . p | 2. d5:e4
. k . . . . . . | 2. Bc4:f7+
. . . . p . . . | 2. K:f7 Nf6
. . . . . . . . | 3. d3:e4 Q:d8
. . . . . . . Q | 4. e5 Bc5 R:d8 b5
. O O . . . . . | 4. Be3:c5e7:d8
. . . . K . . N | 4. N:e4:f2:h1 Nc6
                  5. a4:b5 R:a7:a8:c8
                  6. N:d8 Kd7c7:b8 c6:b5
                  6. N,,:h1 Na3:b5a7+
                  6. Kb:a7b6 Ne6f4:g2+
                  7. h456:g7g8Q:g2 Qh3 & wins

DIABALLEX

On each turn, a player can (optionally) do the following, in order:
1: Make two Halma moves.  They must be with different pieces.
   Only one of these is allowed by the first player on the first move.
2: Swap the King with a soldier provided that they are
   in the same line and with no enemy piece directly between them.
   This may be repeated successively with several different pieces.
The King cannot move by any other means.
GOAL - Win by getting one's king into the last row.

abcdefghijklm
   o o o o    1
  . . B . .   2
 . . . . . .  3
. . . . . . . 4
 . . . . . .  5
  . . J . .   6
   x x x x    7
abcdefghijklm

Sample Game (notation: a1^ means king swaps with a1)

abcdefghijklm        Bo                  Jx

   . o . .    1.   ..   f1.h3       h7.i6  d7.f5
  . . o x .   2. h3.i4  j1.h7       j7.j3  f7.h5^
 . . o . x .  3. h1.f3  d1.f1       i6.i2  f5.g4^
. . . J . . . 4. i4.j5  ^j5h7  B wins
 . . . x o .  5
  . . x . .   6
   . . B .    7
abcdefghijklm

This game was inspired by Philippe Lefrançois's Diaballik

Trabsact Sagme Diaries

The roads of attack and the roads of defense seldom lead to the same destiny. Games not obeying this live at the razor's edge: they can be magnificent or broken. [T.Sagme, Meditations]

Election Games (4/4)

SEIRPINSKI COALITIONS

On each move fill a cell with your symbol; then (optionally): (a) move a piece from one large triangle to the corresponding empty cell on another, or (b) to the corresponding empty cell on a neighboring small triangle, or (c) to an adjacent empty cell in the same small triangle.

Two friendly cells in a small triangle win that triangle for the player.
Two won small triangles in the same large triangle win that for the player.
Two won large triangles for a player win the game.

Notation as in SEIRPINSKI ELECTIONS including ‘-’ to represent a move of type (a), ‘:’ a move of type (b), and ‘.’ a move of type (c)

Game sample:

      J’s           B’s  
   ========================
1.  111  -       222   -
2.  331  -       121  222-3
3.  231  -       333  322:3
4.  322  331:2   311  332:1
5.  123  322-1   132  121:3
6.  112  321:3   211  132-3
7.  233  331-2   resign

             j            
            j .            
                          
          .     b        
         j j   . .        
        ___________      
      b \         / b    
     . . \       / b .    
          \     /        
   j     j \   / .     -  
  . .   . j \ / . .   b b

So, this game mixes the election goal with a restricted move feature, so that players may reuse their dropped stones. The game converges to an end, since on every turn, a stone is dropped, and eventually the board is full. When that happens, there is always a winner.

Cubic

A very nice puzzle related to Sokoban. You drag stones horizontally, and when two or more of the same color are adjacent, they disappear. Gravity exists to pull your stones down.

Check http://www.agon.com/doodle/four.html and play online.

IQISHIQI example

[rules]

          J                 J   B
abcdefghijklmnopqrstu      ---------
     x x . . . .        1.  q6  h5
    x . . . . . .       2.  b5  h1
B  x . . . . . . x  B   3.  p5  j7
  . . . . . . . . .     4.  e2  k8
 x . . . . . . x . .    5.  d3  h7,ne
o . . . . . . : x . .   6.  r3  f1,se
 . . . x x . . x . .    7.  k10 p7,sw
  . . . . x . x . .     8.  n9  h9
J  . . x . . x . .  J   9.  m10 o8,w  
    x . . x x . .      10.  
     . . . . . .       11.  0-1
abcdefghijklmnopqrstu

A win with a 7 step move after a lousy play by J

Election Games (3/4)

Perhaps the best game with this concept is to use a larger hexagonal board and to simplify the turns into a 12* progressive mutator:

abcdefghijklmnopq    
    . . . . .     1
   . . . .   .    2
  . . . . . . .   3
 . . .   . . . .  4
.   .   . . . . . 5
 . . . .   . . .  6
  . . . . . . .   7
   . . . .   .    8
    . . . . .     9

Game sample:

     J's        B's
1:  --  e1    q5  e9
2:  h2  i7    i5  m9
3:  f4  m7    h4  n4
4:  b4  p4    d4  l4
5:  g1  k9    m1  i9
6:  i1  m3    n2  p6
7:  k3  g7    d8  h6
8:  i3  f6    k1  j2
9:  d2  f2    h8  k7
10  e5 k5     c3 g9
11  resign

abcdefghijklmnopq  
    j j j b b      
   j j j b   b    
  b . . j j j .    
 j b j b   b b j  
.   j   b j . . b  
 . . j b   . . b  
  . . j j b j .    
   b . b .   .    
    b b b j b    

Election Games (2/4)

Hexagonal boards are very nice to play these games, since they have 3 natural directions.

3-HEXAGONAL ELECTION (121)* progressive mutator

On each move fill any empty cell or cells with your symbol.

In a hexagonal board there are three directions (in the following board, one horizontal and two diagonals). The actual board has some cells removed so that all lines have an odd number of cells (to prevent draws in the ownership of those lines):

abcdefghi  
  . . .    1
 .   . .   2
. .     .  3
 .   . .   4    
  . . .    5

A majority friendly cells in a line win that line for that player.
A majority of parallel lines win that direction for that player.
A majority of directions win the game for that player.

Game sample:
                B's      J's
abcdefghi     ================
  j b j    1.  f2       c1  e5
 .   b b   2.  b4       h4
. b     j  3.  f4  h2   g5
 b   b j   4.  e1       g1  i3    
  . j j    5.  c3       resign


Election Games (1/4)

SIERPINSKI ELECTION

On each move fill a cell or cells with your symbol. The number of stones dropped follows a 121 cycle (ie, one stone, then two stones, then one stone, and so on). In short, we say it uses a (121)* progressive mutator.

Two friendly cells in a small triangle win that triangle for the player.
Two won small triangles in the same large triangle win that for the player.
Two won large triangles for a player win the game.

The notation is, top-triangle = 1; bottom-left = 2; bottom-right = 3;
and largest triangle = 1st co-ordinate down to smallest = 3rd co-ordinate.

Game example:
      J's      B's
1. 111       222 333
2. 213       311
3. 123 231   221
4. 312       211 233
5. 313       212
6. 323 121   131
7. resign

             j
            . .
                            
          j     b
         . j   . .
        ___________          
      b \         / b
     b j \       / j j    
          \     /  
   b     j \   / .     .
  b .   . b \ / . j   . b
            
The name is due to the way committee membership can be fiddled so that a strategically-placed minority can still win an election! The idea and these games by Bill Taylor.

This election principle can be extended to more games (check next posts).

Trabsact Sagme Diaries

Every action closes open doors. [T.Sagme, Meditations]

Royal Hand-Grenade Chess

Same as chess, except there is no direct take allowed, on each move all opposite pieces at King distance are captured, the one who captures the king wins

Sample Game:

1. e3    e6        9. b4:b5   Qc7
2. Bd3   g6       10. Nc3     Bb7
3. d3    Nf6      11. Nd5:de6 d6:d5
4. Nh3   Ng4:h3   12. Ba6:ab7 Qc2:cd1
5. h3:g4 Bd6      13. Rc1:c2  Ra7:a6
6. g3    b6       14. Rc3     Nd7
7. d4    c5:d4    15. resign
8. c4:c5 b5:c4

. . . . k . . r
r . . n . p . p
. . . p . . p .
. . . . . . . .
. O . . . . . .
. . R . O . O O
O . . . . O . .
. . . . K . . R

1-11 REVERSI

The scoring and moves of the game are exactly as at standard reversi,
with the four initial moves in the four centre cells.
From the second turn onwards, each player plays a move for himself, one for his opponent, and another for himself, to constitute his turn.

Game sample:

  =xx==oo=  
1. d4  e4
2. e5  d5
3. e3  d3
4. c4  f3
5. d6  d7
6. e2  b4
7. c5  d1
8. e1  f1
9. g2  h3
10 h1  f4
11 g5  g3
12 a4  g1
13 c1  e6
14 f5  h6
15 h2  b5
16 h4  a3
17 f6  a5
18 d8  g4
19 g6  c8
20 c3  f2
21 b8  g7
22 h8  h7
23 b6  h5
24 d2  g8
25 f8  c2
26 f7  e8
27 b3  b2
28 a1  a8
29 b1  e7
30 c6  a2
31 a6  c7
32 b7  a7

1-0 (35-29)

Final Position:

a b c d e f g h

x x x x x x x x  1
x x x x x x x x  2
x o x x x x x x  3
x o o x x o o x  4
x x o x o o o o  5
x o x o o o o o  6
o o o o o o o o  7
o o o o o x x x  8

Corners are much easier to grab, since players may drop an opponent stone on any valid empty cell. There are much more traps on each turn, and the possibilities for each move are quite large.

Trabsact Sagme Diaries

Sometimes we need to cross doors that may lead to defeat, just to close them behind. [T.Sagme, Meditations]

A IQISHIQI quick match

Oshiqi mechanics with both players playing "x"s.
A player wins if 'o' reaches one of his edges.
Moving "o" to a corner wins.  Lose if unable to move.

          A                 B    A
abcdefghijklmnopqrstu      ---------
     . . . . . .        1.  q6  h5
    . . . . . . .       2.  i6  m10
B  . . . . . . . .  B   3.  h11 r7
  . . . . . . . . .     4.  f5  j11
 . . x x . . . . . .    5.  s8  f7
. . . . x . . . x . .   6.  j9  e10
 . x x . . . . . x .    7.  d7 wins
  . . . . . . . . x     8.
A  . . . x . . . .  A   9.
    x . o . x . .      10.
     . x x . . .       11.
abcdefghijklmnopqrstu
          B

Cross-Hairs

Definition:  A piece is on an enemy line if it belongs to a line of adjacent pieces (of either color or type) between two enemy pieces. A line similarly includes any sequence of adjacent edge cells.

RULES
1.  On each turn, each player must drop a friendly soldier on an empty cell adjacent to any stone AND then, optionally, move any soldier to an adjacent empty cell which is adjacent to any other piece. After each drop and after each move:
1.1   Any enemy soldier not on the edge and belonging to *two* enemy lines is replaced by a friendly King;
1.2   Any enemy soldier on the edge belonging to *one* enemy line is replaced by a friendly King;
1.3   This replacement only happens if the dropped/moved piece participates in one of those enemy lines;
1.4   Kings are never replaced and do not move.
2.  When all cells are occupied, the player with more Kings wins.

 abcdefghijklmnopq
     . . . . .     1
    . . . . . .    2
   . . . . . . .   3
  . . . . . . . .  4
 . . . . . . . . . 5
  . . . . . . . .  6
   . . . . . . .   7
    . . . . . .    8
     . . . . .     9
 abcdefghijklmnopq

Sample Game:

      ooo         xxx    
   ----------------------
1.  i5  --      j4  --    
2.  k3  --      g5  j4h4  
3.  f6  k3i3    k5  h4j4  
4.  e5  i3h4:   e7  --    
5.  l4  h4i3    m5  j4k3  
6.  l2  l4m3    d4  k3l4  
7.  n6  m3n4    c5  e7g7:
8.  l6  l2k3:   h6  l4j4:
9.  a5: f6e7    o7  h6j6  
10  h6: h6i6    h8  j6k7  
11. b4  e7d6:   j6: o7p6
12. q5  n6o7:   c7  g7e7
13. d8  a5b6:   a5  d4c3:
14. d2: d6f6    e9::j6h6
15. g9: d2e3    d6  e7g7:
16. e7  e3f4:   f8: h8i9:
17. h8  f4d4:   j8: h6j6
18. m7  q5o5    m3  i9k9
19. l2  d4f4    n6  m3o3:
20. n2  o5p4:   n8  k7l8:
21. g3  p4o5    q5: q5p4
22. q5: n2m1    h2  n8m9  
23. f2  i3j2    n2: n2m3
24. i1: n4l4    k1 m3n2:
25. n8: i1g1     resign

abcdefghijklmnopq  
    . o . @ #     1
   . o @ o o @    2
  @ . o . o . @   3
 # . o . @ o . @  4
@ @ # @ # @ @ o # 5
 # @ # . x # x @  6
  @ # @ # . # #   7
   # x # x x o    8
    @ # . x x     9
abcdefghijklmnopq

One possible variant would remove the edge rule, turning the board into a hex-torus. This has pros and cons, it simplifies the game but at the cost of some clarity (the board topology would become harder to grasp).

Pentaboard

There is a fairly nice pentagonal board available that is fully symmetric and thus useful for games requiring that. We used an asymmetric 5-sided board for our 5-Y game Gem:

         . . . . .
        . . . . . .
       . . . . . . .
      . . . . . . . .
       . . . . . . .
        . . . . . .
         . . . . .
          . . . .
           . . .
            . .
             .

There is no need to have a fully symmetric one, but it is possible. The board is:

         . . . . .
        . . . . . .      
       . . . . . . .
      . . . . . . . .    
     . . . . . . . . .    
      . . . 4 4 . . .    
       . . 3   3 . .
        . 2     2 .
         1       1

Which is just a dodecahedral cap. The "cut" is to join up so that equivalent cells are identified (the same number represents the same cell).

We can do the same for a heptagonal board...

        . . . . 1           1
       . . . . 2           2 .
      . . . . 3           3 . .
     . . . . 4           4 . . .
    . . . . 5           5 . . . .
     . . . . 6         6 . . . .
      . . . . 7       7 . . . .
       . . . . 8     8 . . . .
        . . . . 9   9 . . . .

Just as before, the numbers indicate identical cells. The centre spot is 5, and the whole thing is a symmetric heptagon with 5 dots per side and a 5-dot radius.

TORAX (part II)

Here is another Torax game, where the blocker wins, but only after much more fight (the board is also larger):

 1. c3g7  b3h7
 2. b7h3  adopt

a   b   c   d   e   f   g   h   i    
---------------------------------    
.   .   .   .   .   .   .   .   .    1

.   .   .   .   .   .   .   .   .    2

.   O   O   .   .   .   .   O   .    3

.   .   .   .   .   .   .   .   .    4

.   .   .   .   .   .   .   .   .    5

.   .   .   .   .   .   .   .   .    6

.   O   .   .   .   .   O   O   .    7

.   .   .   .   .   .   .   .   .    8

.   .   .   .   .   .   .   .   .    9

 3.   e5      e2  
 4.   f2      f3  
 5.   e3      e4  
 6.   f4      g4  
 7.   d2      d3  
 8.   g3     d3e2
 9.  e3f2    e4f3
10.  f4g3     g2  
11.   b5      e7
12.   g5      h5
13.   h4      i4
14.   i5      d5
15.   c5      c6
16.   d4     d5e4
17.  d4e3    f3g2
18.   g1      h1
19.   h9      f1
20.  f2g1     f9
21.   a7      a6
22.   i6      i7
23.  i6a7     a8
24.  h4i5     i9
25.   d6     c6d5
26.   b8     a8b7
27. resign

 a   b   c   d   e   f   g   h   i      
 ---------------------------------    
 .   .   .   .   .   O  _X   O   .    1
                      _/              
 .   .   .   X  _O  _X  _O   .   .    2
              _/  _/  _/              
 .   O   O   O  _X  _O  _X   O   .    3
              _/  _/  _/              
 .   .   .   X  _O   X   O   X_  O    4
              _/               \_      
 .   X   X  _O   X   .   X   O   X    5
          _/                          
 O   .   O   X   .   .   .   .   X_   6
_                                  \  
 X  _O   .   .   O   .   O   O   O    7
  _/                                  
 O   X   .   .   .   .   .   .   .    8
                                      
 .   .   .   .   .   O   .   X   O    9

TORAX

1. Initially both play one or more blocks (O) per turn, or else adopt Blocker. After adoption, the other (X) starts the alternating moves.
2. Alternating play continues as at Quax.
3. The game ends when X has made a connected global loop in any direction; or until this is impossible.

The game has two distinct phases. First there is a poker-like game, where both player drop blocking pieces until one of them accepts the task of Blocker. Secondly, there is a race of connection vs. blocking which, eventually decided if the first phase goes too far. Here is an example of it:

1. d3     b5
2. f5     c4
3. a1     b4
4. b1     adopt block

a   b   c   d   e   f    
---------------------  
O   O   .   .   .   .  1

.   .   .   .   .   .  2

.   .   .   O   .   .  3

.   O   O   .   .   .  4

.   O   .   .   .   O  5

.   .   .   .   .   .  6

The game is quickly decided:

5. e4     d5
6. e5     e6
7. d6     d5e6  
8. e1     e2
9. resign

a   b   c   d   e   f    
---------------------  
O   O   .   .   X   .  1
                        
.   .   .   .   O   .  2
                        
.   .   .   O   .   .  3

.   O   O   .   X   .  4

.   O   .   O_  X   O  5
              \_
.   .   .   X   O   .  6

FAIR CHESS

First player has one move, after which players may play either one or two moves per turn, at their choice.

Both moves of the two must separately be legal FIDE moves for the position faced; there is no enpassant but all other FIDE rules apply.

1       c4         c5  Nf6  
2  b4   Nf3       c:b4 Nc6  
3  a4   g3         a5   e5  
4  N:e5 d4        N:e5  d6  
5  Bg5  d:e5      Qc7  Ne4  
6  Bg2  e:d6      N:d6 Bd7  
7  O-O  Qd4       f6   Be7
8  Bf4  Qd5       Q:c4 Rc8
9  Q:b7 B:d6      B:d6 Qc7
10 Rc1  Qe4+      Kd8  Be5
11 R:c7 Nd2       R:c7 B:a1
12 Nb3  Qa8+      Bc8  Ke7
13 N:a1 Qe4+      Be6  ---
14 Nb3  Bh3 ?     f5   Rc3+ !
15 N:c1 Bf1       f:e4 Rd8
16 resign

. . . r . . . . 8
. . . . k . p p 7
. . . . b . . . 6
p . . . . . . . 5
O p . . p . . . 4
. . . . . . O . 3
. . . . O O . O 2
. . N . . B K . 1
a b c d e f g h

After move 14, White loses the queen and is unable to recover the R vs N advantage.

This chess variant, with a pace equal to Marseillais Chess is indeed quite different. Pieces that are moved inside the same turn do not give extra liberties to each other (each move must be legal according to the initial position at the start of the turn).

RAMBO WALLS (A sample game)

j = jeep:     moves 3 spaces
o = obstacle: can only be entered with a single step
g = grenade:  creates an unfillable gap from a wall
r = rope:     crosses a wall  
a = archway:  creates an unfillable gap from a space    
p = pivot:    turns a wall through 90^ (re-usable)
L = L-wall:   2 units L-shaped
3 = 3-wall:   3 units long

     B            J      
1. -N  GIc      WS  GIk
2. WW  EGc      WW  EGk
3. WW  CEe      SS  CEk
4. NW  Ece      WW  ACk  
5. EE  ACe      EE rDEe
6. EE  Egi      SS jS              
7. EE  DFi      WS  Ikm
8. WE  rN       SE pDk
9. NN  CEn      SE 3Ekn
10 NN 3EGl      EE aHim
11 resign     Powers left: J: [ogL], B: [jogapL]


   A   B   C   D   E   F   G   H   I   J   K   L   M   N
a , - - - - - - - - - - - - - - - - - - - - - - - - - . a
  :                                                   :  
b :   +   +   +   +   +   +   +   +   +   +   +   +   : b
  :                                                   :
c :   +   +   +   +-------+-------+   +   +   +   +   : c
  :               |                                   :
d :   +   +   +   |   +   +   +   +   +   +   +   +   : d
  :               |                                   :
e :-------+-------+   +   +   +   +   +   +   +   +   : e
  :                                                   :
f :   +   +   +   +   +   +   +   +   +   +   +   +   : f
  :               |             B                     :
g :   +   +   +   |   +   +   +   +   +   +   +   +   : g
  :               |                                   :
h :   +   +   +   +   +   +   +   +   +   +   +   +   : h
  :                                                   :
i :   +   +   +-------+   +   +   +   +   +   +   +   : i
  :                                                   :
j :   +   +   +   +   +   +   +   +   +   +   +   +   : j
  :           |                                       :
k :-------+   o   +-------+-------+   +   +   +   +   : k
  :           |   |         J     |                   :
l :   +   +-------|-----------+   |   +   +   +   +   : l
  :               |               |                   :
m :   +   +   +   |   +   +   >   <   +   +   +   +   : m
  :               |                                   :
n ` - - - - - - - - - - - - - - - - - - - - - - - - - ' n
   A   B   C   D   E   F   G   H   I   J   K   L   M   N

Trabsact Sagme Diaries

In the middle lies the virtue of no decision. [T.Sagme, Proverbs]

FLAG GRID

* Object of the game: to take the flag to one of one's own home bases.
* Movement and capture is similar to Lines of Action, with the distance to be moved being EITHER the total number of pieces in the vertical line of the piece to be moved, OR the horizontal line, mover's choice.
* If a piece moves to the uncaptured flag, or captures an opposition piece with the flag, he captures the flag and keeps it until captured.

Initial Setup:

a b c d e f g h i
; . x . . . o . : 1
. x . . . . . o . 2
x . . . . . . . o 3
. . . . . . . . . 4
. . . . F . . . . 5
. . . . . . . . . 6
o . . . . . . . x 7
. o . . . . . x . 8
. . o . . . x . . 9

Game Sample:

    Xs:   Os;
1. b2-d4 i3-g5
2. d4-e4 b8-b7
3. i7-i4 h2-g3
4. g9:g5 g3:g5
5. a3-c3 c9-f6
6. i4-h5 f6-g6
7. h8-f6 g6:e4
8. h5:g5 a7-c5
9. g5*e5 e4*e5
10 f6*e5 c5*e5
11 c3*e5 g1-g3
12 c1-d2 b7-c6
13 d2-e3 resign

a b c d e f g h i
; . . . . . . . : 1
. . . . . . . . . 2
. . . . x . o . . 3
. . . . . . . . . 4
. . . . X . . . . 5
. . o . . . . . . 6
. . . . . . . . . 7
. . . . . . . . . 8
: . . . . . . . ; 9

This is a catch-the-flag game with a mix of Lines of Action. Games are fast and full of tactical measures and counter-measures. There is no great strategic depth but the game is fun. Game by Bill Taylor.

SLIDE-CHESS

1. Each player must on each move do one of:-
 (a) make a regular Chess move; (which includes moving or capturing into or out of either cage).
 (b) move his cage (with any contents) to any empty edge or corner square;
 (c) insert his cage (with any contents) orthogonally into the board, shifting the other cells in line until a cage appears at the opposite edge (which must have been empty).
2.  A player wins by capturing the opponent King
3. No double initial pawn step; no castling.
4. When a pawn reaches the 2nd/7th rank, its mover decides how it promotes.
5. A player may not move his cage twice consecutively.
6. No king must ever be in a cage.

Initial Setup

1         [ ]         1  [] White cage
2    r n b k b n r    2  () Black Cage
3    p p p p p p p    3
4    . . . . . . .    4
5    . . . . . . .    5
6    O O O O O O O    6
7    R N B K B N R    7
8         ( )         8
   a b c d e f g h i

Game Sample (‘>’ means a cage slide):

 1. e5 g4
 2. e1a8 e4
 3. Na8 e8a2
 4. a8d1 Ra2
 5. N:f2 K:f2
 6. d1>d8 a2>i2
 7. d6 d:e5
 8. d:e5 Bc4
 9. b:c4 N:c4
10. b5 Ne3
11. Rd7 i2d1
12. R:d1 N:d1
13. Bb6 d1c8+
14. resign (White cannot recover his material)

Final position:

1                    1
2   r . . . . k n    2
3   p p . . p . p    3
4   . . . p . p .    4
5   O . . O . . .    5
6   B O . . O O O    6
7   . . . K . N R    7
8    (n[ ]           8
  a b c d e f g h i

This chess variant has two main features that provide some fun: (1) the board changes (rows and columns are shifted left/right or up/down) which permits checks, piece pinning and the like, and (2) pieces may move very fast to other board edges via cage movements. Game by João Neto.

Games @ Amazons

Games from the Amazons Indians by the Indigenous Brazilian Games Project

Games @ Knossos

I travelled to Greece, visiting Crete and Athens. At Crete I went at the archaeological site of Knossos. Here I saw this reference (click in the pictures to enlarge):

After that visit, I went to the museum where I caught the game itself:


And a view from above:


Unfortunately nothing more was presented at the museum about the game.

Another Taylor's Ghost

Still another beatiful example of a forced sequence mate with Taylor's Ghost in an Aussie Progressive Chess.

1. Nf3
2. a5 h5
3. e4 Ng5 N:f7
4. d5 Qd7 Qg5 Q:d1+
5. K:d1
6. Nb6 Rh6 Rf6 Rf3 Re3 Re1+
7. K:e1
8. Nh6 Nf5 Nd6 Nb5 Nc3 Nd4 Nc2++

r . b . k b . .
. p p . p N p .
. . . . . . . .
p . . p . . . p
. . . . O . . .
. . n . . . . .
O O n O . O O O
R N B . K B . R

After two forced captures which destroyed the White sequences, Black manages to give a great check-mate with his two Knights.

RAMBO Walls

In the SAS post, the traditional Cul-de-Sac game (check also Quoridor) gets more movement and some extra powers to improve the game dynamics.

Well, after some experiences, the powers got larger and deadlier, so RAMBO Walls appeared. The rules are the same, but the game needs a larger board (13x13) and have some extra powers (each player, initially, gets one of each):

* Grenade (explodes half a wall which cannot be rebuilt)
* Archway (prevents a wall between two cells)
* Jeep (the piece moves 3 times in a single turn)
* Rope (the piece jumps over an adjacent wall)
* L-wall (drops a L-shape wall with 2 half-walls size)
* Pivot (a wall with a friendly pivot in its middle can rotate 90º)
* Obstacle (a cell with an obstacle needs a full turn to cross over)

As in SAS, every power deployment substitutes the typical wall drop.

Taylor's Ghost

In Scottish Progressive Chess there is a killer tactic called Galvin's Ghost. The idea is to leave a position where the next player must check our king in his first move, and so ending his own sequence.

In the Australian version (posted below) there is another type of ghost (let's call it Taylor's ghost), ie, leave a position where the next player must capture in his first move.

Here is a game where that tactic is applied twice (in moves 4 and 6):

1. d4
2. Nc6 N:d4
3. Nf3 c3 c:d4
4. Nh6,f5,h4:f3+
5. e:f3
6. c5 d5 e5 Qb6b3:d1+
7. K:d1
8. Bf5,d3 Bb4 c432 ++

r . . . k . . r
p p . . . p p p
. . . . . . . .
. . . p p . . .
. b . O . . . .
. . . b . O . .
O O p . . O O O
R N B K . B . R

AUSSIE PROGRESSIVE CHESS

Same as Scottish Progressive Chess but a move series also ends as soon as a piece is captured.

A game sample:

1. e4
2. d4 d:e4
3. Qh5d5:d8+
4. K:d8
5. Ke2 c4 g3 Bh3 B:c8
6. e5 Nf6 h5 Nc6 Ke7 R:c8
7. a4 h4 Nh3 Ra3d3d8:c8
8. Nb4 a5 Ke6 Bc5 Ng4 f5 f4 R:c8
9. b3 d3 Rd1 Ba3 B:b4
10 e3 Rd8 e4 Kf5 B:b4
11 d4 d5 f3 f:g4+
12 Ke5 g6 Bc5 Rf8 f3+
13 Ke1 d6,7,8Q,h8,h6 Rd5++

. . . . . r . .
. p p . . . . .
Q . . . . . p .
p . b R k . . p
O . O . p . O O
. O . . p p O N
. . . . . . . .
. N . . K . . .

This is also a slower chess variant than the traditional progressive ones. One capture per turn maximum, will set the attention on tactical positions that can take advantage of that new restriction.

SAS WALLS

Rules like Cul-de-sac but with two moves/turn and a wall drop.
Each player initially, has two archways and one grenade.
* An archway between two squares prevents a wall there
* A grenade explodes a wall between two squares and prevents a wall there
Playing the power replaces the wall movement.

A Game Sample:
                      Joao
   A   B   C   D   E   F   G   H   I   J   K   L  
 a +-------------------------------------------+ a
   |                                           |  
 b |   +   +   +   +-------+   +   +   +   +   | b
   |                 B                         |  
 c |   +   +   +   +   +   +   +   +   +   +   | c
   |                                           |
 d |   +   +   +---#   #-------+   +   +   +   | d
   |                                           |
 e |   +   +-------+   +   +   +   +   +   +   | e
   |               |                           |
 f |-------+   +   |   +   +   +   +   +   +   | f
   |               |   |                       |
 g |---#   #-------+   |   +   +   +   +   +   | g
   |       |   |       |                       |
 h |   +   |   |-------+-------+-------+-------| h
   |     J |   |                               |
 i |   +   +   +   +   +-------+------->   <   | i
   |                   |                       |
 j |-------+   +   +   |   +   +   +   +   +   | j
   |                   |                       |
 k |   +   +   +   +   +   +   +   +   +   +   | k
   |                                           |
 l +-------------------------------------------+ l
   A   B   C   D   E   F   G   H   I   J   K   L
                      Bill

     Joao       Bill      
    --------------------
1.  .S  FHi    NN  FHd      
2.  SW  Fik    EE  DFd      
3.  WW  HJi    EE a@JKi
4.  SS  JLh    NW  CEg
5.  SE  HJh    WW  Eeg
6.  WW  FHh    WW  ACg
7.  EE  DFh    WW  CEe
8.  WW  Cgi    NE  ACf
9.  EW  DGi    EN  Ffh
10  EW g@BCg   NN g@EFd
11. SS  EGb    NN  ACj
12. resign


134* Amazons - Some Notes

Remembering the rules of 134* AMAZONS:

As Amazons but
* Players move 1,3,4,4... friendly Amazons per turn
* Different pieces to move within a turn.
* If 4 different pieces cannot be moved, the player loses.
----------------

Some notes:

It's difficult to know how safe it is to leave holes in the walls of one's territory.

Players should always leave some loose cannons scattered to prevent enemy blitzkrieg construction. Too much friendly pieces together are prone to quick isolation, too few to direct attacks.

There is an interesting strategic tension between going edgewards, where it is easier to make territory but also risks being shut in, or going central where one is safe but has little chance to make territory.  This feature is largely absent from the original game.  It is remarkably similar to Go, though in dynamic form rather than static form.

Initial moves of an actual game (first player is X):

1   a1-b2/m2
2   a5-c5/a3    e1-c3/b3    m1-l2/c2
3   i1-k3/m3    m13-l12/l3  b2-c1/k1    e5-e8/k2
4   c2-d2/d1    c5-e5/b2    a13-c11/l11 i13-j12/k11
5   k3-g3/k3    m5-j8/j11   a9-d6/i11   e13-i13/i12
6   e9-h12/h13  j12-k13/j12 m9-k9/m11   d2-g5/d2
7   i9-h9/h11   j8-g8/g13   e8-e10/g12  d6-c7/g11
8   k9-j8/j9    e5-f6/j10   g5-h5/j7    i5-j5/j6
9   g3-f4/j4    h9-i8/i4    g8-g4/h4    c7-c5/e5
10  j5-k4/j5    j8-h6/j8    f6-c6/g2    h5-d9/i9
11  f4-e3/j3    i8-g6/g5    e10-g7/h7   g4-e6/g5
12  h6-i7/h8    c11-f8/g8   d9-d7/e8    c6-b6/c6

a b c d e f g h i j k l m
. . x # . . . . . . # . .   1
. # # # . . # . . . # o #   2
# # . . x . . . . # # # #   3
. . . . . . . # # # o . .   4
. . x # # . # . . # . . .   5
. o # . x . x . . # . . .   6
. . . o . . x # o # . . .   7
. . . . # o # # . # . . .   8
. . . . . . . . # # . . .   9
. . . . . . . . . # . . .  10
. . . . . . # # # # # # #  11
. . . . . . # o # # . x .  12
. . . . . . # # x . o . .  13
a b c d e f g h i j k l m

Trabsact Sagme Diaries

An attacker searches unseen paths; a defender unseen flaws. [T.Sagme, Proverbs]

Two uncommon progressive variants (2/2)

KIWI PROGRESSIVE CHESS
======================
Same as Scottish Progressive Chess except that mate may be delivered only in a move series with no captures.

Some games:

1. e4
2. d5 Kd7
3. e:d5 Nf3 Bb5+
4. Kd6 Bg4 B:f3 B:d1
5. c4 Nc3 d4 Ne4 #

r n . q . b n r
p p p . p p p p
. . . k . . . .
. B . O . . . .
. . O O N . . .
. . . . . . . .
O O . . . O O O
R . B b K . . R

 1. f3
 2. e5 h5
 3. Bh5 Be6 B:f6+
 4. K:f6 Qh4 Q:h2 Q:h1
 5. d4 d:e Qd5 Q:h1 Qf3 +
 6. Ke6 b5 Bb7 B:f3 Nh6 Bb4 +
 7. c3 c:b4 N:f3 B:h6 B:g7 B:h8 Nc3
 8. a5 a:b4 b:c3 c2 Kd5 Kc4 R:a2 c1Q +
 9. R:c1 +
10. Kd5 R:b2 c6 c5 c4 c3 h4 Rd2 c2 Rd1 +
11. R:d1 +
12. Kc4 Kc3 c1N Nb3 Nd4 Na6 Nc7 Nd5 Nf4 Ng2 #

. . . . . . . .
. . . p . . . .
. . . . . . . .
. p . . O . . .
. . . . . . . p
. . k . . N O .
. . . n O O n .
. . . R K . . .

 1. e4
 2. e5 Ke7
 3. d4 d:e5 Bg5+
 4. f6 e5 Bg4 B:d1
 5. Nc3 R:d1 R:d5 R:d8 R:f8
 6. Ke6 f:g5 Nh6 R:f8 R:f2 R:f1 +
 7. K:f1 h4 h:g5 g:h6 h:g7 Rh5 g8Q +
 8. Ke7 Na6 R:Q:g:b Rh2 R:R
 9. Ne2 Ng3 N:h5 Nb5 N:c7 N:a6 Nc5 N:b7 Kg1
10. K:h4[3] K:e5:e4[4] K:b7[3]
11. K:h7[6] Kc2[5]
12. K:a2...d7[7] a5 a4 a3 a2 a1Q
13. resign

. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
. k . . . . . .
. . . . . . . .
. . K . . . . .
q . . . . . . .

This variant is slower than the Scottish one. The mate restriction adds more strategy to the move sequence, since mates are harder positions to get and so, both players may try different approaches without concerning about annoying Fool's mates.

Two uncommon progressive variants (1/2)

PORTUGUESE PROGRESSIVE CHESS
============================
Same as Scottish Progressive Chess except that all moves within a turn are with different pieces, (castling counts both).

Game example:

 1. e4    
 2. e5  Nf6
 3. Nc3 Nf3 Bc4
 4. Bb4 O-O Nc6 d6
 5. O-O d4  a4 Bd2 Qe2
 6. B:c3 Nd4 c5 b5 a6 h5
 7. N:d4 b:c3 Bb3 Bc1 Rb1 Qf3
 8. c:d4 a5 Bg4 Rc8 Qb6 g6 Kg7
 9. Bb2  c:d4 Rfc1 Kh1 Qe2 f3
10. e:d4 Be6 b4 h4 Rh8 g5 Nh5 Kg6 Rc6 Qc7
11. a:b4 B:e6 B:d5 Ra1 c3 Rb1 Qd2
12. a:b4 d5 R:e6 f5 Nf6
13. B:f6 d4 c:b4 Ra2 Qd3 e:f5+
14. K:f6 Re8 Re3 Qf4
15. b5   Rd1 Rb2 Qf1
16. K:f5 Rb8 Re5 h3
17. b6 Rb5 Rdb1 g3 Kg1 Qd3+
18. Kf6 Q:f3 g4
19. b7 R:d5 Rb2 Q:f3+
20. g:f3 Re2 R:b7
21. R:b7 Re5
22. resign

Final Position

. . . . . . . .
. R . . . . . .
. . . . . k . .
. . . . R . . .
. . . O . . . .
. . . . . p O p
. . . . r . . O
. . . . . . K .

This variant provides more 'natural' games that the typical progressive rules. It is more similar to FIDE chess and, in a sense, captures more closely the army metaphor behind the original chess concept (at a given time, every soldier should be able to move).

Neutral Mutator (part IV)

As noted with NeuY, neu-games can be somewhat smaller than their standard counterparts, and maintain the same level of interest.  This is partly because with many more options per turn, (roughly the square of the number!), the game need not be so lengthy for the same total number of options; and partly because the extra move options mean somewhat less space is required to execute the same strategic plan.

For example, we have found that 9-a-side NeuY is fully as interesting as regular 13-a-side Y.

NeuGonnect: Gonnect is already a very intriguing variant of Go, so this game may almost appear to be gilding the lily!  However, as always, the neutral-stone transformer adds intriguing new ideas to the game, while keeping the essential ideas of the parent game largely intact. In Go-like games, we have found the best option is to count neutral stones as liberties for both opponents.  Also, if two replacements are made on a turn, each must be separately legal in the order played; so that living groups in normal Go are still alive. All the other earlier remarks apply here as well. So as explained, Gonnect might also be played on a smaller board. However, as the 13x13 size already seems an ideal balance between the connection and the Go aspects in the parent game, we suggest that Neu-Gonnect not be reduced beyond 11x11, preferably 12x12.

Rules:
"""""
1) Placement styles as for Neu-games generally.
2) If 2 neutrals are flipped, each must be separately legal in the order played.
3) Captures are as in Go, but neutral stones count as liberties for both players.

Play is compulsory; suicide illegal.  The winner is whoever completes an orthgonally connected chain of stones between two opposite sides.

Some moves of a neu-gonnect game:

   --x----?------o----?--
1.  g7   j10    j7   h8
2.  i9   g9    g9h8  j7
3.  i8   g4     h7   i10
4.  i7   i4     h6   h10
5.  i6   k4    g4i4  g9
6. k4i10 g7     j5   j6
7.  k6   g8    j6j7  h8
8.  k7   l9     k8   k9
9.  j8   l8    l8l9  h7

   a b c d e f g h i j k l m  
1  . . . . . . . . . . . . .  1
2  . . . . . . . . . . . . .  2
3  . . . . . . . . . . . . .  3
4  . . . . . . o . o . x . .  4
5  . . . . . . . . . o . . .  5
6  . . . . . . . o x o x . .  6
7  . . . . . . ? ? x o x . .  7
8  . . . . . . ? ? x x o o .  8
9  . . . . . . ? . x . ? o .  9
10 . . . . . . . ? x ? . . . 10
11 . . . . . . . . . . . . . 11
12 . . . . . . . . . . . . . 12
13 . . . . . . . . . . . . . 13
   a b c d e f g h i j k l m

'o' just created a local deadlock using two neutral stones.
'x' must prevent that the upper enemy group reaches the right edge.
Also, a neutral battle is brooding at the board centre.

We end this article with a great position on a NEUMOKU game (make 5 in-a-row):

i j k l m n o p q r s
. . . . . . . . . . .  -2    (declined 3rd swap)
. . . . . . . . . . .  -1  
. . . . . . . x . . .   0  -x----?------o----?--
. . . . . . . o ? . .   1.  n3  m5     o2   n4
. . . . o x x x x o .   2.  l6  q2     o3   p2
. . . . o x o ? o ? .   3.  o4  p5     m2   q1
. . . x . o x o . . .   4.  n2  n6    n4p2  o2
. . ? . ? . . x o . .   5. q1o2 n2     p4   q5
. . . x . ? . . o . .   6. n2q5 n3     p3   m3
. . . . . . . . . . .   7. n3p5 q5     p1   q3
. . . . . . . . . . .   8.  p0  q6    q5q6  p3
                        9.  l4  k5    m3q3  p2
                       10. p2q2 q1     r2   r3

Neutral Mutator (part III)

Another game that fits nicely with this mutator is Y. The complexity of this game on even quite small boards is amazing:

     abcdefghi    --x---?----o---?--
5       ?          e1  f4   e4  h2
4      x ?         c1  c3   f2  e5
3     x o ?        g1  d4   a1  i1
2    x . o o       b2  g3  h2i1 a1
1   ? x x ? o     c3d4 g1  resigns

'o' must swap (as there is only one empty cell), and though momentarily creating a winning path, must immediately destroy it by exchanging one of his vital stones. But in doing that, 'o' provides a winning path for 'x'.

Neu-Reversi can be played in two ways.

(a) NeuVersi: a neutral stone can be dropped anywhere on the board;
(b) AdNeuVersi: it must be adjacent to some stone(s) of some player(s).

In both games, the playing of a genuine stone must follow reversi rules, and neutral stones can be turned over to the player's colour as if they were opponent stones; and if two neutrals are flipped, both must be legal reversi moves in the order played.  As always, if a player cannot make a legal move he is obliged to pass, and if both are thus obliged to pass the game ends and the count is done.  Note, there is no need for the extra game-end placement default-option rules in these games.

The discoverers have tried both versions, and found them both to have their own intriguing characters, which are noticeably (though not overwhelmingly) different from the parent game.  In general, as with all Neu-games, there tend to appear more strategic plans and tactical resources than with parent games, for the same-sized boards.

Here is an example for NeuVersi :

    --x---?-----o---?--
1.  e3  g7    f3  c4
2.  f4  f6    b3  h8
3.  c5  b4    a4  g4
4.  a2  h4

. . . . . . . .  1
x . . . . . . .  2
. x . . x o . .  3
o o x x x x ? ?  4
. . x x x . . .  5
. . . . . ? . .  6
. . . . . . ? .  7
. . . . . . . ?  8
a b c d e f g h

'x' tries to get the h8 corner in the next turn. However, 'o' moves 4... h4 a8, with the following result:

. . . . . . . .  1
x . . . . . . .  2
. x . . x o . .  3
o o o o o o o o  4
. . x x x . . .  5
. . . . . ? . .  6
. . . . . . ? .  7
? . . . . . . ?  8
a b c d e f g h

if 'x' swaps h8, there will be only one neutral left (a8) which provides no captures. So, the move is illegal and 'x' cannot take the corner. [cont.]

Neutral Mutator (part II)

In these neu-games, the instances of two game plans being executed quite independently of each other, is much more common than in regular games. The neutral structures serve to undermine enemy positions and to create optional paths to the game's goal. It is a very flexible tool.

I realized that this mutator could be used in many more games. But before continuing, as Bill Taylor noted, the rules would not be totally specified unless we say what happens when the board is almost full:

1) When there is 1 space and no neutrals left: player to move fills the space;
2) when there is 1 neutral and no spaces: mover converts the neutral to his own;
3) when 1 of each: mover fills the space, then opponent converts neutral.

As a default option, these end-game rules always apply.

A second experiment was Gomoku. We were surprised to see what a remarkable game was discovered. The complexity and balance of Neumoku seems extraordinary.

NEUMOKU: On a unlimited square board, each player may:
       * Drop a friendly stone plus a neutral stone
       * Flip two neutral stones into friendly stones and then flip another friendly stone into a neutral stone
       The goal is like Gomoku.
       PIE RULE: After the third move, the second player may swap sides.

A sample game:

   --x----?-----o----?--
1.  n3  m5     o2   n4
2.  l6  q2     o3   p2
3.  o4  p5     m2   q1
4.  n2  n6    n4p2  o2
5. q1o2 n2     p4   q5
6. n2q5 n3     p3   m3
7. n3p5 q5     p1   q3
8.  p0  q6    q5q6  p3
9.  l4  k5    m3q3  p2
10. p2q2 q1     r2   r3

Actual Board:

j k l m n o p q r s
. . . . . . . . . .  -1
. . . . . . x . . .   0
. . . . . . o ? . .   1
. . . o x x x x o .   2
. . . o x o ? o ? .   3
. . x . o x o . . .   4
. ? . ? . . x o . .   5
. . x . ? . . o . .   6
. . . . . . . . . .   7

Here, 'o' has a winning sequence:

   --x---?-----o---?--
11.  o5  l5    r7  s1
12.  s7  l3    q4  t0

j k l m n o p q r s t u
. . . . . . . . . . . . -1
. . . . . . x . . . ? .  0
. . . . . . o ? . ? . .  1
. . ? o x x x x o . . .  2
. . . o x o ? o ? . . .  3
. . x . o x o o . . . .  4
. ? ? ? . x x o . . . .  5
. . x . ? . . o o . . .  6
. . . . . . . . . x . .  7
. . . . . . . . . . . .  8

Next turn, 'o' wins at column 'q' or the diagonal from p4 to t0. [cont.]

Neutral Mutator (part I)

Joao Neto has found a most promising new game mutator which seems applicable to a number of games. It is most applicable to games which begin with an empty board and continue with players adding a piece per turn. Obvious examples are: almost all connection games, Go, Go-moku, Reversi. Initially, this idea was meant to create a Hex variant, called Nex (or Neux):

NEX: On a Hex board, at each turn, the player must do one of:
       * Drop a friendly stone plus a neutral stone;
       * Flip two neutral stones into friendly stones and then
          flip a different friendly stone into a neutral stone.
The goal is as for Hex, with a connecting path including no neutrals.  

Here is a sample game:

    Vertical   Horizontal                      
  --v-----?-----h------?--                          
 1. b11   f6    d7     b8
 2. e7    g5    h3     f4
 3. i3    g3    g6     e6
 4. f6g5  a11   d10    h4
 5. f9    d9    g3h4   d7
 6. e4    f3    f4e6   d10
 7. i4    d6    h5     e3
 8. d6d7  g5    e3f3   f4
 9. i5    c4    h7     f8
10. h6    d3    g7     c10
11. d3c4  f6    f8d9   g3
12. i7    b10   i6     b9
13. b9b10 h6    c10b8  f3
14. c8    k5    d5     b11
15. e5    e9    a11b11 b8
16. e9k5  b9    e8     k2
17. j7    k7    j6     j2
18. k6    g4    j5     i2
19. k4    k1    k3     j3
20. j4    g8    i2j2   d5
21. Resign

Final Position:

  a b c d e f g h i j k
1  . . . . . . . . . . ?
2   . . . . . . . . h h ?
3    . . . v h ? ? h v ? h
4     . . v . v ? ? h v v v
5      . . . ? v . ? h v h v
6       . . . v h ? h ? h h v
7        . . . v v . h h v v ?
8         . ? v . h h ? . . . .
9          . ? . h v v . . . . .
10          . v h ? . . . . . . .
11           h h . . . . . . . . .
              a b c d e f g h i j k

These games are full of tactical subtleties. An interesting feature is that no piece is totally useless, because it can always be used to swap two neutrals. Swap battles tend to occur after some critical mass of neutrals is achieved. Forcing moves, (i.e. where the player forces the opponent to drop a piece of their own colour) are a key to success in this game,   as that is the only sure way to stop him flipping two '?'s next turn.

[cont.]

A new tiling for board games?

Anybody seen this pattern used on board games? There is a mix of cells with different connections, some with four connections and others with six. Also, its dual (if you play in the intersections) has three and four connections. This may be a good playing field for games exploiting the compromise between square and hexagonal boards.

Trabsact Sagme Diaries

There's art between the keeping and the releasing. When we talk about desires, this is called wisdom. When we talk about games, this is called mastery. [T.Sagme, Meditations]

Hop Chess

0. Same as FIDE except:
1. On each turn, each player must do both the following actions:
   1.1. Move a friendly chess piece; then
   1.2. Move his hopper to any empty square
2. If a chess piece moves onto a hopper (of either color),
    it must move  again (it's invalid to return to the initial square).
   2.1. Kings cannot move onto a hopper, nor castle across one.
   2.2. If the piece cannot move after the hopper, the move is invalid.
   2.3. If a queen lands on a hopper, it continues with the same type of
    movement that it used to get there (ie, both orthogonal or
    both diagonal moves).
   2.4. En-passant is still possible, but not if either pawn moves twice
3. Initially, the hoppers start off-board.
   White's first move is restricted to a piece move only.
  
Notes
  
* When moving the hopper, the player may place it where it was.
  He does not have to change the place of his hopper every turn.
* Pieces may move over hoppers.
* A piece may execute two hops, if it moves from one hopper to another.
* A hopper extends the moving/capturing range of pieces,
  so a King may be under check via one or both hoppers.
* It is not possible to capture more than one piece per move,
  since hoppers are always on empty squares.
* A pawn may promote onto a hopper and then the player must move
  the promoted piece.

Example   (@ white hopper, # black hopper)

r . b q k b n r    Some valid moves:
p p . . p p p p     Bc8-f5-e4
. . n p . . . .     d2-d4:c5
. . p . . # . .     Nc6-d4-f5:g3
. . . @ . . . .
. . . . . . O .
O O O O O O B O
R N B Q K . N R

A game:

HOP-CHESS
=========
 1. e4         Nf6  d5
 2. d4   d3    e6   b4+  
 3. Nc3  g5    Be7  b4  
 4. B:f6 e5    e:d4 b4    
 5. Q:d4 e5    g:f6 b4    
 6. e:f6 e4    Na6  c5    
 7. f:e7 d5    c:d4 b4    
 8. e:Q+ f3    K:Q  e8+
 9. Nce2 f3    d3   b4    
10. c:d3 c1    Nd4+ e8    
11. Kd2  h3    N:b2 c4+
12. Kc2  a4    Na3+ e6
13. Kb3  c1    Re5  a5
14. Ne4  c6+   Ke8  e3+
15. N:e5 c6    a5   a4+
16. K:a3 b1    b5   b4+
17. B:b5 e1    resign

r . b . k . . .
. . . p . p . p
. . . . . . . .
p B . . N . . .
. # . . . . . .
K . . . . . . .
O . . . . O O O
R . . . @ . N R

Even though the existence of hoppers makes the opening and middle game much more attack-oriented, and also the distant endgame, it dies NOT seem to be the case for most K & P endgames, even with a minor piece or two.  The reason is, that the weaker side can use his hopper to stop the stronger king from ever making a breakthrough into the enemy area, as usually happens in endgames.  So there are SOME games at least that are harder to win in the hopper version. But not many.

Trabsact Sagme Diaries

The way to one's goal often lies in the opposite direction. [T.Sagme, Meditations]

Ataxx

Ataxx & Hexxagon are very interesting games but there doesn't seem to be any strategic element, merely tactics. However, on much bigger boards, there might be some strategy. This variant is a very large game of Hexxagon with a restricted progressive mutator (which speeds and adds depth to the game) and with a more mixed-up start (to allow more flexibility of directions).

===
1344 HEXXAGON

Every move must be from stones already on the board at the start of the turn
===
  abcdefghijklmnopqrstuvwxyzABCDEFG      XXX    OOO
          x . . . x . . . o          1.  v4  n6,m5p4,f6
         . . . . . . . . . .         2.    
        . . . . . . . . . . .        3.    
       . . . . . o . . x . . .       4.      
      o . . . . . . . x . . . o      5.      
     . o . . . o . . . . . . . .     6.        
    . . . . . . . . . . . . . . .    7.        
   . . . . . . . . . . . . . . . .   8.        
  o . . . x . . . . . . . o . . . x  9.  
   . . . . . . . . . . . . . . . .  10.          
    . . . . . . . . . . . . . . .   11.        
     . . . . . . . . . . . . . .    12.        
      x . . . o . . . x . . . x     13.      
       . . . . . . . . . . . .      14.      
        . . . . . . . . . . .       15.    
         . . . . . . . . . .        16.    
          x . . . o . . . o         17.  

Trabsact Sagme Diaries

Let the players be silent, Let the pieces talk. [T.Sagme, Proverbs 3,2]

13(4) progressive mutator

Amazons is another example of a game using the progressive 13(4) mutator. So, the first player makes one move, then the second player makes three moves, and then, on every remaining turn, both players make four moves. There is a restriction (we should always attach restrictions to progressive mutators): a piece can only move once per turn. Here is a board after 7 moves:

a b c d e f g h i j k l m n o p q r s
. . . # y # . . . . . y . . . o . . . 1
. . . . # # . # . . . . . . . y . . . 2
y . . . # . # . . . . . . . . . . . . 3
. # # # # . # . . . . . . . . . . . . 4
. # . . # . . . . o . . . . . . . . . 5
# # . . . . . . . . . . . . . . . . . 6
# . . . . o # . . . . . . . . . . . . 7
. . . # . . . . . . . . . . . . . . o 8
. . . y . . . . . . . . . . . . . . . 9
. . . . . . . . . . . . . . . . . . . 10
. . . . # o . . . . . o . . . . . . . 11
. . . . y . . . . . . . . . . . . . . 12
. . . y . . . . . . . . . . . . . . . 13
. . . . # . . . . . . . . . . . . . . 14
. . . # . . . . . . . . . . . . . . . 15
. . . y o . . . . . . . . . . . . . o 16
. . . # . . . . . . . . . . . . . . . 17
. . . . . . . . . . . . . . . . . . . 18
. . . . . . . . # . . . . . . . . . . 19
a b c d e f g h i j k l m n o p q r s

Moves: Y vs O

1. s4d4/b4
1... a7d7/g4 d19g16/g7 l19l16/i19
2. a8a5/b5 d1d2/d1 d4d3/d4 h19c14/c4
2... h1g2/e2 d7e6/e3 l16l11/e4 a12b11/b6
3. a5a9/e5 d3a3/a7 d2e1/g3 p19p2/h2
3... g2j5/f1 e6f7/f2 b11f11/a6 g16e16/e14
4. a16d16/d17 c14d13/d15 a9d9/d8 s12e12/e11


Quoridor variants

Here are some 2004 Quoridor variants by João Pedro Neto and Bill Taylor.

Four-Way Walls

• One player has stones n s e w, the other N S E W.
• Each stone must try to cross the boundary furthest in its name-direction.
• With 13444 equalizer, in each turn each of a player's stones, (move order at the mover's discretion), must move one orthogonal step; then a wall is played (but not on the boundary); all as in Corridor.
• If any stones are adjacent to the moving stone in its chosen direction, it may jump them to the next vacant cell. If a wall blocks this direction part-way through such a jump, either unblocked right-angle may be turned.
• The winner is the first player to get three stones off the board. 

Sample initial moves:

  A   B   C   D   E   F   G   H   I   J   K
a + - - - - - - - - - - - - - - - - - - - +
  :                                       :
b :   +   +   +   +   +   +   +   +   +   :
  :             s                         :
c :   +   +   +   +-------+-------+   +   :
  :                     W                 :
d :   +   +   +-------+   +   +   +   +   :
  :         S |     e |                   :
e :   +   +   +   +   |   +   +   +   +   :
  :         E |       |                   :
f :   +   +   +   +   +   +   +   +   +   :
  :       |                 N |           :
g :   +   +   +   +   +   +   |   +   +   :
  :       |         n         |           :
h :   +   +   +   +   +   +   +   +   +   :
  :                             w         :
i :   +   +   +   +   +   +   +   +   +   :
  :                   |                   :
j :   +   +-------+   |   +   +   +   +   :
  :                   |                   :
k + - - - - - - - - - - - - - - - - - - - +

   N E S W    wall    n e s w    WALL
   """""""""""""""""""""""""""""
1. - - - W    CEj     e e s -    Fik
2. N E S W    GIc     n e w w    Cfh
3. N N S W    EGc     n e w w    DFd
4. N N W W    Hhf     n e w s    Ddf  
5. N E S N    Fdf

This is a very fun game. Both player must, at each turn, decide which enemy player they want to delay, while advancing their own as far as possible.

§

Endless Fences

• Quoridor rules but with no wall limit

Sample game:

                    Joao

        H   G   F   E   D   C   B   A
        |   |   |   |   |   |   |   |
    +-----------------------------------+
    |                                   |
 1--|   +   +   +   +   +   +   +   +   |--1
    |                                   |
 2--|-------+-------+-------+   +   +   |--2
    |                                   |
 3--|   +   +   +   +   +   +-------+   |--3
    |                   |       |       |
 4--|   +   +   +   +   +   +   |   +   |--4
    |                   |       |       |
 5--|   +   +   +   +   +-------+-------|--5
    |                     O   X         |
 6--|   +   +   +   +   +   +-------+   |--6
    |                       |       |   |
 7--|   +   +   +   +   +   |   +   |   |--7
    |                       |   |   |   |
 8--|-------+-------+-------+   |   +   |--8
    |                           |       |
    +-----------------------------------+
        |   |   |   |   |   |   |   |
        H   G   F   E   D   C   B   A

                    Bill
    JoaO       BilX
-----------------------
1. S [ec8]    W [ec2]
2. W [ge8]    E [gi8]
3. S [ac3]    E [b79]
4. S [ge2]    E [gi2]
5. S [ba5]    N [c68]
6. E [b35]    N [d35]
7. S [db5]    N [ac6]
8. E [a68]    resign

§

Endless Barriers

• Quoridor rules except:
• no wall limit
• walls can also be L-shaped
• player's piece moves twice per turn 

Sample game:

                   Joao
  
   A   B   C   D   E   F   G   H   I   J   K   L
 a +-------------------------------------------+ a
   |   |                                       |
 b |   |   +   +   +   +   +   +   +   +   +   | b
   |   |                                       |
 c |   +-------+-------+-------+-------+   +   | c
   |               |                           |
 d |-------+-------|-------+   +   +---+   +   | d
   |               |               | J         |
 e |   +   +   +   +   +-------+   +   +   +   | e
   |                       |   |       |       |
 f |---+   +   +   +   +   |   +---+   |   +   | f
   |   |                   |           |       |
 g |   +-------+-------+   +---+-------+-------| g
   |                 B     |                   |
 h |   +   +   +---+-------+   +   +   +   +   | h
   |           |                               |
 i |   +   +---+   +-------+   +   +   +   +   | i
   |       |       |                           |
 j |   +   +   +   |   +   +   +   +   +   +   | j
   |               |                           |
 k |   +   +   +   +   +   +   +   +   +   +   | k
   |                                           |
 l +-------------------------------------------+ l
   A   B   C   D   E   F   G   H   I   J   K   L
                         Bill
    Bill        Joao             Bill        Joao
-----------------------     -----------------------
1. .N  FHc     SW  EGi      11. NN  Geg    EE  BDg
2. EW  DFc     WW  Eik      12. NE  Bf3    NN  DFg
3. EE  BDc     WW  Bac      13. EE  Id4    resign
4. NN  ACd     SE  HJg
5. NW  CEd     EE  HJc
6. NW  EGd     EE  Gg4
7. SW  Ece     ES  EGh
8. WW  FHe     ES  Dh4
9. SW  Hf1     ES  Ci4
10 SW  Jeg     WW  JLg

 

§ 

[addendum: variant by neto and Taylor from 2010]

Assassins

• Move sequence 012(122)* with passing options on all parts.
• number xyz means x moves of the King, y moves of the Assassin, place z connected walls
• Basic corridor rules with each having a king and an assassin.
• No player may move so as to permanently separate an assassin from its target king. If a piece is unable to move, it stays still.
• The first player to kill the opponent king (by replacement), wins.
• Assassins may not be captured. 

      a   b   c   d   e   f   g
  +-------------------------------+
  |                               |
7 |   +   +   +   +   +   +   +   |
  |     J                   j     |  CAPS are KINGS,
6 |   +   +   +   +   +   +   +   |  lowercase are assassins.
  |                               |
5 |   +   +   +   +   +   +   +   |
  |                               |
4 |   +   +   +   +   +   +   +   |
  |                               |
3 |   +   +   +   +   +   +   +   |
  |                               |
2 |   +   +   +   +   +   +   +   |
  |     B                   b     |
1 |   +   +   +   +   +   +   +   |
  |                               |
  +-------------------------------+
      a   b   c   d   e   f   g 

     B  b    X       J  j    X
     ===========================  
1.   -  s   a1+1     n  w   g5+2    (a1+1 means first quadrant at corner a1)
2.   e  ws  b3+3     w  se  e4+1
3.   e  es  d1|      s  nn  e1+4
4.   w  ww  e3|      w  nn  d3+1
5.   e  nw  c6+3     w  sen c4+1
6.   w  nw  d6-      w  ee  b7+4
7.   e  ss  f6-      w  en  d7-
8.   w  sw  b1|      resign

      a   b   c   d   e   f   g
  +-------------------------------+
  |                               |
7 |   +   +---+-------+   +   +   |
  |       | B                     |  CAPS are KINGS,
6 |   +   +---.-------+-------+   |  lowercase are assassins.
  |           |               | j |
5 |   +   +   +   +   +   +---'   |
  |           |       |           |
4 |   +   +   +---+   +---+   +   |
  | b             |   |           |
3 |   +---.   +   +---|   +   +   |
  |       |           |           |
2 |   +   +   +   +---+   +   +   |
  |   |   |       |               |
1 |   `---|   +   +---+   +   +   |
  |     J |           |           |
  +-------------------------------+
      a   b   c   d   e   f   g