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This page is written by the game's inventor, João Neto.

Swap Chess

Joao Pedro Neto invented this variant and wrote:
I have this simple idea yesterday (Jan 20, 1998) and it's so simple I wonder if it's real new. It was based on the following question: What would happen if I can swap two pieces?

The game, after some modifications on the initial idea, turns out to be enjoyable, with lots of surprises and turnovers (check the sample game).

Rules

1. All FIDE rules apply except in the following.
2. A player can choose in his turn, to make a FIDE move or to perform a swap sequence, respecting the following:
1. To perform a swap, one must be a player's piece P1 (except the King), and the other (any piece) must be at the range attack of P1. Pawns swap as they take, i.e., diagonally forward.
2. P1 can continue the swapping with other pieces.
3. Any piece, except P1, cannot be swapped more than once in a swap sequence.
4. A swap sequence must stop if a check happens.
5. If any pawn reaches, due to a swap sequence, the promotion rank, it is always the player who decides to which piece he promotes.
6. If a pawn reaches his 1st rank, he can move one or two squares forward.
7. The KO rule: a player cannot undo the last swap sequence.

A White Mate-in-One Example

```
. . . r k . . .  8
. . . . . r . .  7
. Q . . . . . .  6
. . . . . . . .  5
. . b . . . . .  4
. . . p . . . .  3
. . . . . R . .  2
. B . . . . . .  1

a b c d e f g h
```
White queen swaps with the white bishop, then with the black pawn promoting it to a knight, then with the black bishop and the black rook, mating Black. The notation would be:

1. 1 Qb6/b1/d3=N/c4/f7++

``` . . . r k . . .  8
. . . . . Q . .  7
. B . . . . . .  6
. . . . . . . .  5
. . r . . . . .  4
. . . b . . . .  3
. . . . . R . .  2
. n . . . . . .  1

a b c d e f g h
```

A Sample Game

```
1.  e2-e4          e7-e5
2.  Nb1-c3         Nb8-c6
3.  g2-g4          Bf8-c5
4.  Qd1/g4/g7/h8

(the 1st swap sequence, Qh8 threats Q:g7)

r . b q k . n Q  8
p p p p . p r p  7
. . n . . . . .  6
. . b . p . . .  5
. . . . O . p .  4
. . N . . . . .  3
O O O O . O . O  2
R . B O K B N R  1

a b c d e f g h

4...               Qd8-h4
5. Qh8/h7/g7/g8+

(white don't mind the mate threath, and start checking)

r . b . k . Q p  8
p p p p . p n r  7
. . n . . . . .  6
. . b . p . . .  5
. . . . O . p q  4
. . N . . . . .  3
O O O O . O . O  2
R . B O K B N R  1

a b c d e f g h

5...               Ke8-e7
6. Nc3-d5+         Ke7-e6
7. Nd5:c7+         Ke6-d6
8. Nc7-b5+         Kd6-e7
9. Qg8/c8/c6/c5+

(the mate threath ended)

r . n . . . b p  8
p p . p k p n r  7
. . b . . . . .  6
. N Q . p . . .  5
. . . . O . p q  4
. . . . . . . .  3
O O O O . O . O  2
R . B O K B N R  1

a b c d e f g h

9...               Ke7-e8
10. Bf1-c4?         Qh4/h2/h1/g1+

r . n . k . b p  8
p p . p . p n r  7
. . b . . . . .  6
. N Q . p . . .  5
. . B . O . p O  4
. . . . . . . .  3
O O O O . O . R  2
R . B O K . q N  1

a b c d e f g h

11. Bc4-f1

(if 11. Ke1-e2 then Rh7/h6/g4/e4+)

11...               Qg1:h2?

(if 11... Rh7/g7/f7/f2/f1+ then Qc5 was lost)

12. Bb5/c6/d7+

r . n . k . b p  8
p p . B . p n r  7
. . p . . . . .  6
. b Q . p . . .  5
. . . . O . p O  4
. . . . . . . .  3
O O O O . O . q  2
R . B O K N . N  1

a b c d e f g h

12...               Ke8:d7
13. Nf1:h2          f7-f6
14. Nh2:g4?

(better 14. Nh2/g4/f6+)

14...               Rh7/g7/g4/h4/h1+

r . n . . . b p  8
p p . k . . N n  7
. . p . . p . .  6
. b Q . p . . .  5
. . . . O . O N  4
. . . . . . . .  3
O O O O . O . .  2
R . B O K . . r  1

a b c d e f g h

15. Qf2/e1/d1/c1/c2  Nh7/f6/g4+
16. Kf2-f3           Nc8/a7/c6/e5+
17. Kf3-g3           h:g7
18. Bd1:g4+          Ne5:g4
19. Kg3:g4           Bg8-e6+

r . p . . . . .  8
p p . k . . p p  7
. . p . b O . .  6
. b O . . . . .  5
. . . . O . K N  4
. . . . . . . .  3
O O Q O . . . .  2
R . O . O . . r  1

a b c d e f g h

20. Kg4-g3          g:f6
21. Qc2/e4/h7+      Ra8/a7/b7/d7

p . p . . . . .  8
p k . r . . . Q  7
. . p . b p . .  6
. b O . . . . .  5
. . . . p . . N  4
. . . . . . K .  3
O O O O . . . .  2
R . O . O . . r  1

a b c d e f g h

22. Qh7:e4          Be6-d5
23. Qe4/c2          Rd7-g7+
24. Kg3-f2          Rh1-f1+

p . p . . . . .  8
p k . . . . r .  7
. . p . . p . .  6
. b O b . . . .  5
. . . . O . . N  4
. . . . . . . .  3
O O Q O . K . .  2
R . O . O r . .  1

a b c d e f g h

25. Kf2-e3          Rg7-g3+
26. Ke3-d4          Rf1-f4
27. d2-d3           Rf4:h4
28. a2-a4           Bb5/d3??

(why? the position seems bad for white!)

p . p . . . . .  8
p k . . . . . .  7
. . p . . p . .  6
. O O b . . . .  5
O . . K O . . r  4
. . . b . . r .  3
. O Q . . . . .  2
R . O . O . . .  1

a b c d e f g h

29. Qc2/d3/e4/d5/c6+ Kb7-b8
30. Ra1/a4/a7/a8+    Be4/d5/c6/a8
31. Qd5-d6+          Kb8-b7
32. Qd6-c7+          Ba8/b7

k . p . . . . .  8
p b Q . . . . .  7
. . R . . p . .  6
. O O . . . . .  5
p . . K p . . r  4
. . . O . . r .  3
. O b . . . . .  2
O . O . O . . .  1

a b c d e f g h

33. Rc6/c7/c8+       Bb7/c8
34. R:c7+            Bc2/d3/e4/c6
35. Qe4/c6+          Ka8-b8

(35... Be4/c6 is illegal because of the KO rule)

36. Rc7:c8++

1-0

final position:

. k R . . . . .  8
p . . . . . . .  7
. . Q . . p . .  6
. O O . . . . .  5
p . . K b . . r  4
. . . p . . r .  3
. O O . . . . .  2
O . O . O . . .  1

a b c d e f g h

```

Written by Joao Pedro Neto.
WWW page created: February 3, 1998. ﻿