# Chess with bouncing and explosion

Consider chess with the following additional rules:

The edges of the board consist of ranks 1 and 8 and columns a and h.

• Bouncing: When a piece goes from a non-edge square to an edge square, it must make another move. Exception: When a piece goes from a rank on the edge to a column on the edge or from a column on the edge to a rank on the edge, it must also bounce, but this can be done only once per turn.
• Explosion: When a piece captures another piece, both the piece that captures, the captured piece, and all pieces that are on a square that directly or diagonally neighbours the square that is captured are removed from the board.
• The goal of the game is to either checkmate or explode the opposing king.

Given the standard initial position on a chess board, can one of the sides force a win?

• So can you have infinite Bouncing? Say a Pawn on the 'a' or 'h' files, what happens when it 'must' move but there are no legal moves? Commented Apr 18, 2016 at 20:22
• What if the king is beside one of the captured pieces? Is that considered a checkmate? A check? Can a king capture a piece?? Commented Apr 18, 2016 at 20:27
• I've played a version of chess where each piece had a special property and I think knights had explosion. It was nasty losing your whole queenside from just one fork. Commented Apr 18, 2016 at 20:40
• @stackErr (1) No. A piece can only bounce once per turn, because it has to go from a non-edge square to an edge square. (2) If the king is beside one of the captured pieces, then he will explode, and hence lose. If the king captures a piece, he'll explode and lose. Commented Apr 18, 2016 at 20:42
• A variant without the bouncing and where pawns are safe from explosions is called Atomic Chess and you can play it online. Commented Apr 19, 2016 at 5:08

A simple way:

White opens with Nh3-g5 threatening Nxf7#. The only way to defend is to play f6 or f5, but then White plays Nf7 and Nxd8# is unstoppable.

• This looks like the way. Very clever! Commented Apr 18, 2016 at 21:34
• Need some time to understand that Nh3-g5 means the knight is bouncing, haha Commented Apr 19, 2016 at 2:07
• Why can't Black play Kxf7? Commented Apr 19, 2016 at 3:03
• @EMBLEM Black is free to explode his own king if he wants, of course, I just don't think that would be very bright :p
– ffao
Commented Apr 19, 2016 at 3:32
• @ffao but if the king has exploded, is that really mate?
– Carl
Commented Apr 19, 2016 at 4:00

Not sure if it's this straightforward:

White opens with e3. He's threatening to move his Queen to h5 and then bounce to f7 (Q->h5->f7) for mate on the very next move, so Black needs to respond with g6 to prevent this. White moves Q->h5->g5 and now threatens mate on e7. Black moves pawn or Knight to f6 to block. White then goes Q->h6->f8 and wins.

Turns out it wasn't that simple. Editing to improve this solution:

I didn't note previously that 1 ... h5 is also a defense against White's mate on the second move. So instead I propose 1. e4 h5 2. Qf3 f6 3. Qa3->e7 for mate.

Edit2: That doesn't work either. Back to the drawing board!

• The queen starts on an edge square, so it can't bounce on its first move.
– f''
Commented Apr 18, 2016 at 21:10
• Black can also respond with 1... h5
– ffao
Commented Apr 18, 2016 at 21:12
• @f'' "When a piece goes form a rank on the edge to a coulumn on the edge or form a coulumn on the edge to a rank on the edge, it must also bounce, but this can be done only once per turn." This makes it sound like the Queen can bounce on her first move. But as other commenters noted, I missed that 1 ... h5 is also a defense. Commented Apr 18, 2016 at 21:17
• Oh, that wasn't there when I first read the problem.
– f''
Commented Apr 18, 2016 at 21:18
• Then your solution also doesn't work because of 1. e3 g6 2. Qh5-g5 Bh6xg5.
– f''
Commented Apr 18, 2016 at 21:23