# Introducing: FootChess!

Imagine if your chess pieces got bored of their little war games, and decided to play something a bit different. The rules are like Chess except as follows:

1. There is a Ball piece that starts in the center grid intersection, it is treated as being in D4,D5,E4,and E5; whichever piece first occupies any of those squares plays the Ball as if it were in the square they occupy.
2. The Ball is played by any piece 'capturing' it. Instead of being captured, the ball immediately moves as a Neutral piece of the same variety that captured it, under the control of the capturer.
3. If the Ball would capture a piece on this move, it is instead treated as if captured by it. This is called a Pass.
4. Check and Checkmate are not relevant. Instead the game ends by moving the ball into the opposing goal; that being either D0, E0 or D9,E9. Pieces may not occupy these Goal Squares.
5. All pieces may capture opposing pieces as Standard Chess, the exception being that a King may not be captured while on his home ranks, those being 1,2 for White, and 7,8 for Black.
6. The Ball may be played by a pawn through either a capture move into its square, or by a standard move into its square. A pawn may play the Ball to a Capture square even if no Capture exists. Or a standard move sqaure even if there is a piece there. This means a pawn may always play the Ball to a square immediately or diagonally in front of itself, as well as two ranks directly in front of itself, if it is passed to while on its home rank.

That's all the rules, I think it's unambiguous, my friends and I have played at least 4 games, and no further clarifications have been necessary.

I've created a puzzle that uses these rules, based loosely on a position in one of the games with my friends. Your goal is to discover the path to victory. It is White's turn, and someone can win in five or fewer turns.

Disclaimer: Idea possibly stolen from @Alconja, sorry. It was unintentional, but I may have read it late one night and not remembered come morning. We also may have just had similar ideas... ¯_(ツ)_/¯

• is 'fewer than 5 moves' 5 moves between both players, or each player can move up to 4 times each (so a total of 8 moves)? – yitzih Nov 3 '16 at 16:23
• Also can you clarify #3? Does this mean if the ball attempts to capture a piece it becomes possessed by the color of the piece it tried to capture? – yitzih Nov 3 '16 at 16:25
• Are the blacks playing optimally? Do you have to factorise in that they will try and stop you? – Beastly Gerbil Nov 3 '16 at 16:25
• Have I correctly understood that when a pass occurs, the ball is immediately moved again by whichever player it's passed to? – Gareth McCaughan Nov 3 '16 at 16:36
• Both White and Black should be playing optimally, The Ball landing on the square of another piece will act exactly as if that piece had landed on the square containing the ball-- meaning that the Ball should immediately be moved again. – Sconibulus Nov 3 '16 at 16:37

Completed solution, expanded from @Techidiot, and assistance from @DennisJaheruddin and @dcfyj

White Bishop to G2, pass to Rook A8.
Rook must immediately pass;
If rook passes to White Queen, White wins
If rook passes to White Pawn, White puts the ball at B8
Rook can only safely put the ball at B8

Black's turn

Leaving the ball at B8, and not touching pawn A7 allows white to capture ball, promote and win Using rook to capture B8, and put ball at B7, allows white to capture ball with pawn, pass to Queen and win
Using rook A8 to capture A7, and leaving ball at B8, allows white to capture ball with Queen, pass to C8, and score next turn (black can't block)
Using rook D7 to capture A7, and leaving ball at B8, this is more complicated and continued subsequently.
Using rook to capture B8, and put ball at A8, this is more complicated and continued subsequently.

Two options for white's turn

In this case white capture Rook B8 with pawn A7 and promote to Queen. Black has no impactful moves in response, and the new Queen can capture the ball and pass to the other Queen to score. (Credit to user @dcfyj)
White's response should likely be to take a rook. Either Bishop to A8, or Pawn to A7. Credit to @DennisJaheruddin for determining that Bishop to A8 is best

Black's Turn - Credit to @DennisJaheruddin for exploring this

If the Black rook does not move, or moves to C7, White's Pawn can take it, and on White's next either the Pawn or Rook can capture the ball and pass to the Queen for a win
If rook goes to B7, it can be taken by the Bishop, and next turn the Queen passes to the Bishop for a goal, which black cannot prevent.
And if the black rook goes anywhere but A8, the Queen should capture the ball (B8), and put it at C8. This allows the Queen to score next turn which again cannot be prevented. If black chooses Rook to take Bishop A8

White's Move

White has Pawn to B7.

If black leaves the ball, or passes to it to the Queen or Pawn, White wins.
Black can only move to B8 put the ball at A8. In response white pawn takes A8 and promotes to Knight, sending ball to C7. The black rook can only take one of the Knight and the Queen, and the other scores next turn.

• Nice lines, but I don't think they work as well as you hope. If you put the ball on A6 (presumably after promoting to queen), The black rook can capture the queen on C8, which blocks the shot. You're in a much better position, but you haven't won. Also, Black could potentially capture the Pawn at A7 with either rook instead of playing the ball. – Sconibulus Nov 3 '16 at 18:20
• @Sconibulus Thanks for the feedback, I'll double check my work – Angzuril Nov 3 '16 at 18:24
• For the first choice (at the end) White could just capture the Rook at b8 and promote, no? I don't think Black can block anything when that happens. – dcfyj Nov 3 '16 at 19:14
• @dcfyj I initially tried that, but could not find a good place to put the ball. A6 seemed best, but then black will eliminate queen C8. But there could be a combination I'm missing – Angzuril Nov 3 '16 at 19:18
• The way I see it, capture the rook (promote to queen or rook), let black do whatever it wants, use former pawn to pass to queen to shoot for goal. – dcfyj Nov 3 '16 at 19:19

Is this the way -> (Assuming I didn't messed up the rules which I think I did)

Step 1. White Bishop Plays the Ball and hits it towards Black Rook.
Step 2. Black Rook moves it to White Queen.
Step 3. White Queen makes the GOAL!
Note - Step 2 is performed assuming that Black Rook can't pass it to white Pawn.

• This seems to involve the two players cooperating, rather than each trying to frustrate the other's plans. – Gareth McCaughan Nov 3 '16 at 16:30
• @GarethMcCaughan Hahaha :D – Techidiot Nov 3 '16 at 16:30
• Black would be able to pass to the White pawn, in this scenario, and would have no reason to pass to the White Queen – Sconibulus Nov 3 '16 at 16:50
• Sconibus - What if the Black Rook passes it to Pawn and Pawn pushes it diagonally to the block left to White Queen. I think that should be it. – Techidiot Nov 4 '16 at 7:43

Ok, here's what I got

1.Rxa4 Nxg2
2. Bxg2 d5 3. Bf3 Qh3 (Assuming that white doesn't have to pass the ball) 4. Qxa8 Qxf3 And black wins in the next move with Qd1

• Nxg2 is a winning move for black. – dcfyj Nov 3 '16 at 17:20
• Let's call the ball O for notation, 1... Nxg2 goes immediately OxH4, OxF2 OE0# In optimal play by black. – Sconibulus Nov 3 '16 at 17:21