For those who know American Football (which is, after all, called a chess match on grass).
A normal chess board is the field, and the pieces are the players. They move per normal chess rules.
First, you set up your offense and your opponent sets up a defense.
The offense players are as follows:
Offensive line = 4 Pawns 2 Receivers = 1 Bishop and 1 Rook Fullback = 1 Knight Halfback = Queen Quarterback = King
The starting "line of scrimmage" is rank 3. A checkers piece is used to designate the ball, with the possessing piece perched atop the checkers piece. For playability, the ball begins in the possession of the quarterback (king).
The opening formation we use is the four pawns in the middle four squares, the bishop and rook on columns 1 and 8 (your choice which goes where) with one on rank 3 and the other on rank 2. The knight and queen must be anywhere on rank 1. The king (quarterback) is on rank 2, just behind the pawn in column 4 or 5, on top of the checkers piece (the ball).
The defense then arranges the same pieces anywhere behind rank 3, except they may not set up such that a non-pawn offensive piece is threatened, and offensive pawns may only be threatened by the defense's pawns.
The offense begins.
Play is just like normal chess, back and forth, one move at a time, capturing pieces as per normal chess rules, with the offense having the additional option on its turn to transfer the "ball" from the currently possessing piece to one of the other (non-pawn) pieces. There is no "incomplete" "fumble" or "interception" (so far - we haven't figured out how to do this without introducing chance - anathema to chess).
The offense's object is to safely get a (non-pawn) piece with the ball to rank 8. Safely means the defense gets its final (virtual) turn - in reality meaning the piece with the ball cannot be threatened (as with regular check, the move into a threatened square on rank 8 with the ball is actually illegal).
Certain football rules are observed - the king may not transfer the ball forward past rank 3, and no other piece may transfer the ball forward, for instance.
It really works, is interesting and fun. Defending is hard and rewarding. The way we play, there is no "calling check" - in other words, the offense needs to spot when its ball piece is threatened. You may play the more challenging way where you need to mate it, but you would have to make laterals (backwards passing the ball from one piece to another after the initial forward pass) illegal. We have not tried that yet.-- globaltourniquet, Mar 21 2008 This seems well thought-out and probably pretty playable. [+]-- imaginality, Mar 21 2008 Why should the king be forbidden to pass the ball forward past the 3rd rank, I would think he should be permitted to throw anywhere on the board, perhaps the remaining pieces should have the ability to throw laterally within the range of their normal movements(pawns 1 square in current rank or back 1, bishop any diagonal back, rook, any side or straight back, knight 3 squares to the side, back or diagonal(semicirle of 3 squares) queen, any pass backwards, and king any pass to any player in any direction for first pass, then equivilent to queen for any other passes.
Can one assume that the ball is "down" when the piece is captured while in possession of the ball?
On further reflection I would wonder why you would capture pieces at all, why not make the object to capture the piece with the ball only, limit movement as per the normal rules. Any "pass" that is received in the last rank or piece that reaches the last rank without capture is a TD, 2nd rack 1stdn, 3rd and back is 2nd, 3rd or 4th etc. Play any # of downs till TD or 4th then play transfers(no kickoff)
Perhaps an interception can occur when one of the non pawn pieces is located in the direct line of the pass(same rank file or diaganol) this works as the only time a good player would make such a pass is by accident or if no other pass is available.
I am also thinking that the King should be permitted a slightly altered movement capability, perhaps maintain 1 square any direction while in possession of the ball, then movement as queen after a pass.
The Pawns present a special problem i think in that they will either capture each other or just sit there. Perhaps if they were allowed to switch places in the same mode as capture(only diagonal, so offensive pawn could switch diagonally with a defensive pawn which would count as 1 move, this would be considered a Blitz but keep in mind then that the pawn that was switched with could now receive the ball and run forward, albeit slowly making this a move to consider carefully.
you might think about this as these adjustments might make the game a bit more strategic(prevent you from just capturing everyone then waltzing in for a score)-- jhomrighaus, Mar 21 2008 //Why should the king be forbidden to pass the ball forward past the 3rd rank,//
This is to match the interdiction against a forward pass past the line of scrimmage, and I think it makes sense.
The interception rule you propose is not very good. I doubt any chess player would accidentally make the transfer without noticing the intervening piece.
We tried the 1st, 2nd, 3rd down thing, but it turns out that defending is hard enough to restrict the offense to one down, then switch.
I like some of your other input, though. The king without the ball movement seems really promising, and more like football, though we tried to maintain the rules of chess movement completely. But that one could be cool. As for no capturing - that might be good, too. But the condition you describe (just capturing everyone then waltzing in for a score) doesn't sem to occur. You still protect your pieces, like in regular chess, so it isn't as though it's that easy for the offense.-- globaltourniquet, Mar 21 2008 //This seems well thought-out//
Then perhaps it isn't appropriate for here?-- globaltourniquet, Mar 21 2008 //This is to match the interdiction against a forward pass past the line of scrimmage, and I think it makes sense.//
Are you intending that the king cannot THROW the ball once he has passed the 3rd rank, or that he MAY NOT THROW the ball to a destination past the third rank?
//The interception rule you propose is not very good. I doubt any chess player would accidentally make the transfer without noticing the intervening piece.//
Perhaps if you assumed that the"pass" takes 1 full turn to complete(ie the defender gets a move in the interim), the "ball" is placed on the square closest to the receiving piece directly in line from the passer, then if the defenders Non pawn piece on his Pass move can land on that square with the "ball" and the receiver cannot capture him it is an interception, if the receiver can capture then it is incomplete and if the defender cannot intervene(or chooses not to) then it is a complete pass) . Additionally you could incorporate direct transfers(handoffs) in which the receiver and the passer are on adjacent squares at which time the pass is instantaneous.
//We tried the 1st, 2nd, 3rd down thing, but it turns out that defending is hard enough to restrict the offense to one down, then switch.//
This makes sense, however if you remove the capture element perhaps the play would proceed more briskly and allow for the use of downs as you would not need to defend your pieces but rather defend the ball. The strategy shifts to a ball centric one rather than all pieces. This would also allow you to move your pieces more freely and broadly when you are not concerned about them guarding another piece or being captured themselves.
Also, are the passes limited to the rank file and diagonal or can they take any angle.-- jhomrighaus, Mar 21 2008 Yes, sorry - the king can't pass it FROM beyond rank 3.
Excellent ideas for the pass rule regarding incompletes and interceptions. I think it just might work. I will try it.
We played that you can pass (or lateral) to any square - you do not need a direct line of squares.-- globaltourniquet, Mar 21 2008 random, halfbakery