4 ms·

Over the years my friends and I have come up with some variants, with varying degrees of fun/sanity. 1) Start with all pieces off the board. To make a move, yo

by thom 7y ago

Over the years my friends and I have come up with some variants, with varying degrees of fun/sanity. 1) Start with all pieces off the board. To make a move, you can either put a piece onto your half of the board, or move an existing pieces. Captured pieces cannot be reused (or maybe they can, if you want some sort of bughouse variant). 2) Put a sticker under one pawn on each side. These are the 'assassins'. Be sure to randomise your pawns without looking at their bases. During the game, as a move, you may turn over one of your opponent's pawns - if it is the assassin, you may choose to reveal it. If you do, you now control that piece as if it's your colour and may move it immediately. This of course means you have a 1/4 chance of the opposing king being in check, in which case you can capture it and end the game right there. 3) Ghost pieces. Whenever a piece is captured, remember the square on which it died - it now haunts this square. Any time during the game, a ghost piece may make any capturing move from its square, but instead of capturing the opposing piece, it merely frightens it. Frightened pieces can't move during your opponent's next turn. 4) Tunnels! Cut out some cardboard or paper in a randomish shape to overlay any number of squares in the middle of the board. This represents rock, into which pieces cannot move. The first move a piece makes into the rock weakens it. The second clears the rock out of the way (keep a pair of scissors handy). Some of this seemed like a good idea at the time.

JadeNB 7y ago
I like your (1) and (2), although (3) and (4) seem like the sort of bookkeeping that could only be fun if you had a computer to keep track of them. > 1) Start with all pieces off the board. To make a move, you can either put a piece onto your half of the board, or move an existing pieces. Captured pieces cannot be reused (or maybe they can, if you want some sort of bughouse variant). Can a piece be moved into any unoccupied position on your half of the board, or only its usual starting position? Can this be done when your king is in check (in hopes of blocking the check)? > This of course means you have a 1/4 chance of the opposing king being in check, in which case you can capture it and end the game right there. I think I don't understand this. The Wikipedia page doesn't seem to describe the starting set-up, but I guess it's the usual one for chess. Are you referring only to the first move? (Otherwise it seems to me that the chance of check depends in an extremely complicated way on the game so far.) In that case, I agree that there's a 1/4 chance of one of the pawns that could check the king being the assassin, but you still have only a 1/2 chance of picking that pawn correctly (even if it's there), so it seems more like a 1/8 chance to me.
- thom 7y ago
  You can move to any unoccupied position in your half in (1). We didn't analyse it deeply tbh, mostly we'd just build an ultra-castle of some sort. And yes, you can put in a new piece to block check. We didn't initially realise this, but the king should be the first piece played, or obviously some smart alec will just leave it off the board. With the assassins, yes it's just a normal setup. But if your first move as white is to turn over the black d7 or f7 pawn, and one of those is the assassin, then you get to take the king. If they're normal pawns, you've spent the move, setting you back in development. Probability-wise I just mean there's a 2/8 chance that it's one of these pawns.
  - JadeNB 7y ago
    > Probability-wise I just mean there's a 2/8 chance that it's one of these pawns. Right—there's a 2 in 8 chance that the assassin is one of those pawns, and a 1 in 2 conditional probability, given that one of them is the assassin, that the one you pick is the assassin; so, by 'deconditioning', a 1 in 8 chance overall. (I think it might make this more plausible—just in terms of probability, not a better rule—to imagine that the rule is changed so that the assassin has to be one of the pawns who can check the king. Then the probability of one of those pawns being the assassin is 100%, by fiat; but you've still only got a 50% chance of picking that one.)
    - thom 7y ago
      Yup, this is correct. Apologies for the reckless use of numbers!
  - V-2 7y ago
    "Probability-wise I just mean there's a 2/8 chance that it's one of these pawns" Unless I misunderstood the concept somehow, your calculation seems to be, as the great GM Finegold would put it, "incorrect!" How many ways are there to pick 2 pawns out of 8? (8x7)/2, or 28. How many ways are there to pick 2 pawns out of 6? (6x5)/2, or 15. In other words, there are 28 combinations in total, and only 15 combinations where NEITHER of the 2 crucial pawns is an assassin. This means the actual probability is (28-15)/28, or 13/28, or about 46% (rather than 25%). Let's do a sanity check. "Safe" combinations: ab ac ae ag ah bc be bg bh ce cg ch eg eh gh 15. "Unsafe" combinations: ad af bd bf cd cf de df dg dh ef fg fh 13. Yup, math works out.
cwmma 7y ago
I used to play a variant where captures were not announced so the only hint that you lost a piece was when you tried to move it and were informed that that wasn't a legal move
m12k 7y ago
Your variant 1) reminds me of the board game Hive. It feels like a hex-based, lightweight mix between Chess and Go (you win by surrounding your opponent's Queen Bee) where the pieces also create the shape of the board.
CYHSM 7y ago
Regarding number 4) this seems very similar to the board game Stratego [1] where part of the squares can not be stepped on. Also you only see your opponents pieces when you attack! [1] https://en.wikipedia.org/wiki/Stratego https://en.wikipedia.org/wiki/Stratego

by thom 7y ago

JadeNB 7y ago

I like your (1) and (2), although (3) and (4) seem like the sort of bookkeeping that could only be fun if you had a computer to keep track of them. > 1) Start with all pieces off the board. To make a move, you can either put a piece onto your half of the board, or move an existing pieces. Captured pieces cannot be reused (or maybe they can, if you want some sort of bughouse variant). Can a piece be moved into any unoccupied position on your half of the board, or only its usual starting position? Can this be done when your king is in check (in hopes of blocking the check)? > This of course means you have a 1/4 chance of the opposing king being in check, in which case you can capture it and end the game right there. I think I don't understand this. The Wikipedia page doesn't seem to describe the starting set-up, but I guess it's the usual one for chess. Are you referring only to the first move? (Otherwise it seems to me that the chance of check depends in an extremely complicated way on the game so far.) In that case, I agree that there's a 1/4 chance of one of the pawns that could check the king being the assassin, but you still have only a 1/2 chance of picking that pawn correctly (even if it's there), so it seems more like a 1/8 chance to me.

thom 7y ago
You can move to any unoccupied position in your half in (1). We didn't analyse it deeply tbh, mostly we'd just build an ultra-castle of some sort. And yes, you can put in a new piece to block check. We didn't initially realise this, but the king should be the first piece played, or obviously some smart alec will just leave it off the board. With the assassins, yes it's just a normal setup. But if your first move as white is to turn over the black d7 or f7 pawn, and one of those is the assassin, then you get to take the king. If they're normal pawns, you've spent the move, setting you back in development. Probability-wise I just mean there's a 2/8 chance that it's one of these pawns.
- JadeNB 7y ago
  > Probability-wise I just mean there's a 2/8 chance that it's one of these pawns. Right—there's a 2 in 8 chance that the assassin is one of those pawns, and a 1 in 2 conditional probability, given that one of them is the assassin, that the one you pick is the assassin; so, by 'deconditioning', a 1 in 8 chance overall. (I think it might make this more plausible—just in terms of probability, not a better rule—to imagine that the rule is changed so that the assassin has to be one of the pawns who can check the king. Then the probability of one of those pawns being the assassin is 100%, by fiat; but you've still only got a 50% chance of picking that one.)
  - thom 7y ago
    Yup, this is correct. Apologies for the reckless use of numbers!
- V-2 7y ago
  "Probability-wise I just mean there's a 2/8 chance that it's one of these pawns" Unless I misunderstood the concept somehow, your calculation seems to be, as the great GM Finegold would put it, "incorrect!" How many ways are there to pick 2 pawns out of 8? (8x7)/2, or 28. How many ways are there to pick 2 pawns out of 6? (6x5)/2, or 15. In other words, there are 28 combinations in total, and only 15 combinations where NEITHER of the 2 crucial pawns is an assassin. This means the actual probability is (28-15)/28, or 13/28, or about 46% (rather than 25%). Let's do a sanity check. "Safe" combinations: ab ac ae ag ah bc be bg bh ce cg ch eg eh gh 15. "Unsafe" combinations: ad af bd bf cd cf de df dg dh ef fg fh 13. Yup, math works out.

cwmma 7y ago

I used to play a variant where captures were not announced so the only hint that you lost a piece was when you tried to move it and were informed that that wasn't a legal move

m12k 7y ago

Your variant 1) reminds me of the board game Hive. It feels like a hex-based, lightweight mix between Chess and Go (you win by surrounding your opponent's Queen Bee) where the pieces also create the shape of the board.

CYHSM 7y ago

Regarding number 4) this seems very similar to the board game Stratego [1] where part of the squares can not be stepped on. Also you only see your opponents pieces when you attack! [1] https://en.wikipedia.org/wiki/Stratego https://en.wikipedia.org/wiki/Stratego