Proposed Rule Change - King Capture

PROPOSED RULE CHANGE: KING CAPTURES

I've been doing some thinking, and I propose a change to the king capture rules.  This may sound controversial, but I believe king captures should NOT be allowed.  I know it's an exciting part of the game (perhaps because king captures can never happen in regular chess), so the purpose of this post is to spark discussion around the topic.  In my opinion, no rule change should occur unless and until the admin team issues a notice of proposed rule change and solicits comments and feedback for a sufficient period of time.  If you're wondering what inspired this post, here's a link (https://www.chess.com/variants/self-partner/game/69626076/45/2) to a game I recently lost when my opponent captured my king even though his own king was in checkmate.

As it currently stands, players are allowed to capture their opponent's king even when their own king is in check.  The current rules break three holy grails of chess:

1. A player must address a check threat on their turn.
2. A checkmated player loses the game.
3. The king cannot be captured.

Proposed Rule: Players must address a king capture threat (all other moves are illegal).  If a player cannot make any move that would prevent a king capture, the game ends in stalemate.

Similar to how a player must (1) address a check threat and (2) acknowledge a pin threat and not move the intermediate piece, players should do everything they can to prevent a king capture.  All their other moves should be frozen/illegal until they address the king capture threat.  This change would not be unprecedented, as there are other situations where pieces are frozen in chess (e.g. when a king is in check, all other moves are frozen/illegal; blocked pieces cannot move; pinned pieces cannot move; etc.).  

In chess, stalemate occurs when a player cannot avoid an impending king capture on the next turn.  Even when pieces are pinned and would otherwise have legal moves but-for the pin, the game ends in a draw.  Similarly, in 4PC, players should not be allowed to let their king be captured.  Thus, when a player cannot prevent an impending king capture threat, the game should end in stalemate.

In the event that this Proposed Rule is not implemented, I propose the following Alternative Rule.

Alternative Rule: Players cannot capture their opponent's king when their own king is placed in check.

The current rules have two moves that are effectively game-finishers: (1) checkmate and (2) king capture.  If players cannot checkmate their opponent when their own king is in check, why should they be allowed to capture their opponent's king under the same circumstances?  I believe the two game-finishers should be treated equally.  

Counterargument #1: A forced king capture is a tactical masterpiece that merits a win.  I agree here (it sure is a thing of beauty).  If you want to effectively call a forced king capture checkmate instead of stalemate, I don't think this better comports with the rules of chess, but I’d be fine with this change as well.  I just do not think an unforced king capture is sufficiently akin to a checkmate such that it should also merit a win.

Counterargument #2: King captures add a unique, exciting tactical element to 4PC.  I also agree here.  If the object of 4PC is to break free from the reigns of regular chess and come into its own, that’s completely fine!  However, if the object of 4PC is to become a fun chess variant that also stays true to its 1000+ years of tradition, then I believe this proposed rule is a necessary change that best accomplishes this objective.

DISCLAIMER: I have never played FFA seriously, so the aforementioned rule change should apply to FFA only to the extent that it would make sense.

Actually, if you are checking a king on your turn. This means that they are checkmated in standard chess. Since the definition of checkmate is no legal moves ( it is illegal to move your king into check). What I’m saying is that since in checkmate you would have to move your king to a square it would be checked, if this were to happen it would be check on your turn. Therefore when the king is in check on an opponents turn they must be able to capture the king or checkmate does not exist. Capture the king is an important rule in 4pc anyways as it no only provides sharp tactical ideas but keeps rules simple and aligning with each other. Removing this rule would also make it illegal to move a piece on a square where a king is. Meaning people could block pieces for a turn with their king.

Hi Puzzles,

I disagree with your two premises:

1) When you check a king on your turn, that means you have checkmated your opponent. In regular chess, you will never check a king on your turn. Checkmate happens after you move (after your turn).

2) Removing the king capture rule would make it illegal to move a piece on a square where a king is, meaning people could block pieces for a turn with their king. This is simply incorrect. I am not arguing that we should allow kings to walk into check. That would be absurd. Rather, I'm arguing the opposite: that there should never be a situation in which a king capture can happen because kings would not be allowed to walk into the line of sight of a king capture threat.

Hey, I wasn't clear with the first point you addressed, what I meant to say is that when a player in 2 player chess is in checkmate, if they would move their king to any square they could, it would still be in check. Which is what checkmate means. After doing this their king would still be in check but it would be their opponents turn. Now if their opponent isn't allowed to capture the king here the king can just escape. We want to keep this constant right? Well in 4 player chess, teams, FFA etc, this is more likely to happen due to different players having a turn cycle. I believe that king capture keeps this turn cycle fair and being exposed to a king capture threat shouldn't be check because the other player is not forced to reveal the attack on your king.

"Now if their opponent isn't allowed to capture the king here, the king can just escape" - this is the part where we disagree.

1) Checkmate is not dependent upon being able to take the king. I am not saying that the opponent shouldn't be allowed to capture the king. That is utterly ridiculous. What I am saying is that if there is a king capture threat, the player should be FORCED to address the threat.

2) The definition of checkmate has nothing to do with whoever's turn it is.

"Capture the king is an important rule in 4pc anyways as it not only provides sharp tactical ideas but keeps rules simple and aligning with each other."

3) I understand that you like king captures. So do I. It absolutely provides amazing tactical ideas.

4) However, it does not keep the rules aligning with each other. King captures are not part of regular chess. In fact, chess is premised on the king not being taken. That is the whole purpose of pins and stalemate.

"Being exposed to a king capture threat shouldn't be check because the other player is not forced to reveal the attack on your king."

5) This is a legitimate point and goes to the crux of my thesis. I believe avoiding king captures reigns supreme. Players should be forced to address a king capture attack, just as a players are forced to address checks. Removing this freedom from players, I believe, is not as antithetical to chess as allowing king captures, which so many rules of chess purport to avoid (illegal moves, pins, stalemate, etc.).

That's a weird proposed rules, but let's see whether it works out in regular chess.

Here's an example:

According to your proposed rules, White has a mate-in-1 by playing Qb7, which is a checkmate (I don't know why this is a checkmate when the King is not be able to capture, can Black just take the Queen and get a draw?).

This looks really weird for a normal chess player. Is Black pinning the Queen? Qb7 should be illegal. But according to the proposed rules, it is legal.

In your self-partner game, I think you have broken the 4th rule of chess: You cannot put your own King into check.

Maybe you have made a huge blunder in your self-partner game.

Hi Dan-Kyu_System,

1) Perhaps you misunderstood my proposed rule. Qb7 should never be legal in that position. I read your post several times and cannot understand how it relates to my proposed rule.

2) Yes, I did not know that my opponent could capture my king while their own king was checkmated. I wouldn't consider it a blunder; rather, my intuition of the rules was incorrect. If I had known my checkmated opponent could still capture my king, I would've obviously played a different move.

3) Here's how my proposed rule would've applied to my game: on 11.b (last move), Blue should be forced to either block the diagonal or move his king off the diagonal. All other moves should have been illegal. The move I played (bxc9) should not have been a legal move.

I get the idea. There are a few things I want to add. You say how should it be possible to be in check and then be able to take the king? I can turn that around, how are you able to check me while you are basically checkmated? To make things clear, a king capture is in my opinion a checkmate! In my opinion the rule of king captures should stay as it is. The reason for that is that in normal chess, you don't abord the game if a forced mate exists. That way you shouldn't abord the game too if you have a forced king capture. Its really hard to explain so just tell me if you want me to explain it in more detail, but I hope you get my idea this way

sounds like a skill issue to me

for all our sakes please paraphrase.

Hi RealMoxile,

I see your point. It's an excellent point. You're saying a forced king capture is basically checkmate, correct? I love king captures, and I think they add a fun element to 4PC. However, king captures are not a part of regular chess. If we want to make 4PC fun and unique, then I think king captures are an amazing addition. However, if we want to make 4PC more similar to regular chess, I think it would be better to remove king captures entirely. I have two statements to make in response:

1) I think a FORCED king capture is more similar to stalemate than checkmate simply because in a forced king capture, the king isn't under an immediate attack (similar to stalemate).

2) I think an UNFORCED king capture should not be equivalent to a checkmate because a checkmate is a really dominant position. When a player is checkmated, he cannot avoid check by moving any one of his pieces. By contrast, in an unforced king capture, the threat can be avoided with a single move.

Hi MistakeEraser,

Please elaborate next time, rather than quote the entire original post. Also, please read the post in its entirety before throwing out insults. Lastly, please check the player's ratings before belittling his skill level. If you did any of the above, you likely would have shared a more productive post.

You're a few years late. There were many threads on this topic in late 2019. I've always been a big proponent of this rule and I pushed for it to be implemented.

It seems to me that the reason this rule bothers you is because it "disagrees" with standard chess as king captures are not a thing in chess.

Well, neither is the color red and blue.

4pc is it's own game. It was born from chess and is based on chess in nearly it's entirety, but it is a modern game, and we have the benefit of tweaking the rules to make it a consistent game, something chess isn't afforded. Hence the starting position has been tweaked, this king capture rule has been implemented, etc. The goal should always be rule consistency and smooth gameplay, it should not be trying to make an exact replica of standard chess at the cost of the aforementioned.

That doesn't mean we should create random rules. Imo we should share everything with standard chess until there is a necessity to tweak something based on the game differences.

Much discussion was made on why this rule was a necessity in 2019. I'll summarize, king captures must precede checkmate as the law of move order dictates the king that is captures dies before the king in checkmate.

A scenario where this can happen is unique to 4pc and can never occur in standard chess, hence there is no rule as such in standard chess.

With that being said, the discussion has always been on whether a king in check or checkmate can capture an opposing king if given the option, not if you should be forced to respond to a king captures threat. 

Essentially with the current rules you are indirectly forced to respond to avoid king captures, but you are not directly forced to respond as you would be if you were put in check. 

The question becomes if a king captures threat is identical to a regular check. While both of them threaten to capture the king next turn, I would argue they are not identical. As someone in the thread said earlier, Player B having the choice to reveal the threat from Player A makes this far more complicated than a direct check. Because of the indirect nature of this threat I think the current rules of not forcing a response but allowing a king captures satisfy as much consistency as possible given this scenario.

it's a feature of the game, not a bug

I mean at least be nice about it, @reysbull at least took the time to explain it instead of completely missing the point

Hi reysbull,

Thank you for your post. It was excellent. You characterized my position correctly, then proceeded to substantiate many great arguments. Below is my response.

Move order: Can you please explain why the "law of move order dictates [that] the king that is capture[d] dies before the king in checkmate?" I actually think the law of move order mandates the opposite. When a player is checkmated on his turn, the law of move order dictates that the game ends at that moment. Why would the law of move order allow a checkmated player to use this turn to capture an opponent's king? The game ends at checkmate; playing past checkmate is absurd. King captures in checkmate actually violate the law of move order. Checkmated players aren't even allowed to checkmate their opponent, so why would they be allowed to use their turn to capture their opponent's king? When a checkmated player captures an opponent's king, the king capture necessarily happens a turn AFTER the checkmate. The law of move order does not dictate the super-priority of king captures; it mandates the opposite.

Viability of king captures: One fundamental principle of chess is that the king cannot ever be captured. Why can't players hang their king, but they can hang every other piece? Why can't players sacrifice their king, but they can sacrifice every other piece? Why can't player's move pieces that are pinned to their king? Why is stalemate a draw? Why must players immediately move their king out of check? If king captures were allowed, every one of these rules would be moot. The reason these rules are in place is that the rules of chess do everything in their power to avoid a situation where a king could be captured. I believe 4PC should do the same. If king captures were equivalent to checkmate in standard chess, why have those aforementioned rules? If the progenitors of chess wanted to make king captures a viable path to victory, they could have easily done so. Instead, they established multiple rules, all aimed at preventing king captures at all costs. These rules ensured that the only viable path to victory is through checkmate (or resignation, of course). Not only would the progenitors of chess disagree with the decision to make king captures a viable winning method, but they would also scoff at the decision to give king captures super-priority, even over checkmate and even in violation of the 4PC move order rule. Forcing players to address unforced king capture threats aligns more with the rules of standard chess than allowing king captures as a viable path to victory. Allowing king captures in one context but respecting the necessity to avoid king captures in other contexts (e.g. check, pins, can't hang/sacrifice the king, etc.), is quite inconsistent.

2019 Discussion: I understand this discussion may have already happened, but I believe the wrong decision may have been implemented. I understand that 4PC is its own game with new implementations, but I don't believe it should stray so far from its roots as to violate such a fundamental bedrock of its predecessor: disallowing king captures at all costs.

I assume the whole idea of "checkmate" exists because there is no need to continue the game if the king has no legal moves and people back then were too lazy to play out one more move. But in reality, if checkmate didn't exist, then the game would end by king capture. So technically, if a discovered check were revealed on a player (in a 4pc game, obviously), that king has no legal moves because it is not even his turn, and thus on the next turn his king will be captured. In some sense that's why I think the rule exists. It is consistent with the rules of chess if you really think about what "checkmate" actually means. I could be wrong, but that's just my stance on this matter.

"Move order: Can you please explain why the "law of move order dictates [that] the king that is capture[d] dies before the king in checkmate?"

Think of a standard chess position with your king in check, can you deliver checkmate? No, because of the law of move order, you would first have to react to your own king in danger before delivering checkmate.

As you hanged your king in your game, you have been put in check retroactive to the previous move, and now this move you are the one whos king is available for capture, nullifying all other threats you made towards an opposing king.

"Viability of king captures: One fundamental principle of chess is that the king cannot ever be captured. Why can't players hang their king, but they can hang every other piece? Why can't players sacrifice their king, but they can sacrifice every other piece?"

This is the paradox of what is happening in your game. You are never allowed to hang your king, yet you are openly hanging your king to deliver checkmate.

Take the chess position someone posted earlier in the thread for example. The queen is on b2, king on c1 and a8, and bishops on a3 and a6. Pins aside, why cant you deliver checkmate? This can be explained as follows:

You are never allowed to hang your own king in order to deliver a threat to another king.

 If you agree that this is an absolute law of chess, surely you can see the logic behind why we have this rule.

It was created to confront and patch this loophole of allowing your king to hang and to uphold this law of chess.

Hi JkCheeseChess,

Checkmate definitely does not exist simply because "people back then were too lazy to play out one more move." You claim that "'checkmate' exists because there is no need to continue the game if the king has no legal moves." This is simply not true. Stalemate also happens when the king has no legal moves, but a stalemate is a draw. The reason stalemate is treated different from checkmate is that chess is meant to be a delicate game, where a victory is only achieved through checkmate. Chess is not about trapping the king; otherwise, a stalemate would also be a victory. If chess is about capturing the king, why are there so many rules aimed at preventing situations where a king can be captured (can't hang kings like you can hang other pieces, can't move pieces off pins to the king, etc.)?

______

Hi reysbull,

Yes, we both agree that "you are never allowed to hang your own king in order to deliver a threat to another king." If you should never be allowed to hang your king, then why do you claim (a few sentences later) that "[the king capture] was created to confront and patch this loophole of allowing your king to hang." We both just agreed that players should never be allowed to hang their own kings. We also agree that there is currently a loophole of allowing your king to hang. Why not just get rid of this loophole and force players to address king capture threats so that kings are never hanging (like in standard chess)? As I explained above, so much of chess is predicated on not ever allowing the king to be captured. Allowing king captures in some situations and not in others (e.g. hanging kings, moving pieces off pins, etc.) in violation of many standard chess rules should not be the solution to this loophole. The solution is to get rid of the loophole.

To your move order point, you claim that "because of the law of move order, you would first have to react to your own king in danger before delivering checkmate." If players must first react to their own king in danger before delivering checkmate, why do they NOT have to react to their own king in danger before capturing a king? This super-priority of king captures simply cannot be explained without making contradictory statements because it violates such a fundamental principle of chess.

Allowing king captures has created so many difficult questions. Forcing players to address king capture threats would eliminate all of them. Most of all, the current ruleset breaks the most fundamental of all chess rules: a player wins by checkmate.

Stalemate isn't counted as a win not because chess isn't about trapping the king, but because there are many positions that should be drawn. In stalemate, any move will put the king in danger of being captured. Checkmate definitely should not take priority over king captures because consider in 2pc, if a king is able to be captured, it was likely checkmate last move, (Or someone made a blunder that walked their king into an attack but we'll ignore this) as you can see in the 2pc variant where you have to capture the king to win.