[xnorswap]

E4 Bc4 Qf3 Qf7#

There is no check there until checkmate is delivered.

If the enemy is then allowed to play 4 moves to capture the queen while the king is in check then that implies illegal moves are allowed in the intermediate moves.

But if illegal moves are allowed then white can open with 1. Qxd8 Qxa8 Qxh8 Qd1 because once illegal moves are allowed then the whole game devolves a step further.

Accurately encoding the rules of games in a manner that does not allow for loopholes is a really hard problem. Just look at golf. A simple game in which you hit a ball into a hole in the shortest time yet the "official" (R&A) rules run to 230+ pages and has frequent updates to fix issues.

Cricket appears to be a far more complex game yet the laws of cricket as published by Wisden actually comes in at a slightly shorter 208 pages.

[zimpenfish]

> you hit a ball into a hole in the shortest time

Technically the "fewest number of strokes" rather than "the shortest time", I think?

(apologies if there's a speed-golfing community)

[Someone]

There is, with each stroke counting for 60 seconds (https://en.wikipedia.org/wiki/Speed_golf)

[jjnoakes]

> that implies illegal moves are allowed in the intermediate moves

Seems simple enough to define illegal moves as moves that end your turn in check, which is basically the same definition as regular chess. I don't immediately see the problem there.

> if illegal moves are allowed then white can open with 1. Qxd8 Qxa8 Qxh8 Qd1

This isn't the same thing at all...

[xnorswap]

But the rule in chess is actually:

> No piece can be moved that will either expose the king of the same colour to check or leave that king in check.

And you're right that you can re-write that rule, but my point is that it needs to actually be done here, which it hasn't been.

I'm not trying to shit on these rules, I'm just highlighting the difficulty in actually writing consistent rules.

[jjnoakes]

Right, I didn't say the rule in chess was exactly that, but "basically" that - which effectively is the same.

The rules could certainly be written out in more legalese, but I found them easy to understand as-is without resorting to suggesting that the queen could also start ignoring and moving through pieces at will.