H. G. Muller wrote on Sun, May 3, 2020 06:53 PM UTC:
I don't like the term pseudo-legal, because it suggests something that is legal-like without actually being legal. For example, pseudoscience is understood to be fake science, not something that could sometimes be real science but doesn't have to be.
I agree, but it happens to be the standard term. It is a very useful concept, so I think that when we don't like the name, we should just find another name for it. I already coined the term 'valid move'. I suppose 'semi-legal' suffers from the same problem as 'pseudo-legal'. 'Proper move' would be another possibility. A problem is that for these terms it is not obvious that they might conflict with legality. How about 'near-legal' or 'close-to-legal'?
This is covered by the condition that it has to have a capturing move to the space. An emperor does not have a capturing move to a space occupied by a protected royal piece.
I don't think so. The Emperor does have a pseudo-legal move to that square. That it cannot use it is just because it would expose itself (the royal) to capture, just as moving a pinned piece would. So if you mention pins as an example of things that should not be taken into account for game-terminating moves, it is not obvious at all (and would even be very illogical) that stepping into check with the royal itself would not be excluded too. Note that in the FIDE case K x K is allowed, even when the captured King is protected: I cannot step my King next to the enemy King even when my King is protected there. You would be able to do that in Recursive Chess, btw.
I agree, but it happens to be the standard term. It is a very useful concept, so I think that when we don't like the name, we should just find another name for it. I already coined the term 'valid move'. I suppose 'semi-legal' suffers from the same problem as 'pseudo-legal'. 'Proper move' would be another possibility. A problem is that for these terms it is not obvious that they might conflict with legality. How about 'near-legal' or 'close-to-legal'?
I don't think so. The Emperor does have a pseudo-legal move to that square. That it cannot use it is just because it would expose itself (the royal) to capture, just as moving a pinned piece would. So if you mention pins as an example of things that should not be taken into account for game-terminating moves, it is not obvious at all (and would even be very illogical) that stepping into check with the royal itself would not be excluded too. Note that in the FIDE case K x K is allowed, even when the captured King is protected: I cannot step my King next to the enemy King even when my King is protected there. You would be able to do that in Recursive Chess, btw.