[Retros] Solidarity chess (=SC)

[Nicolas Dupont]

Note that, in general, giving check has nothing to do with threating  
to capture the opponent King! Although this is of course the correct  
definition in the orthodox setting, this is not true for most fairy  
conditions. For example, under the SAT condition, a side is in check  
if its own King can move (via a legal move in the orthodox sense).

You can simply define a fairy condition by claiming, e.g., that a side  
is in check if it can move one of their rooks. Then from the initial  
game array, 1.e3 d6 2.Qh5 Bf5 3.Qxh7+ is a checking move and the only  
way to parry it (hence the only legal black answer under this  
condition) is to play 3
Bxh7, to close the Rh8-cage.

So what is the definition of a checking move? The best consistent way  
I see is precisely to threat winning the game
 If one decides to  
follow this convention, then there are two kinds of SC-checking moves:  
threatening to capture the opponent King (via a SC-legal move), or  
threatening to break the opponent solidarity (via a SC-legal move too).

We don't have to be afraid, in fairy chess, to face checking moves  
which are far from the orthodox ones!

Best,

Nicolas.