Comments/Ratings for a Single Item

I think your second option is what I mean. But I'm not too sure, so let me clarify.

1st. standard checkmate would be a win, since the king is in danger so the player must aleviate the check (by king's rules), but since he can't he has no legal moves, thereby loses (by rule 1).

2nd. in addition to standard checkmate, stalemate would be loss as well, since by rule 1 the person with no legal move loses. A example would be if white king at A1, and black rook at B2, with white having no other pieces, and black having pieces elsewhere. If it is white to move, then white is lost, since his only piece the king can't move without placing itself in danger which is forbidden.

So checkmate in Nach Schach is a form of stalemate, and is still a valid way to win, however stalemate is sufficient, so sometimes there can be simpler way to win without explicit checkmate.

By the way it would be intersting to work out lone king win against lone king, hint it is a win by stalemate.

Finally I have a subvariant which I'll post later that adds a random setup on a slightly larger board, which I consider better than Nach Schach itself.

Rich,

 I have a certain aversion to castling as I find the castling rules fiddly, but your point is well taken. For Nacht Schach, castling does make some sense. So it can be used as an optional rule. 

In other games of this yet unposted series of variants, the topology and rules is such that castling will be unnecessary. (i.e. there's room to move rook back.)

Jianying Ji,

I also find castling fiddly, but also see if you don't have it, protecting the king and mobilizing the rook is shorted.

I do believe the 8x7 board (Simplified Chess Board) does provide solid merit though, considering that Henry VIII Chess also uses it.  I also have Simpleton's Chess, which is like Henry VIII but simplier also uses it.