It seems to me that the rules need clarification with respect to stalemate. It is easy to create ambiguities when messing with the king rule :/
The basic idea of this variant is to enhance the king rule. After a side moved, not only must their king be not attacked, but there must also be a square next to the king not attacked by the opponent and not occupied by a friendly piece.
The game ends if a side cannot make a legal move. Here this means: if there is no pseudolegal move which fulfils both demands of the enhanced king rule. Then it is either checkmate and the opponent wins, or it is stalemate and the game is a draw.
In orthodox chess, checkmate is when the king of the side to move is threatened, i. e. attacked. But here, the concept of the king being threatened may be enhanced, as the enhanced king rule suggests: the king is threatened if one of the two demands of the king rule is not fulfilled. That would mean that stalemate does no longer exist. If both demands are fulfilled, i.e. the king is not threatened, then the king has a square to move to and there is a legal move (because the king is, after the move, adjacent to the square he just moved away from so that the second demand is again fulfilled).
But one could also stay with the usual definition of "threatened". Then, if the king is not attacked and has no square to move to and no other piece can legally move, it would be stalemate and a draw.
The former appeals more to me, and I'm going to clarify the rules accordingly.
BTW the "adjacent to queen" rule is also interesting, it would solve the problem of black being checkmated at the very beginning of the game. But it is not really necessary. I want to keep it as simple as possible and just declare the beginning of the game an exception.
It seems to me that the rules need clarification with respect to stalemate. It is easy to create ambiguities when messing with the king rule :/
The basic idea of this variant is to enhance the king rule. After a side moved, not only must their king be not attacked, but there must also be a square next to the king not attacked by the opponent and not occupied by a friendly piece.
The game ends if a side cannot make a legal move. Here this means: if there is no pseudolegal move which fulfils both demands of the enhanced king rule. Then it is either checkmate and the opponent wins, or it is stalemate and the game is a draw.
In orthodox chess, checkmate is when the king of the side to move is threatened, i. e. attacked. But here, the concept of the king being threatened may be enhanced, as the enhanced king rule suggests: the king is threatened if one of the two demands of the king rule is not fulfilled. That would mean that stalemate does no longer exist. If both demands are fulfilled, i.e. the king is not threatened, then the king has a square to move to and there is a legal move (because the king is, after the move, adjacent to the square he just moved away from so that the second demand is again fulfilled).
But one could also stay with the usual definition of "threatened". Then, if the king is not attacked and has no square to move to and no other piece can legally move, it would be stalemate and a draw.
The former appeals more to me, and I'm going to clarify the rules accordingly.
BTW the "adjacent to queen" rule is also interesting, it would solve the problem of black being checkmated at the very beginning of the game. But it is not really necessary. I want to keep it as simple as possible and just declare the beginning of the game an exception.